HELLO, 50 years ago I was a mechanic for Honda.and I discovered that my Wife's Kenmore dish washing machine with the powdered Cascade soap did a job so good on washing motorcycle engine parts that they actually looked like new. The wife got over it eventually... Back then a new Gold Wing cost 3 K. The dish washer had a disinfectant cycle that had a heater unit in the bottom of it that heated the water to 180 degrees.... After many uses it did not even leave an oil film inside...and the dishes came out sparking also. It worked on the block halves and every other part even the carbs. I got brave and washed other parts including a 4 speed Muncie transmission out of a Ford 427 Cobra Jet... I was never disappointed. Back in the day we also trimmed the skirts on 2 stroke pistons in the port area to build more crankcase pressure it got so radical that it would blow out the crank seals right out of the cases. We had to peen the cases with a center punch and install the seals with red lock tight to hold them....When we did this we put the seals in first before joining the halves....Our shop had our own racing team and the owners who were man and wife were both West Coast Enduro Champions...They had twin sons that were also racers....I remember when the first water cooled 2 stokes came out and how strange they looked....I think that was 1976? My personal ride was a 1972 Honda CB 750 K. I rode it for over 300 thousand miles until my second wife got pissed off at me and ran over my bike with my Dodge power wagon...I decided to move on to wife #3. Getting a new wife is easy, replacing something that you love is harder.
I worked at a 2 cycle motor shop for a few years when in school and as a second job. What was done on a rebuild always included checking all surfaces for flatness. If it was a motor we had not built the cylinder was cut to ensure the top and bottom were perpendicular to the bore. Pistons were measured for diameter and cylinders were honed and checked with a bore gauge to ensure they were round and not tapered, it was also the way proper piston to bore clearance. I hope she stays together for you, looks like a fun bike, always amazed me how much power a 125 two stroke can make I get running a ball hone through if your putting in a new ring or have it apart to check wear or replace gaskets but once your buying a pile of parts it’s worth the time to go through more throughly.
Your absolutely rite I worked at a machine shop and him saying you can't hone nickesil cylinders is incorrect you have to use the correct hone and honing oil for those cylinders, I build and port chainsaws and all those cylinders are nickesil so
@@larrywarner9314 Yep you just need the correct stones. Just because they call those things a ball "hone" does not make it a hone. There is no way to see what you are doing and ensure you are not honing a taper or "hole" into the bore without an actual honing machine. That is the thing about honing, really circular lapping, is that you can make a very accurate surface with the correct tools and knowledge
Me and my brother were waiting for it to bog out and loose compression the whole time he was riding definitely why it has a hanging idle you would think he would now this after how many bikes he’s had but he thinks it’s too rich and needs less fuel🤔🤔
Looking at the JIS screws for the shift shaft, it is apparent that people are not using the correct heads when tightening them. The US uses Phillips but Japanese bikes use Japanese Industry Standard patterns which are different and when you use a phillips #2 it does not get the full engagement resulting in damaged heads. You can also identify JIS by a dot usually stamped into the head
I recently got me a set of Wera screwdrivers, best screwdrivers I've ever used. There JIS but also play very well with all other screws. It's nice to have the bolster on a screw driver, great for working on old stuck screws.
Wow, I have been working on bikes for many years and am embarrassed to say that I have never known of "JIS" screws, have owned nothing other than Phillips drivers when working on them. I have seen many bikes with stripped out master cylinder cover screws, now I know why! Thanks!
A pressure check on any two stroke will help prevent failure on a new motor. A lot of comments on the lack of a crankshaft seal on here, by doing a pressure check on the motor after the rebuild you will catch mistakes like that. Hope you find that before it blows up again. nice video!
The times you use assembly lube and loctite, clean that lube out of the holes. It won't allow the threadlocker to cure rendering it useless. Same on another video were you got assembly lube on the rtv for case halves..that spot will leak eventually because rtv won't seal to metal with lube on the rtv
BRAVO, you didn't bury it. Love the engine rebuilds, always something to learn. Next we'll learn upgrading, maybe a 550 or 650 engine? You have the patience of Saint. I'd have used the hammer - not in a good way - a lot sooner
The crush washers on the head can be heated with a torch and reused. It's called annealing. It swells them back to like new. Can be done a couple times. I like to lightly sand mine to make grooves as well.
Air screw adjustments are also a good indication of the jetting. General air screw settings are 1.5 turns out. With the bike warmed up and idling, start adjusting the air screw until you achieve the highest RPM. Count the number of turns out and then you will know if your low speed is too large ie 2 or 2.5 turns out or too small, fewer air screw turns. These are just general rules of thumb but a good thing to have in mind. Additionally, if you spray carb cleaner around the sealing areas and you get a increase in revs, you have an air leak in that area. Lastly, it is always best to use copper crush gaskets on the head bolts. It looked like one of those washers was a steel washer.
Good advice, but Joe already knows this. Many carbs come stock tune with 2.5 turns out on the air or fuel screw (depending on it being for a 2 or 4 stroke engine) Your comment got a "like" from me. Peace.
love how you show us all how todo everything you are doing in the process of doing it. favorite youtube channel by far. edit- never knew that grease trick with gaskets before today thank you 🙌🏻
You can accomplish the same thing with gaskets by rubbing in a liberal application of Tri-Flow or a similar product, less messy, I do it on all gaskets and most gaskets can be re-used. Some just should not be used over, like the O-rings in that head and the crush washers, they crush once with no way to reshape them.
