The one thing I will share with those new to jetting, is that it is often easier to feel the dead spots that it is to hear them. Sometimes going down the street in third gear, and doing a weighted pull through the RPM range with a load, can be more helpful than just revving a static bike - it all depends on your sensitivity and what may work best for you. Once you've done this enough, you may be able to get it closer, just by listening - similar to the way Mitch is figuring things here. Cool video, Greg!
Yeah man I'd pay just to get Mich Payton to rev my bike a few times. 😁. I always go with pro circuit if I'm getting an aftermarket exhaust because I've seen so many examples of mich being a good guy and if I'm gonna spend the money I'd prefer to support good people.
He is an artist and there not many in the world that knows how to like him. So pumped for you budd, such a nice experience. Also happy that i was a miniscule part of it.
I have a god tip. Find some guy over the age of 55, who tuned his own 2-stroke engines in the 80's and 90's, and have him help you. You will find that experience at vet races. look for the bikes with the least amount of smoke,---and pay the man. Now, we used to get good tech information from MXA, but they don't know how to jet a carb either today. Jody does I bet. But the kids don't listen to their elders today,--so they are starting from scratch.
Man, Mitch is my favorite person and I’ve never even met the guy or seen him in the flesh, just going off of his Whiskey Throttle interviews and occasional calls on Pulp. I consider it an honor to do something so involved with him like this. Also, bike looked bitchin’ in Bham last week in the pits.
He is such a cool dude in person! Hopefully you'll get to meet him someday. Too bad he wasn't at Birmingham, I'm assuming he'll be at Nashville though! Maybe see you there too?! Thanks dude💨
I’m currently building a 2003 KX250 and I’m about to jet the carb for southern Utah where I live. I too hate jetting carbs and have no idea what I’m doing so I ordered a JD jet kit. I’ll let you know how that goes but I’m sure you’ve used them before.
Right on Brandon! I'm a big fan of the JD jetting kits. They are very informative and direct you what to use based on your elevation and temperature. Let me know how it works out for you. I miss being in Utah to ride in St. George, etc
Greg, all you had to do was just ask. That year(99) used an odd ball jetting spec, not that the later years KX250 were any better, but that 99 was a little different the rest.
I have a tip for the YZ250 (mine a 2019). I am still a tad on the rich side, but way better than stock. Michigan riding. Pilot 48 from 50. Air screw about 1.5 turns out. Replace needle with the next leaner N3CW from the stock N3EW, and still at the top groove. Power jet from a 50 to a 40. Main jet still stock 178. I may drop to a 175 for a lighter brown color plug at full throttle. I also have higher compression than stock (burns hotter, leans the jetting a bit), and run 100 octane fuel. FMF Gnarley pipe, V-force reeds with no stock aluminum spacer between the reed and cylinder. Lowered the cylinder with no cylinder base gasket for more low end power with that pipe and reeds. Seal it perfectly with a good sealer that resists gas. (not silicone). Engine is a tad softer to top, but rips much harder from lower rpm's, and still smooth. Jetted at 65 deg F. outside. One of the best motors I ever had now. Mission accomplished. Doug in Michigan
That's awesome that he/they could get it dialed in so well just by revving it in neutral. I've always done that to get a baseline, but I thought you had to ride it to put a load on the engine to get a more precise "butt dyno" reading. Thanks for sharing, Greg.
Greg, I agree with the T4 recommendation. Personally, I prefer C12 with Castor 927. You lose the oxygenation, so you don't have to worry about that jetting issue, but you also get leaded and it has a bit higher octane. For me, I like that I can run OEM spec on the carb with C12.
Some places sell 93 octane alky free race fuel from a gas station, depending on your area, (my area only sells 90 octane alky free. Not good enough for stock compression). If you are using stock compression, that is a good choice.
Hi there Greg, I normally would use the good old C12 and just leave it alone. It's so much more forgiving and less fussing with jetting. However, what you are doing is perfectly fine. I'm sure Mitch made you aware of the shortcomings and reliability issues you can face when running the T4. Your jetting has to be spot on for the elevations and temps.
What about T2? I am finishing up a rebuild at the moment and want to stick with a solid fuel that will treat my bike well. Is there anything specific I should know about running T2? Is there a better alternative?
That's for sure! They couldn't stress enough about how consistent and reliable C12 is across the board. That's why they trust it so much. Looking forward to doing some more fuel testing. Thanks for the response dude!
I'm actually not familiar enough with T2 to comment on it. I want to make an educated guess that you'd have to run a richer setting because of the oxygen content in T2. I'd love to ask Mitch or Schnike the next time I see them about their thoughts on it. Thanks man!
I like messing with the needle. My 03 has basically the same motor and people say the Suzuki needle is good but I think I have the ktm250sx needle in there now and I really like it. It’s the closest to the Suzuki but has a different taper. Theres threads about it on ThumperTalk. You can lean out the middle and different areas with the needle and make the bike feel different, I think.
I think people over look the needle profile far too often. That is what makes jd jetting look so good...lol. They do know their sh/t. Loving the build.
I'd like to do some different needle testing too! Maybe even go a hair richer with it. Especially if I decide to stick with the oxygenated fuel. Thanks dude!
