Any procedures to get rid of that ticking sound on my 2018 Kx85?? It sounds like it is coming from the powervalve area!! And I am going to advance my timing on my 1998 Kx80 that was bored to 100cc's w port & head mods by Eric Gorr, he did a great job but his customer service was awful. I got all the nice support mods too, like FMF gold series Fatty pipe/w powercore2 shorty, Boyesen Rad valve, Complete Hinson clutch system, Mishimoto oversized radiator, & just ordered the Boyesen power X-wing for the keihin Pwk 28 I am swapping over from the current keihin Pe26, I am using my Pwk off my 2018 kx85 to see how she likes it before I buy a new one any info you could help me out w would be awesome
Thank you for the education! It’s nice to have someone of such knowledge and worth to take the time to explain the reasons behind why they do what they do! To see the gains after is priceless. Thank you!
Hi from Australia. This was fascinating for me. I'm a motorcycle mechanic, but i don't get the chance to faff about with performance, just servicing and repairs. Thanks for providing av great education. I'm going need with some of this stuff on personal bikes in future and see where i can get to with it 😂
THIS is a great video. I just tore down a 87 lt250r. Cut head .025”, raised the exhaust ports about 1mm and adding a 38mm carb. I had not thought about adding timing but I will now do that!
I was pleasantly surprised to see you use the clutch pull and blip technique after pull runs. More important as the capacity of the bike increases. Well done
I already wanted to send you my kx 112 2023 engine so that you can return it to me with a lot of power haha wow you left me crazy greetings from Puerto Rico 🙋♂️
You do need to know your craft, it is well obvious you do know. It is by no means a back yard thing . I can bolt on a couple things change piston and rings .But to venture for horsepower not my thing Those Championships don't come easy and these bikes must stay together on race day ,they get a lot of punishment . Thank you enjoyable on any kind of bike mods to watch It is never enough watching time.Thank you
How much will racegas add to to the peak, and could you push it even further with ignition, and last question STIC is not available for superminis yet if i am correct? Cool video again Derek, these are stuff everyone wants to see. 👍🏼
generally fuel doesnt add power - but it can allow changes to the engine that can add power. adding igntion past optimum point will just loose power and rpm no stic - sorry
There are many videos testing different fuels on a million different engines (cars, boats, bikes, etc). Stick with what OEM recommends as far as octane. But what you often get from buying race fuel is better consistency and overall quality of fuel, or specific fuel that is legal for particular racing orgnizations. But as far as expecting crazy increases in power - not so much. Been there done that. People who make crazy claims that "race fuel" (which is a very broad term considering there are tons of different "Race fuel" types) making far more power are dilusional. Or the jetting is better which a particular fuel - and that is that.
Nice man , learned A LOT watching you're vid's ... that's insane !!!! thx for that . Using and tuning myself with HPI complete ignitions , but with the stock curves , youre video on that topic was great . Thinking on getting a reprogrammable CDI from HPI . Tuning myself 70cc and 80cc racebikes for 20 years, entering a new level just from you're videos . Looking for that next video on the phatheads and if you could have fixed the overrev problems ... cause that's where i'm stuck on my bike . Was thinking of buying another exhaust to get it hotter like you mentioned ... or maybe learning some cheaper technics from you 😄. Love to see that next video , can't find on the ytbchannel ....
Great stuff...apologies if this has been answered already, but didn't hear it in the video and didn't see it scrolling through comments...were you running pump gas after cutting the head 0.15, if so what octane rating? Your series on the 112 is of particular interest to me as I just moved my oldest up to it. We are xc racers and I was very intrigued by the increase in low/mid and could care less about the earlier sign off. I appreciate your work!
@@ehess8845 oems maximize what is possible on pump gas. They own dynos too…and find the limit to what lives on pump gas .15 would be a huge amount of material as well, i think u meant .015 which is still a lot and not suggested for pump fuel
@@HPRaceDevelopment Fat fingers...yes, meant .015. Quick question if you don't mind regarding break-in of a fresh top end...3-4 heat cycles with no load, or heat cycles with load and progressively higher rpm? Or just ride it?