Great video joe. Ive been a rm lover for ever. Im 56 years old and had rms all my life. Such a good educational video for us. We thank you with your know how.
I admit I am addicted to watching you effortlessly diagnose and repair these machines. I can only make one suggestion related to a chain coming off a bike you were test riding...can you guess what i am thinking? Hint - its not running shoes. 🙂
Dude I just wanna say I love the videos and vintage bike's. I live n breath all thing's motorcycle. You remind me of myself going through everything, so I enjoy watching and seeing them come back to life keep it up brother 🤘
That Bike Rips Nice Job So My Question is on the Other Piston you Drilled Holes On either Side of that Divider and On this 1 they were in line with the Divider any reason Why ?
38:40 Turn the gas on then lean the bike over to the left until fuel pisses out of the vent lines, tgen pull the choke, give 2-3 slow priming kicks, then kick to start. When you lean the bike over it primes the engine so you kick less and it doesnt lean rev like mad on startup.
The old guy that taught me how to work on 2 strokes and start them properly lol always got on my ass if I didn't lean to start. Hes like why you wanna sit there n kick your ass off when you can prime it and kick it 2 or 3 times and your good lol. Wise old man he was.
I’ve seen people do this and heard it online for years and have never had to do this UNTIL I did a 144 big bore swap on my most recent RM build. The high compression requires 110 fuel and the only thing I can figure is that the fuel evaporates quicker so the fuel in the bowl is super concentrated and causes the high rev and leaning it causes the old fuel to cycle out and new fuel to fill the bowl.
I'll be 70 in a couple months and sure wish i knew about JIS screws in my 20's and since! I always had a hard time getting them out and ruined most of the heads. Love your videos
The rod bearing is gone and thats why there are dings on the piston . The new chrome or newer coatings on cylinders dont get honed. Clean and buff at most or the coating will get wrecked. These videos are really fun to watch.
Thanks for the great vid Im having a hell of a time finding electrical parts for my 91rm 125 .I already bought 2 CDIs off of Ebay that dont work , Where do you get your ignition parts for older bikes
lol I love that he says it’s running great. That bike is screaming. Can’t wait to see if it blows up at the end of this video cause it’s not going to last long.
I think its mostly dependent on if there is an exhaust bridge in the cylinder from my understanding. The instructions to the weisco piston I bought said so at least, and its forged
While I do enjoy fmf pipes, I find their suggested jetting to be off in most cases. I recommend jetting by the pro circuit jetting guide even if you have an fmf pipe.
can the same logic be applied to hgs pipes ? looked high and low for a hgs jetting chart, cannot find one anywhere online, including their website, ive played with my jetting quite a bit and had it pretty decent, but after just doing the top end, i know it will now likely need some adjustment possibly, and would be nice to have something to reference.
@@MYNYDD-MOTO their jetting is a good starting point for any of the bikes with some increased airflow. I would definitely use their specs for hgs exhaust as well
When I put my gaskets on I put a little silicone around the gaskets to keep them from moving when u torque the head down plus incase u need a little extra seal it’ll help but jst a tip I do when fixing my sleds after They overheated
I feel I need to comment that the engine does not sound right . Check all settings are standard in carb . When you were fitting the ignition the left hand crank seal was missing , bike would run but poorly but if you removed ignition cover it would stop and not restart , I have seen this done !
First thing I would have checked would have been if that cylinder had a plated or steel sleeve. I think the cylinder is the problem. It's probably warped and or egg shaped and it just chews up pistons and won't seal. Send the cylinder off and have a sleeve put in it and forget about it. While it's gone replace the crank seals. The high idle is definitely an air leak.
Yo 2vin awesome wort as always, so I’ve just rebuilt a rmz250 put oil in and started straight up, put coolant in and it went straight in the engine 😢 stripped it back down can’t see anything wrong all looks good and help guys 😩👍
It sounds like the old suzuki 125 I use to own. It was a lot of fun. One ring racing piston too. So its a ripper for sure! Its a pretty nice lookng bike.
you can get small brushes in packs of 50 or whatever and use those to paint on your grease, never seize, oil.. onto your gasket surfaces instead of the gasket itself and keep your hands clean. Good to hear the 2 smoke run.
Great vid. Always enjoy learning from you wrench’n on stuff…one thing I do for old gasket mat’l, is use a die grinder with a fine nylon pad & that old mat’l comes right off. Makes a slow tidious job go much quicker
On my yz's I've always used a tach and set idle to 1000rpm, turned idle air in until rpm starts to drop then back out just until max idle is reached and give it an extra 32nd - 16th turn and then reset for 1000rpm idle. Makes it spot on w/no bogging down off ldle.
My Husky liked to be seized a few times before it ran well at high RPM. Just used to wet and dry the scraped areas put it together. After a couple of times it would sound a bit loose when cold, but run reliably well when at racing temps.