Yeah on my 4 stroke I'm running a needle hardly anybody knows about with a shaved down slide and it's wildly different from how the FCR carbs perform stock. I've also added shit like the boyesen qs3 and a deeper sump cause why not. Crisp consistent power
Thank you so much for this video! It helped me dial in some jetting issues I was having with my 98 that it desperately needed! I would be so hyped to be at the PC shop and Mitch revving my bike like that! 😂 what an awesome experience. My only issue is I am running on 93 ethanol free pump gas which is runs great as it is but I would like to find some good race fuel for it which I have zero experience running.
If you are not going to raise your compression higher than stock, there is no need to go higher than the alky free 93 you are running now. I wanted more lower end power form my 2019 YZ250, and I got it with out much top rpm loss, (I forgot to put a tach on it when it was stock). I got more compression by not using a cylinder base gasket (sealed it with a good sealer, and squish clearance is an acceptable .048". min for a 250 is about .040"), so I have to run 100 octane fuel, (I mix pump alky free 90 with 110 race fuel to save money).
I was a test rider in the 90's and we did a lot of testing with porting, reeds, exhaust, jetting specs, oils, timing specs, etc. There is one thing you can try, I saw your running 927 there are a couple of things you should know besides being hands-down the best smelling 2 stroke oil ever made , first off 927 is a great lubricant but it is super dirty and builds up carbon in the exhaust which makes the power valve get sticky, the other thing is it makes the bikes jetting very finicky especially with elevation changes. Bottom line if your gonna run it plan on servicing your power valve more often and get used to the weird traits your motor will have, If your not real witty with jetting I would run Motul or Motorex. Ive been racing shifter karts for a long time and we run Motul because the motors are always at high rpm and we have never had a engine failure, by the way we run at 24.1. If your doing MX run 32.1 you can't go wrong. Good luck!
Sounds pretty sound to me. I do know a company in Weed CA. named "Quick Draw". They build 30cc RC boat racing engines, (over 8 hp at 16,000 rpm peak), and cast/sleeve their own cylinder with more modern porting (bridged exhaust port for one, than the high volume race engines from Zenaoh, which I build for a living. Ported with a CNC mill and hand finished). But they use a Zenoah crank, and have had problems with the lower rod bearing cage. They were forced to test oils and run them hard on their water brake dyno, (16,000 rpm peak power, full throttle, 1/2 hr.). I have not talked with those guys ion over a year, but at last, the love the Motul Kart GP 2-t oil (very expensive), and the klotz Supertechniplate with 20% Caster blended with syn. They say the lubricity is pretty much the same, but the Klotz burns more dirty (Motul is super clean, great oil). But IMO, good crisp jetting keeps the build up to a minimum, and not even MXA understands how to jet a carb today, so it seems like some kind of black magic to people today. If we race, I guess the cut off age of people who know how to jet a carb is about 55 years old today. :) Find a vet racer who's bike sounds great and does not smoke much kids, and be his friend. :) This are the only guys I know who actually did durability testing for oil on their dyno. Doug in Michigan
So my thing is these bikes aren’t running super high compression compared to their four stroke counterparts so is there really any advantage of running C2 instead of pump gas 91(what I have in my city) for example, an 06 KX 250 has 10.2 compression and my 2022 CRF 450 has 13.5-1 compression i’m not really too knowledgeable in it, but I don’t see it really improving too much on the two stroke power wise so why the fancy fuels on relatively “low compression”engines, not low compression, but not high enough for super high octane if that makes sense
The first thing that came to my mind about rejetting to oxygenated fuel is can't you calculate it. The amount of oxygen is a known fact in percentage. Not sure if that would work but I would assume you will get pretty close. The other option is to put it on a dyno and use a wideband O2 sensor to figure out the afr and compensate. In the end the laps at the track are telling the only true story I guess. I think everyone here is pretty jealous you were there, with Mitch Payton, working on your bike. Awesome experience man !
That would be interesting to throw it on a dyno and figure out that calculation. I've got a shop near me who could potentially do it for me. Keep you posted if I do! Thank you 🙌🏼💨💨
@@GregHitchko If you have that opportunity that would be really interesting. Cool stuff !! Of course it can never beat having Mitch working on your bike 😇
With race fuel, you have to verify if it’s compatible with 2-stroke oil. Some VP fuel was reformulated a year ago and is no longer compatible. The oil will separate and you will seize. VP C-12 is a very good 2-stroke fuel for all but pros, where rules don’t allow lead. Some race gas has components that make the bike run great, but will evaporate overnight.
I got Vp 108 octane from the pump for 14$ a gallon I had to drive 50 mile round trip but it was nice rural backroads w 65° weather w the top down in my Honda S2000 was a fun ride and good deal I think 😊
@@GregHitchko Well, when today's MXA says the YZ250 2-stroke is jetted well,---they could use the skill. They are fine riding a oily mess with 3 less hp. I guess the kids don't talk with Jody.