If you are using Foredom porting tools, (CC specialty), Try the small #28 handle with the 1/8th collet, using a 3" long solid carbide burr cutter with a sphere end. (cutting length is like .5-.75"), for the tight work like that transfer port tunnel work. It is small, (can still grab edges though), and long enough to reach, and see what you are doing. :) I have pored a lot of engines by hand. I use a small Tormac CNC mill now, (last 17 years), and just hand finish them. Your probably right on the tunnel texture,---but I do it anyway.
Anything past stock becomes extremely risky. The OEM has already tested it to the limit. How much octane is needed then varies on both power generated and compression ratio etc.
where should i go to learn how to port 2strokes. Im just an old timer who wants to do work for the locals. 1st 2stroke i had was a 1982 yz80j. favorite 2 stroke was lamsons 1991 peak 125 bike. (wish i never sold it) stopped racing in 2000 after i broke my femur. motox is the best sport, if you dont know do it once! its like crack. lol
have you worked on husqvarna wr300 ? i would really like some more power on the top end. tried raising the power valve, and the helped a lot with onset of power. best regards
@@HPRaceDevelopment With older air cooled bikes with larger clearances I would say more oil for sealing but with water cooled modern engines I would think it's not as noticeable if at all by mixing more oil than say 40:1. So my number guess would be, air cooled older bikes 20:1 and modern water cooled bikes 40:1. I'm aware of the 1978 test on the PE250 but times have changed which peaks my curiosity. Please link me to a video of a modern bike test related to this. Your before and after comparison videos are gems!
@@TepcoCycleRepair It's been our experience with synthetics around 32:1 is best, especially on 85cc and 125 cc for power. Longevity wise 28:1 does wonders for 85ccs and superminis. On castor down to 20:1 usually most hp by a tiny bit over 32:1 but both by a good margin over 50:1. Having said all that - on track, I feel the on off nature of the throttle and rpm, means we have an accumulation of oil in the crankcases off throttle that clears out to whatever mix ratio is under long load. but the short loads it's "over oiled" briefly. So - on track Im slowly convincing myself about 40:1 is right. That said parts will last longer at 32:1 for sure.
The first thing I noticed after you ported the cylinder was way way less smoke. I interpret that as more fuel burned = more efficient = more power! I'm correct am I?
Hi, i really appreciate your videos, very helpful and technical. I just wanted to ask you if is there any book or text, that you may know, which i can rely on to obtain more advanced information about 2 stroke engines
Not really. Modern info is no in any books I know of. There are lots of forums around the world that have some good bits...but it's hard to sort through and find.
I never ran a moto ride on the dyno with a knobby. SLIPPAGE. I always put a street tire on for optimum grip. I can't tell from the vid what you are using on the rear. It almost looks like a knobby. Can you confirm ?
Please tell us the rpm where the peaks occur...Thanks. I need the rpm so I can gear my bike to achieve the absolute highest top speed possible...I want the horsepower peak to occur at the same time my top speed is occurring :).
@hp race development my kx85 2017 with a 100 cylinder and fresh crank seals is running scorching hot on the exhaust and cylinder after quick 3 min ride or just idling?
@@mikedeblanco9186 the squish that runs best… Commonly believed that tighter leads to faster burn, less detonation and more power - but in our testing none of that proves true. Motocross engines are punished and used in a way ive not seen in karting or road racing, and the modern riders are constantly trying to rev them way too much etc etc Ive found best results with what is relatively mild squish tightness - and less than 50 percent bands with usually positive angle - lengthens power and broadens feel
@@HPRaceDevelopment I neglected to reference the fuel It always ran with VP C12 So I can see a larger squish on 93/94 pump fuel. I should have mentioned that.
@@HPRaceDevelopment surely this engine was on its last leg. Didn't the stock Kawi 112 dyno at 25 hp? I was told 32 hp to the wheels by Mitch. I bought one of rider D's back up engines back in 2019...it seemed pretty stout. It also required MRXO2. Everyone's dyno is different.