Many modern small bore bikes have sub-sizes on the bore and piston. A letter A, B, C, or D is inked on the outside of the cylinder. Make sure you buy the correct piston. Aftermarket pistons usually don’t offer sub-sizes, and sell loose pistons, so I buy OEM.
No, substitute for experience he has excellent knowledge tricky/difficult mechanical issues/details ie drilling holes in the piston, matching reeds, jets to the bike esp exhaust pipe, coil/spark plug issues, cooling/oil leaks ie bad gaskets, inappropriate/bad/inferior parts.
He didn’t show it on video, but when putting the piston pin circling in, always put a rag under the piston in case the clips flys off and down the crankcase during attempt. Engine out yea you can try and flip it upside down. In the frame not as easy.
Old school dirt bike rider here. Is that a bridged exhaust port? Does your replacement piston come with holes in piston skirt to allow lubricant to center of exhaust port ? I found out that factory pistons do come that way but aftermarket ones diner and you have to drill small holes to allow this
Like your videos but 1, new top end do 3 to 5 heat cycles, 1st low low revs 10 mins idling, 1 min from end do quater revs, rest 30 to 60 mins, repeat 2nd time idling 5 mins then 5 mins quarter revs last min half revs. Then repeat 3rd time round idle 5 mins, rev half throttle 1min on 1 min off. 2, before riding any bike but especially new piston, Start up when ready pull away take it easy 10 mins only half throttle no high revs, once cylinder is hot after 10 mins engine heats up hotter than bike on idle, then after 10 mins do the quick high rev riding in power band but only hold it briefly, after 15mins hold it few seconds not too long, 2 or 3 seconds, then ride easy like this for 30mins until 1hr passes by on new piston, dont ride in power band alot while bedding everything in. 3, after 1 hr on piston after 30 mins ride after 3 heat cycles minimum 5 better, then hold the power band for abit longer few seconds not riding in power band over seconds. Then then have 10 min rest or coffee break, then warm up easy for 10 to 15mins, similar processes, then after that Start riding it like you did when you first started riding the bike in this video. You dont want score piston revving too high while cylinder not hot enough yet so no cold or hot seizures, or worse. Always run 32to1 more oil better, slightly lean out carb from stock settings, so 1 needle clip leaner, 1 jet size smaller on small jet so idles lower quieter, air mixture screw may only need be 1 to 1.25 1.5 turns out max my 2000 cr250 1.25 turns out and still runs rich but better than stock, then bike should instantly rev from idle no bogging to full revs. Have fun and keep life of your bike going strong for longer. Once done all this, every ride after 10 to 15mins warmer, longer if very cold outside before riding its like you stolen it. Then if you ride high revs alot chage piston at 20 hrs otherwise 30 hrs check it, may last 40hrs all depends how long you ride in high revs, if constantly in high revs like in sand or wet mud no more than 20hrs, some trial riders i.e can get 100hrs out of piston as not high revs enough but can then afford run less oil in tank. Lube up all parts, put 30 mmm or each sea foam, mmo, and zx1 friction eliminator in once in a while to, zx1 bonds at 60c so less friction on moving parts. If storing bike through winter, sea foam in tank not much, then Start up 5mins on idle once every month or 2, after few months mix some fresh fuel in, then run bike 5mins then after 5mins again only quarter throttle revs as engine not hot full revs and will score piston. Show more love to engines. DON'T Start up any engine then rev shit out of it, or ride it high revs as you will not get best life out of parts. Remember it wont take too long being patient before you race ride it, have fun pal good luck
When you moved the handlebars the engine revs increased. I thought, " that aint right ". I was happy to see you fixed that. Nothing like a stuck throttle when heading towards a line of trees. That bike sure is burbling though. Jetting was off I reckon. Why do people think bigger jets equal more power and no downsides? Maybe they just like cleaning spark plugs all day.
I love his content don't get me wrong but he is a prime example that engines don't need to be perfect to run. There is a pretty big margin for sloppiness when it comes to engine building and I'm sure it surprises some people who watch his videos. lol
@@Fox250R right run some old benol from klotz at 32;1 and youd better have some spare plugs or be wide open constantly lol love klotz and some groovy grape upper cylinder lube/fuel fragrance by power plus.
There's something about the sound of a performance two-stroke engine getting revved, if you can get it, put some Castrol R in the petrol as well, the exhaust smell is amazing
You should hang a can of premix up above the bike and have a hose with a valve on it so you can test these bikes without having to put the gas tank back on. It'll make it much easier to see everything while you're still troubleshooting
All that work this kid does on this bike and he doesn't know how to break it in no wonder why they blow up He's running it at full he's got a pinned it's crazy to even watch it hurts my head I can't imagine that this kid doesn't know how to break a bike in unbelievable😂
We used to relieve exhaust port bridge a few thousandth s to allow for expansion on air cooled YZ and RMs before water cooled bikes. Looks like oil mix to lean and or main jet to lean to ruin rod bearings . RMs held up better than others . I worked at dealership in NY. Love 125 class . Fastest class.
I haven't done one of these in years, but the wrist pin just sits in there floating around with no c-clips? Its not a pressed pin, so what keeps it from moving and rubbing the sides of the cylinder? Is this something new?