If your compression is stock, all you need is 93 octane (ron/mon method). Alky free is better IMO if you can get it. Lead or not is not much of a performance difference until you have high compression for competitive racing. Alky can attack some of the rubber parts of the carb over time, so that is good to stay away from. Carbs that are designed for alky, (often used in drag racing for example), can replace the rubber parts with neoprene parts, and run about twice the fuel compared to gas. They gain power with higher compression than gas can tolerate, or they would not make more power than gas. :) This is why "flex fuel cars", (that run both gas and E-85, (85% ethanol/15% gas), with a fixed lower compression for gas,---run better with gas. If you have stock compression, can find 93 octane or higher, (waste of money going higher with stock compression though, but won't hurt anything), with out alky,--you are golden. :)
Mr. Greg, here's a suggestion : take your beautiful KX , come with it to Israel ! here there is only one kind of fuel, unleaded, clean without alcohol, put 1:32 pre mix of your favorite oil - no more worries with which fuel to use , and RIDE TILL YOU CAN'T HOLD ANYMORE 😉
I have an oem dome that was cut for C12 by pro circuit, to raise the compression. But I'm actually running a Phathead cylinder here with a stock dome. Mitch and Schnike said it was still fine to run the C12 with the stock compression dome
Almost never. 2-strokes with carbs are shipped rich so they are safe with different air quality from all over the world. Some are better than others, but they all could benefit from better jetting for your area. The YZ250 2-stroke (mine a 2019), wow, super rich. I just got done almost finalizing my jetting, and man I had to do a lot. 48 pilot replaced the 50, The next lean needle in the owners manual replaced the stock needle, and still at the top groove. The power jet went to a 40 from a 50,, and for now, I left the main stock. I am still spitting a bit of un-burnt oil from the silencer, (stock was so rich, spitting oil droplets ruined 3 of the backs of my jerseys.). I am still a bit on the rich side. I like it when all the oil is burning, and no mess coming from the pipe.
Is it possible to sell one of these bikes you've built for the amount of money you put into them? Or would you take a loss if you tried to sell them? Do factory bike builds like this hold any value other than sentimental?
If you are racing against 450's on today's fast MX tracks,--none of them are worth it. I would bet the only people willing to put up the money are vet riders who despise the EPA for forcing the 4-stroke on the industry, and won't buy one based on morality.
Run as high octane non ethanol/oxy as you can get. Honda says 110 for 2005-2007 CRs. Could be same for '03. I got dome reshaped for my 2006 so as to run 98-100 pump gas @ 40:1 motul 800. I would not use 927 .
The only time you "have to jet" is if you are too lean and fry the engine, or too rich and foul a plug. You can ride around on messy stock jetting if lean enough to not foul a plug. But if your plug is not a light brown color and dry, (but black and even wet. Ready to foul.), you are probably missing some power in the entire curve, and about 2-3 hp peak for a 250. Jetted well, the pipe is not oily messy anymore, the exhaust power valve stays clean longer, less carbon build up in the top end and power valve, coolant water heats up a lot faster, and can help avoid piston damage from taking off with too cold of coolant. Jet the engine after all the mods are done, and using a clean air filter.
Here in England Britain and Ireland it is impossible to get fuel as low grade as 88 octane. Lowest you can get at the pump is 95. Super unleaded at the pump is 99 octane sum places. I always always use super in my bikes. If I put even 95 in my R1 or gsxr superbike a I noticed it . Can’t imagine putting 88 innit lol
pump gas in the UK is rated differently than in the US. The UK uses research octane number. This is a higher octane number.The US test uses motor octane number. This is a lower octane number.At a US pump the octane number is called the pump octane number. To get PON you add RON plus MON and divide by two. Basically 95 octane at a UK pump is equal to 91 octane at a US pump.
UK and Europe does not use the same measuring method for octane, your UK gasoline is advertised in 'RON' (research octane number), in north america the AKI (anti-knock index) or R+M/2 (average of RON and MON) are used. Your 95 RON pump premium is equal to 91 AKI. Our low grade 87 octane is equal to your 91 RON.
Why in the world are you opposed to running leaded fuel? Two strokes love lead !!!!!! It is a lubricant , anti scuff agent . octane improver and the fuel is stabil for long lay ups. Oxygenated fuels are also corrosive so you really need to clear the fuel system after each use. And VP-2T IS Oxygenated. I found out when it corroded the needle in my perfectly jetted 2 stroke. It began to run all Fed up down low and I found the needle had been pitted on the straight section. New needle and Back to C-12 for me after that.
The FIM/AMA forcing out the lead for pro 2-strokes made them even less competitive with the 4-strokes. If this cat is against leaded race fuel, he either has the EPA or FIM/AMA on the brain too much. :)
you went through all the recomended seetings and decided not to go with the recomended fuel..thats crazy. if you can ship the bike then you could have gotten the correct fuel...
C12 is a much better fuel for a motor that has some work.if its stock then t-4 is more than you need.you only need enough to stop detonation.just before detonation is your best power
@@GregHitchko have not tried that fuel yet. But when i was racing motocross with a stock motor just a pipe. I found the best set up was 87 octane for 3 gallons and 2 gallons of c12. I would notice better throttle response and no occasional lean pop when in deep sand. When i grass dragged stock snowmobiles the best runs where with garbage fuel
@@GregHitchko its all about burn speed. The higher the octane the slower it burns. There is alot more of course but it boils down to burn speed. Advance the timing to get it to fire a tic faster when piston is closer to tdc it detonates. So you raise octane so it burns a little slower and it will burn slower and not detonate. You will get guys saying no way blah blah blah. But remember things happen at a millisecond. So a small change goes far.
Had a 07 kx 250, when I bought my PC pipe and silencer they gave me all the info for my jetting. I believe it was from James Stewart’s bike. Bike rode fine on 91 octane. Also use iridium plugs big difference, stay away from that race gas you’ll blow a motor.
That's really cool! I wish there was something higher than 88 non ethanol out of the pump around me. Higher compression engines definitely take a away from the reliability of a stock engine just a little bit
That can happen by just changing your gas/oil mix ratio too. In fact, you can fine tune your jetting by using a bit more or less oil in the gas. (less oil for a bit richer fuel/air ratio.).