@@jamessteward6488 brand new bike 0 hours at time of baseline. our dyno at time of this publish reads a lot lower than the pc dyno you quote. Its amazing to me people struggle with this concept - so ill ask you, how is a dyno calibrated?
@@HPRaceDevelopment I wouldn't know,I'm just wondering why.i took notice of the same gear choice on another vid would it matter if you choose first gear ECT.
yeah not sure yet if deto or misfires. when cyl pressure goes up these ig systems are weak. will have a part 3 and touch on that and solutions and such
@@HPRaceDevelopment you could use a gopro and chest mount whilst porting to get a good angle of your work, I appreciate you sharing knowledge of motor building with us i learned a lot so far so thank you and god bless you 🙏
@@adamhollins good idea to see what i see youd need a glasses view but maybe we can work that out that said our goal is to drop knowledge without putting myself out of business :)
Looks like you’re sucking in a lot of fumes there buddy. Maybe you should invent a hose that can be attached to the silencer and vent it outside? Good idea? I think so.
@HPRaceDevelopment That makes perfect sense, Never too old to learn something new, I've had it wrong for year's so thanks for that handy bit of knowledge much appreciated
Not just the head. The Whole motor. A Fully modded kx112 has have the horsepower of a rm85 with a FMF fatty. They are SLOW compared to the new gen 85's
@@bobbyblenio4571 why would i be but hurt? We kicked his kx112s ass to tune of 2 loretta’s supermini titles in 2017. You can be proud of your cheap slow build.
I skip all your 4 stroke videos, but are glued to any 2 stroke content. Keep them coming!
Same here
Any procedures to get rid of that ticking sound on my 2018 Kx85?? It sounds like it is coming from the powervalve area!! And I am going to advance my timing on my 1998 Kx80 that was bored to 100cc's w port & head mods by Eric Gorr, he did a great job but his customer service was awful. I got all the nice support mods too, like FMF gold series Fatty pipe/w powercore2 shorty, Boyesen Rad valve, Complete Hinson clutch system, Mishimoto oversized radiator, & just ordered the Boyesen power X-wing for the keihin Pwk 28 I am swapping over from the current keihin Pe26, I am using my Pwk off my 2018 kx85 to see how she likes it before I buy a new one any info you could help me out w would be awesome
Thank you for the education! It’s nice to have someone of such knowledge and worth to take the time to explain the reasons behind why they do what they do! To see the gains after is priceless. Thank you!
Hi from Australia. This was fascinating for me. I'm a motorcycle mechanic, but i don't get the chance to faff about with performance, just servicing and repairs. Thanks for providing av great education. I'm going need with some of this stuff on personal bikes in future and see where i can get to with it 😂
I can honestly say I agree with 99% of what you said. You have a good modern view on two strokes.
Great stuff dude. Love learning all this stuff.
THIS is a great video. I just tore down a 87 lt250r. Cut head .025”, raised the exhaust ports about 1mm and adding a 38mm carb. I had not thought about adding timing but I will now do that!
I was pleasantly surprised to see you use the clutch pull and blip technique after pull runs. More important as the capacity of the bike increases. Well done
What’s the reason for the blip?
@mikie758in simple term, to keep it lubricated
Amazing video - thanks for shedding some light of the process to refine an mx engine… fascinating!
I have to seriously thank you for making such videos!!
Just found your channel Derek. Great video - thanks for sharing 😊
dude...amazing stuff
I already wanted to send you my kx 112 2023 engine so that you can return it to me with a lot of power haha wow you left me crazy greetings from Puerto Rico 🙋♂️
You do need to know your craft, it is well obvious you do know. It is by no means a back yard thing . I can bolt on a couple things change piston and rings .But to venture for horsepower not my thing Those Championships don't come easy and these bikes must stay together on race day ,they get a lot of punishment . Thank you enjoyable on any kind of bike mods to watch It is never enough watching time.Thank you
Great content Derek, learning alot.