Id say the last guy had a bad premix oil and not enough of it im 44 now and have rode my whole life and i only ever used either caster 927 or honda hp2 never had a issue or foulded plug with either and i love the smell of the caster oil lol
When lapping something (head) on a glass surface with abrasive or wet/dry paper, should use figure-of-eight motion, not circular. So as to change leading edge on the lapped part, avoid removing more material on one edge.
You always do a great job on your videos, One thing I have to say is, all that assembly lube in the threads, Loctite will not set if any oils are in the threads.. JS?! 😕
you can drill a cup in every cracks end so its cant go forward,then take a grinder and grind the crack a u shabe so deep at you cant see any cracks lines, then you can use braising rod and braising flux or just use tic weld to fix all.
I once had an older RD500 4 cyl v-4 2-stroke and also ran into the issue with coolant coming from the upper head bolts. When I researched it it turned out to be because I had put the wrong nuts on. There were supposed to be domed nuts and not regular ones. With domed nuts the coolant stayed in the head. Very weird stuff.
HELLO, 50 years ago I was a mechanic for Honda.and I discovered that my Wife's Kenmore dish washing machine with the powdered Cascade soap did a job so good on washing motorcycle engine parts that they actually looked like new. The wife got over it eventually... Back then a new Gold Wing cost 3 K. The dish washer had a disinfectant cycle that had a heater unit in the bottom of it that heated the water to 180 degrees.... After many uses it did not even leave an oil film inside...and the dishes came out sparking also. It worked on the block halves and every other part even the carbs. I got brave and washed other parts including a 4 speed Muncie transmission out of a Ford 427 Cobra Jet... I was never disappointed. Back in the day we also trimmed the skirts on 2 stroke pistons in the port area to build more crankcase pressure it got so radical that it would blow out the crank seals right out of the cases. We had to peen the cases with a center punch and install the seals with red lock tight to hold them....When we did this we put the seals in first before joining the halves....Our shop had our own racing team and the owners who were man and wife were both West Coast Enduro Champions...They had twin sons that were also racers....I remember when the first water cooled 2 stokes came out and how strange they looked....I think that was 1976? My personal ride was a 1972 Honda CB 750 K. I rode it for over 300 thousand miles until my second wife got pissed off at me and ran over my bike with my Dodge power wagon...I decided to move on to wife #3. Getting a new wife is easy, replacing something that you love is harder.
I'm voting this for Best-Grease-Monkey post of the year. It even included ex-wife history. Well done.
I did that 40 years ago. I'd have a countertop dishwasher if I was doing this at home.
😂😂😂😂😂AWESOME!!! Loved every word of that!!
What year was your power wagon?
@@timbarry5080 🤣🤣
Damn man. Every video you put out teaches me something new....I deeply appreciate you sharing your knowledge and your attitude about it. Love it mane!
good thing you mentioned the 2 holes on the piston. i rebuilt my 125 recently and didnt know you had to do that. you just saved my ass!
I wasn't listening, what did he say?
if you buy a proper piston & not a cheap o you dont have to do it because it will come with the holes in it already
@@BoxingLegends2024 yea i took the pipe off and looked in it and it already had the hole in it, its a wiseco piston
I worked at a 2 cycle motor shop for a few years when in school and as a second job. What was done on a rebuild always included checking all surfaces for flatness. If it was a motor we had not built the cylinder was cut to ensure the top and bottom were perpendicular to the bore. Pistons were measured for diameter and cylinders were honed and checked with a bore gauge to ensure they were round and not tapered, it was also the way proper piston to bore clearance. I hope she stays together for you, looks like a fun bike, always amazed me how much power a 125 two stroke can make
I get running a ball hone through if your putting in a new ring or have it apart to check wear or replace gaskets but once your buying a pile of parts it’s worth the time to go through more throughly.
old guy who grew up on a KX500 here and rode them for 40 years. Listen to this guy and get a feel for overheating.
Well said. I appreciate your attention to detail. I like Joe's style & i do the same. If it looks good, don't mess too much with it unnecessarily...:)
Your absolutely rite I worked at a machine shop and him saying you can't hone nickesil cylinders is incorrect you have to use the correct hone and honing oil for those cylinders, I build and port chainsaws and all those cylinders are nickesil so
@@larrywarner9314 Yep you just need the correct stones. Just because they call those things a ball "hone" does not make it a hone. There is no way to see what you are doing and ensure you are not honing a taper or "hole" into the bore without an actual honing machine. That is the thing about honing, really circular lapping, is that you can make a very accurate surface with the correct tools and knowledge
2 strokes are not treated the same as 4 strokes.
Back to the old tried and true dirt bikes. Another great video. Engine teardown, learning moments. Keep up with hard work and a variety
😅😅😢😢😢😢
This guy is the biggest hack going and you think he's good that's a joke
Stator went on with no crank seal installed 😮that’s going to be a problem. Hope you catch that before you ship it out the door. 15:33.
Probably why it’s revving out and going lean when idling.
Holy Moly!! Good catch. He better address this in a later video lol I am interested in what his reaction will be
Up
Yea I saw it too but some stuff he completely leaves out of the vid like putting the piston pin cir-clips in. He should at least say he did it.