@@Randy_Cox I agree. I was just making a point in reality. But, if you want to fine tune with the gas mix, with a great oil, I would stay between 50:1 and 30:1. That is quite a bit of adjustment for jetting overall, but i jet for 32:1, and just finished my YZ 250 today. I ended up going more lean for every jet. Pilot, leaner needle (N3CW), and still at the top groove, the leaner power jet (I don't care for power jets, and don't think they are needed, and just complicate things). and last will be a 175 from the stock 178 main jet. It was the most rich bike stock I ever had by far, and I raised the compression first, (now running 100 octane),, which did lean it some. MXA said it was jetted very well. I guess the kids don't talk with Jody.
If he did not switch back and forth with oxygenated fuel, (just stayed with alky free race fuel of the octanes he needs), he probably would not have much, if anything, for jetting changes. I never ran oxygenated fuel. But just the name says,---"change/richen your jetting', to me. :)
@@GregHitchko Glory be, I hears y'all, yes I own a 89 cr250 with the pro circuit pipe and muffler, and I did a little local motocross on my long gone 84 Cr500r..Trump 2024, keep petrol power 4ever.🤠🇺🇸👍🍻
Best things about California. We make twice as much as other states, our houses are worth twice as much, and we can still ride any dirt bike we want since we sell out of state OHV stickers. Only thing that costs more here is the gas, which is right at 5$. Bikes, cars, and food cost the same as other states 😂. Oh yeah and pro circuit and alot of the big name motocross companies reside here.
The one thing I will share with those new to jetting, is that it is often easier to feel the dead spots that it is to hear them. Sometimes going down the street in third gear, and doing a weighted pull through the RPM range with a load, can be more helpful than just revving a static bike - it all depends on your sensitivity and what may work best for you. Once you've done this enough, you may be able to get it closer, just by listening - similar to the way Mitch is figuring things here. Cool video, Greg!
Mitch is an awesome guy and I love his passion for the sport of off-road motorcycles. Great guy for the industry.
Mitch has had such a positive influence on the sport. Massive to think about it. So grateful to have him 🙌🏼
Mitch is an ICON for the sport!
Yeah man I'd pay just to get Mich Payton to rev my bike a few times. 😁. I always go with pro circuit if I'm getting an aftermarket exhaust because I've seen so many examples of mich being a good guy and if I'm gonna spend the money I'd prefer to support good people.
He is an artist and there not many in the world that knows how to like him. So pumped for you budd, such a nice experience. Also happy that i was a miniscule part of it.
It's a true art that is for sure! Very much appreciated my dude 🙌🏼💨💨
I have a god tip. Find some guy over the age of 55, who tuned his own 2-stroke engines in the 80's and 90's, and have him help you. You will find that experience at vet races. look for the bikes with the least amount of smoke,---and pay the man. Now, we used to get good tech information from MXA, but they don't know how to jet a carb either today. Jody does I bet. But the kids don't listen to their elders today,--so they are starting from scratch.
Wow I feel like I can hear a change in the exhaust note between the fuels. The C12 seems a little throatier. Throat goat.
Right?! It's crazy how it cleaned it right up.
The front and rear fender look so good on them late 90’s bikes
Big fan! No thanks to the restyle kits 💨💨
I started boring out the openings on my main jets. Im still testing but seems to have better pickup
Man, Mitch is my favorite person and I’ve never even met the guy or seen him in the flesh, just going off of his Whiskey Throttle interviews and occasional calls on Pulp. I consider it an honor to do something so involved with him like this. Also, bike looked bitchin’ in Bham last week in the pits.
He is such a cool dude in person! Hopefully you'll get to meet him someday. Too bad he wasn't at Birmingham, I'm assuming he'll be at Nashville though! Maybe see you there too?! Thanks dude💨
@@GregHitchko Absolutely going to Nashville! I live halfway between there and Bham up in Huntsville so it’s too close to miss.
@@cbh148 right on! Huntsville is actually where I bought the KX lol. Cool area. Yeah definitely way too close not to go 🙌🏼💨
I’m currently building a 2003 KX250 and I’m about to jet the carb for southern Utah where I live. I too hate jetting carbs and have no idea what I’m doing so I ordered a JD jet kit. I’ll let you know how that goes but I’m sure you’ve used them before.
Right on Brandon! I'm a big fan of the JD jetting kits. They are very informative and direct you what to use based on your elevation and temperature. Let me know how it works out for you. I miss being in Utah to ride in St. George, etc
You didnt leak down test the motor after rebuilding it??
Greg, all you had to do was just ask. That year(99) used an odd ball jetting spec, not that the later years KX250 were any better, but that 99 was a little different the rest.
That kx 250 right there is the best looking dirt bike I've seen in my life.
Haha thanks my man!
I have a tip for the YZ250 (mine a 2019). I am still a tad on the rich side, but way better than stock. Michigan riding. Pilot 48 from 50. Air screw about 1.5 turns out. Replace needle with the next leaner N3CW from the stock N3EW, and still at the top groove. Power jet from a 50 to a 40. Main jet still stock 178. I may drop to a 175 for a lighter brown color plug at full throttle. I also have higher compression than stock (burns hotter, leans the jetting a bit), and run 100 octane fuel. FMF Gnarley pipe, V-force reeds with no stock aluminum spacer between the reed and cylinder. Lowered the cylinder with no cylinder base gasket for more low end power with that pipe and reeds. Seal it perfectly with a good sealer that resists gas. (not silicone).