I dont undertand your lenguaje very well but i love this videos! Thanks
That bike sounds real sweet
Great Video Great job 👍
nice work like always,,,,can you help me to show me what i can do to my kx125 1999 pls,,,i use it on street drive
How much will racegas add to to the peak, and could you push it even further with ignition, and last question STIC is not available for superminis yet if i am correct? Cool video again Derek, these are stuff everyone wants to see. 👍🏼
generally fuel doesnt add power - but it can allow changes to the engine that can add power. adding igntion past optimum point will just loose power and rpm
no stic - sorry
@@HPRaceDevelopment Apreciate the input Derek.
There are many videos testing different fuels on a million different engines (cars, boats, bikes, etc). Stick with what OEM recommends as far as octane. But what you often get from buying race fuel is better consistency and overall quality of fuel, or specific fuel that is legal for particular racing orgnizations. But as far as expecting crazy increases in power - not so much. Been there done that. People who make crazy claims that "race fuel" (which is a very broad term considering there are tons of different "Race fuel" types) making far more power are dilusional. Or the jetting is better which a particular fuel - and that is that.
Would love to see you doing this on a CR500. Great video
Nice man , learned A LOT watching you're vid's ... that's insane !!!! thx for that .
Using and tuning myself with HPI complete ignitions , but with the stock curves , youre video on that topic was great .
Thinking on getting a reprogrammable CDI from HPI .
Tuning myself 70cc and 80cc racebikes for 20 years, entering a new level just from you're videos .
Looking for that next video on the phatheads and if you could have fixed the overrev problems ... cause that's where i'm stuck on my bike .
Was thinking of buying another exhaust to get it hotter like you mentioned ... or maybe learning some cheaper technics from you 😄.
Love to see that next video , can't find on the ytbchannel ....
Great stuff...apologies if this has been answered already, but didn't hear it in the video and didn't see it scrolling through comments...were you running pump gas after cutting the head 0.15, if so what octane rating? Your series on the 112 is of particular interest to me as I just moved my oldest up to it. We are xc racers and I was very intrigued by the increase in low/mid and could care less about the earlier sign off. I appreciate your work!
@@ehess8845 oems maximize what is possible on pump gas. They own dynos too…and find the limit to what lives on pump gas
.15 would be a huge amount of material as well, i think u meant .015 which is still a lot and not suggested for pump fuel
@@HPRaceDevelopment Fat fingers...yes, meant .015. Quick question if you don't mind regarding break-in of a fresh top end...3-4 heat cycles with no load, or heat cycles with load and progressively higher rpm? Or just ride it?
If you are using Foredom porting tools, (CC specialty), Try the small #28 handle with the 1/8th collet, using a 3" long solid carbide burr cutter with a sphere end. (cutting length is like .5-.75"), for the tight work like that transfer port tunnel work. It is small, (can still grab edges though), and long enough to reach, and see what you are doing. :)
I have pored a lot of engines by hand. I use a small Tormac CNC mill now, (last 17 years), and just hand finish them.
Your probably right on the tunnel texture,---but I do it anyway.
I have yet to see a cnc be able to do 2t transfers properly.
Great stuff, new sub...at what point of adding compression would it be beneficial to cut in some race fuel?...even 30/70 or 50/50?
Anything past stock becomes extremely risky. The OEM has already tested it to the limit. How much octane is needed then varies on both power generated and compression ratio etc.
So what’s your thoughts on just adding the timing to a stock motor . Or does it require the head work?
it will loose power and rpm
I have a kx112 how much do you charge for this exact work to be done on my bike please lmk cause I need this for the next step in my racing journey
Very informative 👍🇺🇸
Hey man this is absolutely amazing I was just wondering how much to get a kx100 turned by you
depends on the build - 100 mods up to 104 strokers etc
where should i go to learn how to port 2strokes. Im just an old timer who wants to do work for the locals. 1st 2stroke i had was a 1982 yz80j. favorite 2 stroke was lamsons 1991 peak 125 bike. (wish i never sold it) stopped racing in 2000 after i broke my femur. motox is the best sport, if you dont know do it once! its like crack. lol
If I wanna be a client and have work done on my bike by you guys can I have that done I wanna get more power out of my bike and do some real racing
Great video. How much would all of this work cost?