Me and my brother were waiting for it to bog out and loose compression the whole time he was riding definitely why it has a hanging idle you would think he would now this after how many bikes he’s had but he thinks it’s too rich and needs less fuel🤔🤔
Looking at the JIS screws for the shift shaft, it is apparent that people are not using the correct heads when tightening them. The US uses Phillips but Japanese bikes use Japanese Industry Standard patterns which are different and when you use a phillips #2 it does not get the full engagement resulting in damaged heads. You can also identify JIS by a dot usually stamped into the head
I learned about the JIS screws the hard way 😂
Same here😂 now I have a set of JIS tools. Makes life waay easier
I recently got me a set of Wera screwdrivers, best screwdrivers I've ever used. There JIS but also play very well with all other screws.
It's nice to have the bolster on a screw driver, great for working on old stuck screws.
Wow, I have been working on bikes for many years and am embarrassed to say that I have never known of "JIS" screws, have owned nothing other than Phillips drivers when working on them. I have seen many bikes with stripped out master cylinder cover screws, now I know why! Thanks!
So far i see five things you did not check or do that could be catastrophic
A pressure check on any two stroke will help prevent failure on a new motor. A lot of comments on the lack of a crankshaft seal on here, by doing a pressure check on the motor after the rebuild you will catch mistakes like that. Hope you find that before it blows up again. nice video!
The times you use assembly lube and loctite, clean that lube out of the holes. It won't allow the threadlocker to cure rendering it useless. Same on another video were you got assembly lube on the rtv for case halves..that spot will leak eventually because rtv won't seal to metal with lube on the rtv
Great job on this one. This is why I watch your channel. Very interesting and thorough. Thanks again for your time today and enjoy your weekend.
BRAVO, you didn't bury it. Love the engine rebuilds, always something to learn. Next we'll learn upgrading, maybe a 550 or 650 engine?
You have the patience of Saint. I'd have used the hammer - not in a good way - a lot sooner
The crush washers on the head can be heated with a torch and reused. It's called annealing. It swells them back to like new. Can be done a couple times. I like to lightly sand mine to make grooves as well.
Air screw adjustments are also a good indication of the jetting. General air screw settings are 1.5 turns out. With the bike warmed up and idling, start adjusting the air screw until you achieve the highest RPM. Count the number of turns out and then you will know if your low speed is too large ie 2 or 2.5 turns out or too small, fewer air screw turns. These are just general rules of thumb but a good thing to have in mind. Additionally, if you spray carb cleaner around the sealing areas and you get a increase in revs, you have an air leak in that area. Lastly, it is always best to use copper crush gaskets on the head bolts. It looked like one of those washers was a steel washer.
Good advice, but Joe already knows this. Many carbs come stock tune with 2.5 turns out on the air or fuel screw (depending on it being for a 2 or 4 stroke engine) Your comment got a "like" from me. Peace.
Is this for 2 strokes only? I've always been told 2.5 turns was perfect
@@forzanoobboth 2 stroke and 4 stroke all my bikes are 2.5
@@forzanoob , same thing I've known since first turning a wrench at East Coast Kawasaki in 1979.
@@forzanoob only 2 strokes, 4 strokes are normally about 2 an a half turns out
Dremel with the scotch brite pads are awesome gasket removers after razor blades. Want it clean for no leaks.
love how you show us all how todo everything you are doing in the process of doing it. favorite youtube channel by far. edit- never knew that grease trick with gaskets before today thank you 🙌🏻
You can accomplish the same thing with gaskets by rubbing in a liberal application of Tri-Flow or a similar product, less messy, I do it on all gaskets and most gaskets can be re-used. Some just should not be used over, like the O-rings in that head and the crush washers, they crush once with no way to reshape them.
Great video joe. Ive been a rm lover for ever. Im 56 years old and had rms all my life. Such a good educational video for us. We thank you with your know how.
I am 55 years of age and also love the RM bikes i have owed over 30 of them i now have a mint 1982 rm 250 and a 2023 rmz 450 .
I admit I am addicted to watching you effortlessly diagnose and repair these machines. I can only make one suggestion related to a chain coming off a bike you were test riding...can you guess what i am thinking? Hint - its not running shoes. 🙂
im pretty much a amateur rider so 125s are about my speed, some of the more fun times in my life was on a rm 125. good detailed build man👍
Dude I just wanna say I love the videos and vintage bike's. I live n breath all thing's motorcycle. You remind me of myself going through everything, so I enjoy watching and seeing them come back to life keep it up brother 🤘
Please dont say " vintage". That makes me feel really old. Wait.... I am. Never mind.
That Bike Rips Nice Job So My Question is on the Other Piston you Drilled Holes On either Side of that Divider and On this 1 they were in line with the Divider any reason Why ?
The inner clutch hub rides directly on the needle bearing? I thought there was a washer in between them?
38:40 Turn the gas on then lean the bike over to the left until fuel pisses out of the vent lines, tgen pull the choke, give 2-3 slow priming kicks, then kick to start.
When you lean the bike over it primes the engine so you kick less and it doesnt lean rev like mad on startup.