Engine is a tad softer to top, but rips much harder from lower rpm's, and still smooth. Jetted at 65 deg F. outside. One of the best motors I ever had now. Mission accomplished. Doug in Michigan
That's awesome that he/they could get it dialed in so well just by revving it in neutral. I've always done that to get a baseline, but I thought you had to ride it to put a load on the engine to get a more precise "butt dyno" reading. Thanks for sharing, Greg.
You do. Some people are really good at the "no load baseline", but an engine under load and hot needs more fuel.
I had the 98 version that was bakers bike. Beautiful neon frame and plastics. Wish I could find it again bought it in 99 through dryer Motorsports.
I heard people liked the 98 way better than the 99. Here's to hoping you come across that bike too! 💨
Greg, I agree with the T4 recommendation. Personally, I prefer C12 with Castor 927. You lose the oxygenation, so you don't have to worry about that jetting issue, but you also get leaded and it has a bit higher octane. For me, I like that I can run OEM spec on the carb with C12.
Some places sell 93 octane alky free race fuel from a gas station, depending on your area, (my area only sells 90 octane alky free. Not good enough for stock compression). If you are using stock compression, that is a good choice.
Hi there Greg, I normally would use the good old C12 and just leave it alone. It's so much more forgiving and less fussing with jetting. However, what you are doing is perfectly fine. I'm sure Mitch made you aware of the shortcomings and reliability issues you can face when running the T4. Your jetting has to be spot on for the elevations and temps.
What about T2? I am finishing up a rebuild at the moment and want to stick with a solid fuel that will treat my bike well. Is there anything specific I should know about running T2? Is there a better alternative?
That's for sure! They couldn't stress enough about how consistent and reliable C12 is across the board. That's why they trust it so much. Looking forward to doing some more fuel testing. Thanks for the response dude!
I'm actually not familiar enough with T2 to comment on it. I want to make an educated guess that you'd have to run a richer setting because of the oxygen content in T2. I'd love to ask Mitch or Schnike the next time I see them about their thoughts on it. Thanks man!
Hate castor 927 since they don't put any dye in it. Even when I label my tanks well, I still get paranoid ^_^
I'm surprised pc didn't run it on the dyno if just to see the afr readings through the range.
Shell in Spanish fork has VP110 at the pump.
Too bad I'm not in Utah anymore 😭
Dude worker bee that’s spectacular 😂😂😂😂 so true and prolly one of the best selling two strokes moves of all time!!!! Lol
I like messing with the needle. My 03 has basically the same motor and people say the Suzuki needle is good but I think I have the ktm250sx needle in there now and I really like it. It’s the closest to the Suzuki but has a different taper. Theres threads about it on ThumperTalk. You can lean out the middle and different areas with the needle and make the bike feel different, I think.
I'm definitely going to have to look into this! I've heard other people say the Suzuki needle as well. Thanks for sharing dude!
I think people over look the needle profile far too often. That is what makes jd jetting look so good...lol. They do know their sh/t. Loving the build.
I'd like to do some different needle testing too! Maybe even go a hair richer with it. Especially if I decide to stick with the oxygenated fuel. Thanks dude!
Yeah on my 4 stroke I'm running a needle hardly anybody knows about with a shaved down slide and it's wildly different from how the FCR carbs perform stock. I've also added shit like the boyesen qs3 and a deeper sump cause why not. Crisp consistent power
Thank you so much for this video! It helped me dial in some jetting issues I was having with my 98 that it desperately needed! I would be so hyped to be at the PC shop and Mitch revving my bike like that! 😂 what an awesome experience. My only issue is I am running on 93 ethanol free pump gas which is runs great as it is but I would like to find some good race fuel for it which I have zero experience running.
If you are not going to raise your compression higher than stock, there is no need to go higher than the alky free 93 you are running now. I wanted more lower end power form my 2019 YZ250, and I got it with out much top rpm loss, (I forgot to put a tach on it when it was stock). I got more compression by not using a cylinder base gasket (sealed it with a good sealer, and squish clearance is an acceptable .048". min for a 250 is about .040"), so I have to run 100 octane fuel, (I mix pump alky free 90 with 110 race fuel to save money).
That's one bad ass bike
Thanks Jeremy! 💨💨
Good Saturday morning when the man uploads!
Haha thanks Wesley! Perfect timing for SX updates too🙌🏼. Thanks for watching man
Here to hear the bike. Sweet vid. My neighbors are about to hate me.
Haha let it rip my man! Who knows, they may love it 😂
Don't think of your neighbors as hating you. Think of then as "envying" you. And they would if they knew what is good in this world. :)
I'd love it if mine ripped bikes like me
I knew a guy that went by ear. Best running little 80 ever
It's wild how they can do it and be so precise. Super cool
I was a test rider in the 90's and we did a lot of testing with porting, reeds, exhaust, jetting specs, oils, timing specs, etc.
There is one thing you can try, I saw your running 927 there are a couple of things you should know besides being hands-down the best smelling 2 stroke oil ever made , first off 927 is a great lubricant but it is super dirty and builds up carbon in the exhaust which makes the power valve get sticky, the other thing is it makes the bikes jetting very finicky especially with elevation changes. Bottom line if your gonna run it plan on servicing your power valve more often and get used to the weird traits your motor will have, If your not real witty with jetting I would run Motul or Motorex. Ive been racing shifter karts for a long time and we run Motul because the motors are always at high rpm and we have never had a engine failure, by the way we run at 24.1. If your doing MX run 32.1 you can't go wrong. Good luck!