Depends but in this instance around 650 labor
have you worked on husqvarna wr300 ? i would really like some more power on the top end. tried raising the power valve, and the helped a lot with onset of power.
best regards
No sorry
Because you have a Dyno, have you done a video on mix ratios compared to power? Say on a 250 maybe?
yes. What do you think is best if you had to guess
@@HPRaceDevelopment With older air cooled bikes with larger clearances I would say more oil for sealing but with water cooled modern engines I would think it's not as noticeable if at all by mixing more oil than say 40:1. So my number guess would be, air cooled older bikes 20:1 and modern water cooled bikes 40:1. I'm aware of the 1978 test on the PE250 but times have changed which peaks my curiosity. Please link me to a video of a modern bike test related to this. Your before and after comparison videos are gems!
But I would say at any ratio proper jetting is more important for power gain.
@@TepcoCycleRepair It's been our experience with synthetics around 32:1 is best, especially on 85cc and 125 cc for power. Longevity wise 28:1 does wonders for 85ccs and superminis. On castor down to 20:1 usually most hp by a tiny bit over 32:1 but both by a good margin over 50:1. Having said all that - on track, I feel the on off nature of the throttle and rpm, means we have an accumulation of oil in the crankcases off throttle that clears out to whatever mix ratio is under long load. but the short loads it's "over oiled" briefly. So - on track Im slowly convincing myself about 40:1 is right. That said parts will last longer at 32:1 for sure.
The first thing I noticed after you ported the cylinder was way way less smoke. I interpret that as more fuel burned = more efficient = more power! I'm correct am I?
probably was just warmed up better at time of video
Hi, i really appreciate your videos, very helpful and technical. I just wanted to ask you if is there any book or text, that you may know, which i can rely on to obtain more advanced information about 2 stroke engines
Not really. Modern info is no in any books I know of. There are lots of forums around the world that have some good bits...but it's hard to sort through and find.
Part 3 soon?😊
sooner or later. Shops busy!
Great video !
Have you dynoed a 2014+ stock KX100 ?
Does these mods also apply to the KX100 (2014+) ?
All of our mods apply to any bike. Just have to do the right things.
We have dyno lot’s of kx100s. They haven’t changed much since 08
@@HPRaceDevelopment what is the stock HP of the KX100cc ?
@@martinparent145 less than the 112
Yeah he does a Dino video on the KX100 it's really good he does all the best mods
This is great television!
This guy is badass!
Major Gains hey
I never ran a moto ride on the dyno with a knobby. SLIPPAGE. I always put a street tire on for optimum grip. I can't tell from the vid what you are using on the rear. It almost looks like a knobby. Can you confirm ?
@@mikedeblanco9186 not a knobby
Please tell us the rpm where the peaks occur...Thanks. I need the rpm so I can gear my bike to achieve the absolute highest top speed possible...I want the horsepower peak to occur at the same time my top speed is occurring :).
@hp race development my kx85 2017 with a 100 cylinder and fresh crank seals is running scorching hot on the exhaust and cylinder after quick 3 min ride or just idling?
Thanks for the info, sounds like you got some troubleshooting to do
What state are you in.
tx
Is it safe to assume that the top of the transfer ports are the limiting factor in raising the boost port?
not sure what you mean but no? The boost port - has nothing above it to prevent raising it - to the point of the water jackets.
I have squish question. When I was racing AMA PRO with my TZ250 I ran .030-.032" of squish. What squish do you shoot for with your packages ?