The old guy that taught me how to work on 2 strokes and start them properly lol always got on my ass if I didn't lean to start. Hes like why you wanna sit there n kick your ass off when you can prime it and kick it 2 or 3 times and your good lol. Wise old man he was.
I’ve seen people do this and heard it online for years and have never had to do this UNTIL I did a 144 big bore swap on my most recent RM build.
The high compression requires 110 fuel and the only thing I can figure is that the fuel evaporates quicker so the fuel in the bowl is super concentrated and causes the high rev and leaning it causes the old fuel to cycle out and new fuel to fill the bowl.
That bike is a beauty! Sounds great too. I think Suzuki has the best sounding bikes
laughs in Honda...
I'll be 70 in a couple months and sure wish i knew about JIS screws in my 20's and since! I always had a hard time getting them out and ruined most of the heads.
Love your videos
The rod bearing is gone and thats why there are dings on the piston . The new chrome or newer coatings on cylinders dont get honed. Clean and buff at most or the coating will get wrecked. These videos are really fun to watch.
Thanks for the great vid Im having a hell of a time finding electrical parts for my 91rm 125 .I already bought 2 CDIs off of Ebay that dont work , Where do you get your ignition parts for older bikes
Did you manage to find a CDI mate?
lol I love that he says it’s running great. That bike is screaming. Can’t wait to see if it blows up at the end of this video cause it’s not going to last long.
Two strokes are supposed to scream... if just to annoy 4 stroke riders.
You cracked me up when you said the previous owner had the motor lock up on him then you said...."so something happen there" lol
Great bike, love the Suzuki 2 strokes... that crisp popping sound is unique. Great vid
I was gone say I’d resurface the head then you ended up doing it anyway not a big setback though! Great job on the rebuild and video bud.
Nice to see you clean the parts before install ! That's huge !
2:57-“yeah that rod feels good in there”😂
😩
I thought you only had to drill the lube holes in a forged piston, and I’m pretty sure pro x does cast pistons. Could be wrong tho
I think its mostly dependent on if there is an exhaust bridge in the cylinder from my understanding. The instructions to the weisco piston I bought said so at least, and its forged
While I do enjoy fmf pipes, I find their suggested jetting to be off in most cases. I recommend jetting by the pro circuit jetting guide even if you have an fmf pipe.
can the same logic be applied to hgs pipes ? looked high and low for a hgs jetting chart, cannot find one anywhere online, including their website, ive played with my jetting quite a bit and had it pretty decent, but after just doing the top end, i know it will now likely need some adjustment possibly, and would be nice to have something to reference.
@@MYNYDD-MOTO is your bike an 01 rm250 as well?
@@shanewilliams8768 07 rm 125
@@MYNYDD-MOTO their jetting is a good starting point for any of the bikes with some increased airflow. I would definitely use their specs for hgs exhaust as well
@@shanewilliams8768 will give it a try thank you 🏁
When I put my gaskets on I put a little silicone around the gaskets to keep them from moving when u torque the head down plus incase u need a little extra seal it’ll help but jst a tip I do when fixing my sleds after They overheated
I feel I need to comment that the engine does not sound right . Check all settings are standard in carb . When you were fitting the ignition the left hand crank seal was missing , bike would run but poorly but if you removed ignition cover it would stop and not restart , I have seen this done !
Pro tip: grease up the mating surfaces with a small brush rather getting your hands covered in grease by greasing the gasket.
Wow, just started watching so I'm assuming you blew it up too? Idk yet but can't wait to see, thanks for the great content lately!
Nope
@@tedkowal1 Not yet lol. Hopefully he catches the lack of a crank seal on the stator side..
He didn’t blow it up. He purchased it like that.
Good morning everyone!
Good morning
Goodnight from Australia
Morning
Hello from Nashville, TN! Morning!
It's not morning brother its afternoon here in the UK!🇬🇧
that idle still sounds way to high
The idle is still too high.
He did a good job of editing that out so you couldn't hear it.
he never put the crank seal on at 15:33 Air leak "high idle"
It wouldnt start that easy without a seal@@BoxingLegends2024
First thing I would have checked would have been if that cylinder had a plated or steel sleeve. I think the cylinder is the problem. It's probably warped and or egg shaped and it just chews up pistons and won't seal. Send the cylinder off and have a sleeve put in it and forget about it. While it's gone replace the crank seals. The high idle is definitely an air leak.
If you watch closely at 15:33 in the video the stator goes on without the crank seal underneath. Probably reason for the high idle
Yo 2vin awesome wort as always, so I’ve just rebuilt a rmz250 put oil in and started straight up, put coolant in and it went straight in the engine 😢 stripped it back down can’t see anything wrong all looks good and help guys 😩👍
It sounds like the old suzuki 125 I use to own. It was a lot of fun. One ring racing piston too. So its a ripper for sure! Its a pretty nice lookng bike.
you can get small brushes in packs of 50 or whatever and use those to paint on your grease, never seize, oil.. onto your gasket surfaces instead of the gasket itself and keep your hands clean. Good to hear the 2 smoke run.