Sounds pretty sound to me. I do know a company in Weed CA. named "Quick Draw". They build 30cc RC boat racing engines, (over 8 hp at 16,000 rpm peak), and cast/sleeve their own cylinder with more modern porting (bridged exhaust port for one, than the high volume race engines from Zenaoh, which I build for a living. Ported with a CNC mill and hand finished). But they use a Zenoah crank, and have had problems with the lower rod bearing cage. They were forced to test oils and run them hard on their water brake dyno, (16,000 rpm peak power, full throttle, 1/2 hr.). I have not talked with those guys ion over a year, but at last, the love the Motul Kart GP 2-t oil (very expensive), and the klotz Supertechniplate with 20% Caster blended with syn. They say the lubricity is pretty much the same, but the Klotz burns more dirty (Motul is super clean, great oil). But IMO, good crisp jetting keeps the build up to a minimum, and not even MXA understands how to jet a carb today, so it seems like some kind of black magic to people today. If we race, I guess the cut off age of people who know how to jet a carb is about 55 years old today. :) Find a vet racer who's bike sounds great and does not smoke much kids, and be his friend. :) This are the only guys I know who actually did durability testing for oil on their dyno. Doug in Michigan
So my thing is these bikes aren’t running super high compression compared to their four stroke counterparts so is there really any advantage of running C2 instead of pump gas 91(what I have in my city) for example, an 06 KX 250 has 10.2 compression and my 2022 CRF 450 has 13.5-1 compression i’m not really too knowledgeable in it, but I don’t see it really improving too much on the two stroke power wise so why the fancy fuels on relatively “low compression”engines, not low compression, but not high enough for super high octane if that makes sense
Ran c16 in my 125 n 32:1 on the oil jetted the carb ran like a animal fired first kick every time
The first thing that came to my mind about rejetting to oxygenated fuel is can't you calculate it. The amount of oxygen is a known fact in percentage. Not sure if that would work but I would assume you will get pretty close. The other option is to put it on a dyno and use a wideband O2 sensor to figure out the afr and compensate. In the end the laps at the track are telling the only true story I guess.
I think everyone here is pretty jealous you were there, with Mitch Payton, working on your bike. Awesome experience man !
That would be interesting to throw it on a dyno and figure out that calculation. I've got a shop near me who could potentially do it for me. Keep you posted if I do! Thank you 🙌🏼💨💨
@@GregHitchko If you have that opportunity that would be really interesting. Cool stuff !! Of course it can never beat having Mitch working on your bike 😇
@@wernerxldata he's the two stroke master! They know what they're talking about there that's for sure 💨
Any reason why the preference to mix C12 with an oil additive over already premixed 40:1 VP T2 fuel?
I like running 32:1. I've heard T2 is great fuel but don't have much experience with it
It's hard to compare fuel and jetting when we live in Australia 🇦🇺
My preference in pipe is FMF FATTY...seem to get better overall performance
I'd love to do some pipe testing down the road! I've got a JSV cone pipe, and I'll have to pick up an FMF to compare as well. Good stuff dude 💨
With race fuel, you have to verify if it’s compatible with 2-stroke oil.
Some VP fuel was reformulated a year ago and is no longer compatible. The oil will separate and you will seize.
VP C-12 is a very good 2-stroke fuel for all but pros, where rules don’t allow lead.
Some race gas has components that make the bike run great, but will evaporate overnight.
Thanks for adding the knowledge about the race fuels man! Very interesting to note. I'll have to call and get the scoop on that. Much appreciated
I got Vp 108 octane from the pump for 14$ a gallon I had to drive 50 mile round trip but it was nice rural backroads w 65° weather w the top down in my Honda S2000 was a fun ride and good deal I think 😊
Why do you need 108 octane fuel? Did you raise the compression a lot from stock?
@@EarthSurferUSA yes I did raise the compression, not sure how much Eric Gorr did the work for me.
Moral of the story if someone has done the research and tell you what works dont listen to VP. They dont tune and build motors they sell fuel…
My dad was a genius with jetting bikes and building carbs not many masters left
Respect. Definitely not a skill that's highly needed in the sport anymore, but great to have 🙌🏼
@@GregHitchko Well, when today's MXA says the YZ250 2-stroke is jetted well,---they could use the skill. They are fine riding a oily mess with 3 less hp. I guess the kids don't talk with Jody.
Can i use c9 on yz250 2 stroke? its unleaded will it be fine pump gas are extremely bad in my country . I can get c9 from dealer any suggestion?
If your compression is stock, all you need is 93 octane (ron/mon method). Alky free is better IMO if you can get it. Lead or not is not much of a performance difference until you have high compression for competitive racing. Alky can attack some of the rubber parts of the carb over time, so that is good to stay away from. Carbs that are designed for alky, (often used in drag racing for example), can replace the rubber parts with neoprene parts, and run about twice the fuel compared to gas. They gain power with higher compression than gas can tolerate, or they would not make more power than gas. :) This is why "flex fuel cars", (that run both gas and E-85, (85% ethanol/15% gas), with a fixed lower compression for gas,---run better with gas. If you have stock compression, can find 93 octane or higher, (waste of money going higher with stock compression though, but won't hurt anything), with out alky,--you are golden. :)
Mr. Greg, here's a suggestion : take your beautiful KX , come with it to Israel ! here there is only one kind of fuel, unleaded, clean without alcohol, put 1:32 pre mix of your favorite oil - no more worries with which fuel to use , and RIDE TILL YOU CAN'T HOLD ANYMORE 😉
Haha you don't have to invite me twice!
sure go with whatever fuel you think will work... what does pro circuit know...not like they do alot of testing..