@@mikedeblanco9186 the squish that runs best… Commonly believed that tighter leads to faster burn, less detonation and more power - but in our testing none of that proves true. Motocross engines are punished and used in a way ive not seen in karting or road racing, and the modern riders are constantly trying to rev them way too much etc etc
Ive found best results with what is relatively mild squish tightness - and less than 50 percent bands with usually positive angle - lengthens power and broadens feel
@@HPRaceDevelopment I neglected to reference the fuel
It always ran with VP C12
So I can see a larger squish on 93/94 pump fuel. I should have mentioned that.
@@mikedeblanco9186 I dont think fuel is the primary driver to the concepts im laying out.
If I was to advance the timing on a standard kx65 what would it do to the motor performance?
Stock bikes are set up well for their configuration
What kind of hp do you think the Pro Circuit 112 have?
last one tested was 25
@@HPRaceDevelopment surely this engine was on its last leg. Didn't the stock Kawi 112 dyno at 25 hp? I was told 32 hp to the wheels by Mitch. I bought one of rider D's back up engines back in 2019...it seemed pretty stout. It also required MRXO2. Everyone's dyno is different.
@@jamessteward6488 brand new bike 0 hours at time of baseline.
our dyno at time of this publish reads a lot lower than the pc dyno you quote. Its amazing to me people struggle with this concept - so ill ask you, how is a dyno calibrated?
@@HPRaceDevelopment what brand dyno do you use?
@@jamessteward6488 We built it. We will have a whole video serious on the subject you can watch to learn how dynos work and how and why numbers vary
Why put it in third gear during the dinno?. please reply.
what gear should I select in your opinion and why
@@HPRaceDevelopment I wouldn't know,I'm just wondering why.i took notice of the same gear choice on another vid would it matter if you choose first gear ECT.
@@CraigHenry-zq8jz power doesn't change with gear selection, on an inertia dyno LOAD time changes.
@@HPRaceDevelopment thanks for your help.
I heard that "sizzly" harmonics sound at spots...
yeah not sure yet if deto or misfires. when cyl pressure goes up these ig systems are weak. will have a part 3 and touch on that and solutions and such
U didn’t show the porting being done????
? we showed quite a bit of what was done…i cant film and port ….
@@HPRaceDevelopment if ur smart enough to do this work than ur probably smart enough to use a tri pod
@@jonphotos8631 so you want me to show a video of the back of my head?
we have that video up - check my ktm112 video or ktm450 porting video
@@HPRaceDevelopment you could use a gopro and chest mount whilst porting to get a good angle of your work, I appreciate you sharing knowledge of motor building with us i learned a lot so far so thank you and god bless you 🙏
@@adamhollins good idea
to see what i see youd need a glasses view but maybe we can work that out
that said our goal is to drop knowledge without putting myself out of business :)
Are you running 40 to 1?
Nope
Looks like you’re sucking in a lot of fumes there buddy. Maybe you should invent a hose that can be attached to the silencer and vent it outside? Good idea? I think so.
Come build it....
I thought running rich would result in more carbon on the head?
@@Simplyrecovery nope. Lots of fuel washes everything clean. common misconception when people look over parts and see carbon and assume its rich
@HPRaceDevelopment That makes perfect sense, Never too old to learn something new, I've had it wrong for year's so thanks for that handy bit of knowledge much appreciated
Leave the bling porting to Pro Circus, where they only make HP for their bikes and not customers. 2x I've been burned where stock was better.
Almost unbelievable in this day and age that a factory would machine a stock head so badly!
Not just the head. The Whole motor. A Fully modded kx112 has have the horsepower of a rm85 with a FMF fatty. They are SLOW compared to the new gen 85's
Watching Gomer Balls Unbolt that Head made me Cringe…I would Never have him do Any work on my Bike after Watching That🤦♂️
you couldnt afford it
@@HPRaceDevelopment 🤣I take my stuff to Mitch Payton
@@bobbyblenio4571 too bad for you
@@HPRaceDevelopment 🤣🤣🤣…never had Any Problems ….don’t be ButtHurt
@@bobbyblenio4571 why would i be but hurt? We kicked his kx112s ass to tune of 2 loretta’s supermini titles in 2017. You can be proud of your cheap slow build.
How much does the added compression porting cost