Great vid. Always enjoy learning from you wrench’n on stuff…one thing I do for old gasket mat’l, is use a die grinder with a fine nylon pad & that old mat’l comes right off. Makes a slow tidious job go much quicker
TYVM allways well made and fun to watch (from Quebec Canada )
I’ve just subscribed
With all your videos. I feel pretty confident when buying a motocross bike for me and my boy for the first time thanks buddy👍
On my yz's I've always used a tach and set idle to 1000rpm, turned idle air in until rpm starts to drop then back out just until max idle is reached and give it an extra 32nd - 16th turn and then reset for 1000rpm idle. Makes it spot on w/no bogging down off ldle.
I have a hot rods crank in my cr125, it’s ran good for the last year since I installed it. Just double check the trueness of cranks before install
My Husky liked to be seized a few times before it ran well at high RPM. Just used to wet and dry the scraped areas put it together. After a couple of times it would sound a bit loose when cold, but run reliably well when at racing temps.
🤯🤯🤯🤯🤯🤯🤯🤯
@@stmboat
It's still racing. Twin shock 1980 CR250. Goes well.
I had an 87 XC250. It was a powerhouse.@@isickofit
Many modern small bore bikes have sub-sizes on the bore and piston. A letter A, B, C, or D is inked on the outside of the cylinder. Make sure you buy the correct piston. Aftermarket pistons usually don’t offer sub-sizes, and sell loose pistons, so I buy OEM.
Did i miss you putting the circlips in the little end bearings ?
Did you replace the one time use crush washers on the head studs? I'll bet that's why coolant is leaking out!
Love your videos man... keep them coming!!!!
When you hone a cylinder, do you chamfer the edges of the port so the rings don't get caught?
Sold my 250f an got an 01 just like this did a restyle on it out the gate I love it so much lighter and plenty of power
No, substitute for experience he has excellent knowledge tricky/difficult mechanical issues/details ie drilling holes in the piston, matching reeds, jets to the bike esp exhaust pipe, coil/spark plug issues, cooling/oil leaks ie bad gaskets, inappropriate/bad/inferior parts.
Yep the green scotch Brite would on nikisil,I have seen people use a ball hone and it works
Cool! Take it out for a good rip now! Great video, thanks Joe!
@2vintage What kind of 2 stroke oil do you use? Amsoil Dominator @ 40 to 1?
I had coolant coming thru stud as well on my LT..had it decked etc and solved the issue.. fresh washers etc
He didn’t show it on video, but when putting the piston pin circling in, always put a rag under the piston in case the clips flys off and down the crankcase during attempt. Engine out yea you can try and flip it upside down. In the frame not as easy.
Old school dirt bike rider here. Is that a bridged exhaust port? Does your replacement piston come with holes in piston skirt to allow lubricant to center of exhaust port ? I found out that factory pistons do come that way but aftermarket ones diner and you have to drill small holes to allow this
Hah sorry just saw text of video about this!!
Like your videos but
1, new top end do 3 to 5 heat cycles, 1st low low revs 10 mins idling, 1 min from end do quater revs, rest 30 to 60 mins, repeat 2nd time idling 5 mins then 5 mins quarter revs last min half revs. Then repeat 3rd time round idle 5 mins, rev half throttle 1min on 1 min off.
2, before riding any bike but especially new piston, Start up when ready pull away take it easy 10 mins only half throttle no high revs, once cylinder is hot after 10 mins engine heats up hotter than bike on idle, then after 10 mins do the quick high rev riding in power band but only hold it briefly, after 15mins hold it few seconds not too long, 2 or 3 seconds, then ride easy like this for 30mins until 1hr passes by on new piston, dont ride in power band alot while bedding everything in.
3, after 1 hr on piston after 30 mins ride after 3 heat cycles minimum 5 better, then hold the power band for abit longer few seconds not riding in power band over seconds.
Then then have 10 min rest or coffee break, then warm up easy for 10 to 15mins, similar processes, then after that Start riding it like you did when you first started riding the bike in this video.
You dont want score piston revving too high while cylinder not hot enough yet so no cold or hot seizures, or worse.
Always run 32to1 more oil better, slightly lean out carb from stock settings, so 1 needle clip leaner, 1 jet size smaller on small jet so idles lower quieter, air mixture screw may only need be 1 to 1.25 1.5 turns out max my 2000 cr250 1.25 turns out and still runs rich but better than stock, then bike should instantly rev from idle no bogging to full revs.
Have fun and keep life of your bike going strong for longer.
Once done all this, every ride after 10 to 15mins warmer, longer if very cold outside before riding its like you stolen it.
Then if you ride high revs alot chage piston at 20 hrs otherwise 30 hrs check it, may last 40hrs all depends how long you ride in high revs, if constantly in high revs like in sand or wet mud no more than 20hrs, some trial riders i.e can get 100hrs out of piston as not high revs enough but can then afford run less oil in tank. Lube up all parts, put 30 mmm or each sea foam, mmo, and zx1 friction eliminator in once in a while to, zx1 bonds at 60c so less friction on moving parts.
If storing bike through winter, sea foam in tank not much, then Start up 5mins on idle once every month or 2, after few months mix some fresh fuel in, then run bike 5mins then after 5mins again only quarter throttle revs as engine not hot full revs and will score piston.