The audacity 😂
Are you running a higher comp head/dome?
I have an oem dome that was cut for C12 by pro circuit, to raise the compression. But I'm actually running a Phathead cylinder here with a stock dome. Mitch and Schnike said it was still fine to run the C12 with the stock compression dome
How’s those fox boots still holding up
Still like new since I've only used them like 4 times 😂. Don't get out as much as I used to lol
I’ve found factory jetting recommendations is always real close if not right on…
Almost never. 2-strokes with carbs are shipped rich so they are safe with different air quality from all over the world. Some are better than others, but they all could benefit from better jetting for your area. The YZ250 2-stroke (mine a 2019), wow, super rich. I just got done almost finalizing my jetting, and man I had to do a lot. 48 pilot replaced the 50, The next lean needle in the owners manual replaced the stock needle, and still at the top groove. The power jet went to a 40 from a 50,, and for now, I left the main stock. I am still spitting a bit of un-burnt oil from the silencer, (stock was so rich, spitting oil droplets ruined 3 of the backs of my jerseys.). I am still a bit on the rich side. I like it when all the oil is burning, and no mess coming from the pipe.
Dope bike!!
Thanks dude 💨
Is the C12 nonethonal fuel
Yes C12 is ethanol free!
holy!! awesome vid! love the bike too, I'm a zuke nuker myself, but beautiful kawi dude!
Haha thanks dude! It's been a fun build and experience 💨💨
Is it possible to sell one of these bikes you've built for the amount of money you put into them? Or would you take a loss if you tried to sell them? Do factory bike builds like this hold any value other than sentimental?
If you are racing against 450's on today's fast MX tracks,--none of them are worth it. I would bet the only people willing to put up the money are vet riders who despise the EPA for forcing the 4-stroke on the industry, and won't buy one based on morality.
my. only question is, will the engine behave differently with a load on it? Like should it maybe be in the dyno?
I feel like they always perform differently when you ride it than what the dyno says, right? Lol. If only I had. Dyno near me to run some testing
not a jetting expert im a lectron expert lol because its dummy proof and i love it
Haha that's fair enough! I've used them in the past as well 💨
Harbor freight is the only place I get bike stands! Thanks for keeping it real!😅
I really want a PC stand but I can't bring myself to spend the money 😂. The harbor freight stands are legit. Is four too many to have? Haha
@@GregHitchko I have 3 so no! 😅
Can anybody tell what I can run in my 2003 cr250r 2srtoke what fuel
Do you have any engine work done? High compression or is it stock?
Run as high octane non ethanol/oxy as you can get. Honda says 110 for 2005-2007 CRs. Could be same for '03. I got dome reshaped for my 2006 so as to run 98-100 pump gas @ 40:1 motul 800. I would not use 927 .
Pro circuit runs c12, its designed to run c12, it runs better with c12. Just run c12. Leave t4 for your lawnmower
What if I have a two stroke lawn mower 😂😂
@@GregHitchkoplease build a yz125 lawnmower.
Electrolux is supposed to keep you from having to jet. I always ran Boyson Powder Reeds & Boyson Float Bowl I never had the jet
The only time you "have to jet" is if you are too lean and fry the engine, or too rich and foul a plug. You can ride around on messy stock jetting if lean enough to not foul a plug. But if your plug is not a light brown color and dry, (but black and even wet. Ready to foul.), you are probably missing some power in the entire curve, and about 2-3 hp peak for a 250. Jetted well, the pipe is not oily messy anymore, the exhaust power valve stays clean longer, less carbon build up in the top end and power valve, coolant water heats up a lot faster, and can help avoid piston damage from taking off with too cold of coolant. Jet the engine after all the mods are done, and using a clean air filter.
Here in England Britain and Ireland it is impossible to get fuel as low grade as 88 octane. Lowest you can get at the pump is 95. Super unleaded at the pump is 99 octane sum places. I always always use super in my bikes. If I put even 95 in my R1 or gsxr superbike a I noticed it . Can’t imagine putting 88 innit lol
That is incredible to have that high octane at the pump!! I'm jealous haha. I'm assuming no ethanol either? Wish I could run that out of the pump 🙌🏼💨
@@GregHitchko £1.45 per litre here though so costs a fair bit more though. Maybe where you are race fuel is cheaper lol
pump gas in the UK is rated differently than in the US. The UK uses research octane number. This is a higher octane number.The US test uses motor octane number. This is a lower octane number.At a US pump the octane number is called the pump octane number. To get PON you add RON plus MON and divide by two. Basically 95 octane at a UK pump is equal to 91 octane at a US pump.
UK and Europe does not use the same measuring method for octane, your UK gasoline is advertised in 'RON' (research octane number), in north america the AKI (anti-knock index) or R+M/2 (average of RON and MON) are used. Your 95 RON pump premium is equal to 91 AKI. Our low grade 87 octane is equal to your 91 RON.
@michellatour150 what about Australia? Here our premium is 95 and we have 98 octane super premium. Our standard fuel is 91
Yeah i would stick to c12 or vp110 thats all i run in my cr, no pinging and no lean problems just 40:1 927 and runs like a dream
It's really hard to beat C12 in these bikes. It just runs so consistent and clean 🙌🏼
didn't Mike Brown rip that bike?
Why in the world are you opposed to running leaded fuel? Two strokes love lead !!!!!! It is a lubricant , anti scuff agent . octane improver and the fuel is stabil for long lay ups. Oxygenated fuels are also corrosive so you really need to clear the fuel system after each use. And VP-2T IS Oxygenated. I found out when it corroded the needle in my perfectly jetted 2 stroke. It began to run all Fed up down low and I found the needle had been pitted on the straight section. New needle and Back to C-12 for me after that.
The FIM/AMA forcing out the lead for pro 2-strokes made them even less competitive with the 4-strokes. If this cat is against leaded race fuel, he either has the EPA or FIM/AMA on the brain too much. :)
you went through all the recomended seetings and decided not to go with the recomended fuel..thats crazy. if you can ship the bike then you could have gotten the correct fuel...
If I can ship the bike I can do anything right? 😂😂😂
C12 is a much better fuel for a motor that has some work.if its stock then t-4 is more than you need.you only need enough to stop detonation.just before detonation is your best power
For sure! Im looking forward to testing out C9 which is the 96.8 octane too
@@GregHitchko have not tried that fuel yet. But when i was racing motocross with a stock motor just a pipe. I found the best set up was 87 octane for 3 gallons and 2 gallons of c12. I would notice better throttle response and no occasional lean pop when in deep sand. When i grass dragged stock snowmobiles the best runs where with garbage fuel
@@denniswilder3014 that is super interesting about the snowmobile grass drags with crap fuel. I wonder why lol?!
@@GregHitchko a motor only needs just enough octane to not detonate. The most power you will get is just before deto.
@@GregHitchko its all about burn speed. The higher the octane the slower it burns. There is alot more of course but it boils down to burn speed. Advance the timing to get it to fire a tic faster when piston is closer to tdc it detonates. So you raise octane so it burns a little slower and it will burn slower and not detonate. You will get guys saying no way blah blah blah. But remember things happen at a millisecond. So a small change goes far.
Sounds a tad lean on the needle
I'd like to explore richer needles here in the future 💨
She sounds crispy.
Proper killing it Greg 👍🏽that bike is so so sexy
Thank you Dan! Really appreciate it my man 💨
It's actualy lean loosing gas at high rpm lean main jet
Had a 07 kx 250, when I bought my PC pipe and silencer they gave me all the info for my jetting. I believe it was from James Stewart’s bike. Bike rode fine on 91 octane. Also use iridium plugs big difference, stay away from that race gas you’ll blow a motor.
That's really cool! I wish there was something higher than 88 non ethanol out of the pump around me. Higher compression engines definitely take a away from the reliability of a stock engine just a little bit
c16 or nothing hahaha that's what I'm doing in a 380cc big bore built on a trx 250r.
So you used a tune set for one fuel.....then used a different fuel and it didnt run right.😂🤣 Lesson learned i hope.
That can happen by just changing your gas/oil mix ratio too. In fact, you can fine tune your jetting by using a bit more or less oil in the gas. (less oil for a bit richer fuel/air ratio.).
@EarthSurferUSA wrong answer. The only correct ratio is 32:1 then learn how to jet a carb.
@@Randy_Cox I agree. I was just making a point in reality. But, if you want to fine tune with the gas mix, with a great oil, I would stay between 50:1 and 30:1. That is quite a bit of adjustment for jetting overall, but i jet for 32:1, and just finished my YZ 250 today. I ended up going more lean for every jet. Pilot, leaner needle (N3CW), and still at the top groove, the leaner power jet (I don't care for power jets, and don't think they are needed, and just complicate things). and last will be a 175 from the stock 178 main jet. It was the most rich bike stock I ever had by far, and I raised the compression first, (now running 100 octane),, which did lean it some. MXA said it was jetted very well. I guess the kids don't talk with Jody.
If he did not switch back and forth with oxygenated fuel, (just stayed with alky free race fuel of the octanes he needs), he probably would not have much, if anything, for jetting changes. I never ran oxygenated fuel. But just the name says,---"change/richen your jetting', to me. :)
Just stick with the c12
Hard to beat that's for sure
Just run AV gas.
Yall are allowed to have bikes there now?..Hell I thought yall voted liberal and got rid of fun stuff?😳😳😳😳🤣🤣🤣
Someone's always got to bring politics into play 😂.
@@GregHitchko Just noticing the oddness from the strange Left coast. 😉🇺🇸🏴🤠👍🤷♂️
@@Workerbee-zy5nx so true, I try not to think about it. Luckily in terms of that I don't live there 😂 lol
@@GregHitchko Glory be, I hears y'all, yes I own a 89 cr250 with the pro circuit pipe and muffler, and I did a little local motocross on my long gone 84 Cr500r..Trump 2024, keep petrol power 4ever.🤠🇺🇸👍🍻
Best things about California. We make twice as much as other states, our houses are worth twice as much, and we can still ride any dirt bike we want since we sell out of state OHV stickers. Only thing that costs more here is the gas, which is right at 5$. Bikes, cars, and food cost the same as other states 😂. Oh yeah and pro circuit and alot of the big name motocross companies reside here.
Tighten your chain
It's about time someone noticed 😂
really really cool video man!
Thanks man! It was a rad time 💨💨