Show more love to engines.
DON'T Start up any engine then rev shit out of it, or ride it high revs as you will not get best life out of parts.
Remember it wont take too long being patient before you race ride it, have fun pal good luck
When you moved the handlebars the engine revs increased. I thought, " that aint right ". I was happy to see you fixed that. Nothing like a stuck throttle when heading towards a line of trees. That bike sure is burbling though. Jetting was off I reckon. Why do people think bigger jets equal more power and no downsides? Maybe they just like cleaning spark plugs all day.
Man, those birds in the background are going crazy :D lol
I love his content don't get me wrong but he is a prime example that engines don't need to be perfect to run. There is a pretty big margin for sloppiness when it comes to engine building and I'm sure it surprises some people who watch his videos. lol
Personally I think 42:1 is way to lean especially for a fresh rebuild. 28:1 is good for a fresh rebuild and 32:1 for regular riding.
Haha run good oil you can run 50-1 and be just fine.
@@Fox250R not sure about that I would still run 32:1 no matter the oil brand or cc’s
@@quinnhoddenbagh5456 look up Klotz 2 stroke oil
@@Fox250R right run some old benol from klotz at 32;1 and youd better have some spare plugs or be wide open constantly lol love klotz and some groovy grape upper cylinder lube/fuel fragrance by power plus.
Sounds like it's starving for fuel revving it's tits off😅
Awsome video joe! Great job as per usual
Good lad that sounds so so nice
Keep up the good work love your video that you make
From the UK
There's something about the sound of a performance two-stroke engine getting revved, if you can get it, put some Castrol R in the petrol as well, the exhaust smell is amazing
Love that smell. takes me back to my Teens.
You should hang a can of premix up above the bike and have a hose with a valve on it so you can test these bikes without having to put the gas tank back on. It'll make it much easier to see everything while you're still troubleshooting
Not knocking joe , but there are ways to prevent blowing up rebuilt 2 sroke engines and ive never seen him pressure test or vac test an engine
33:00 nice beat
Love the videos man but Ya forgot the heat cycles man😂😂
Joe, can you explain how the choke works on a carburetor like that and possibilities of what kind of problems that could happen
Thanks!
It overfuels to compensate for denser air when cold
All that work this kid does on this bike and he doesn't know how to break it in no wonder why they blow up He's running it at full he's got a pinned it's crazy to even watch it hurts my head I can't imagine that this kid doesn't know how to break a bike in unbelievable😂
Glad I’m not the only one who calls out his mistakes lol. His mechanic work is comical because usually it’s all incorrect
Meh.... you don't break in a motocross bike. They aren't expected to last even one whole season. 5 minutes at lower revs and then send it.
We used to relieve exhaust port bridge a few thousandth s to allow for expansion on air cooled YZ and RMs before water cooled bikes.
Looks like oil mix to lean and or main jet to lean to ruin rod bearings .
RMs held up better than others .
I worked at dealership in NY.
Love 125 class .
Fastest class.
Get a cricut machine and sheets of gasket material. I cut all my own gaskets in the shop 😁
Did you ever do an update video on that Niche big bore kit in that yellow 400ex? Just wondering how long it held up?
I had a few CR250's and had excellent results from running really good gas and Klotz Beanoil. Never ever had issues
I haven't done one of these in years, but the wrist pin just sits in there floating around with no c-clips? Its not a pressed pin, so what keeps it from moving and rubbing the sides of the cylinder? Is this something new?
Whatcha know, Joe..lool Don't feel bad. I had a similar experience with a 1978 YZ250. Wish I had it to diagnose now. Been a long time.
Id say the last guy had a bad premix oil and not enough of it im 44 now and have rode my whole life and i only ever used either caster 927 or honda hp2 never had a issue or foulded plug with either and i love the smell of the caster oil lol
52:20 It sounds like it is lean to me, hear at 47:25 how it is slow to back down to idle.
Some top notch break in procedures you used..lol
if rev the piss out of it was a person
meh.. it's a racing bike. It's only supposed to last one season. No-one breaks them in.
If u put one aide of the circlip on 1st it makes it way easier on the wrist pin
When lapping something (head) on a glass surface with abrasive or wet/dry paper, should use figure-of-eight motion, not circular. So as to change leading edge on the lapped part, avoid removing more material on one edge.
Nice case.. great job finding that, they suck to find. Never to much when it comes to pre lube.
too much
Tare apart the carb to check all jet sizes are correct.maybe a wrong main or needle?
You always do a great job on your videos, One thing I have to say is, all that assembly lube in the threads, Loctite will not set if any oils are in the threads.. JS?! 😕
You may have to put sealant in the stud holes. Take studs out and sealant and then re install
This is so profound to me. I never would have thought of it.
you can drill a cup in every cracks end so its cant go forward,then take a grinder and grind the crack a u shabe so deep at you cant see any cracks lines, then you can use braising rod and braising flux or just use tic weld to fix all.
And better watch that high idle after you rebuild one that will cold seize that piston
Man I just love the sound of this bike. It brings back memories
the case area where the rod goes cracks on them little pieces chip off & that's what makes the piston lock up used to happen on my RM125 1999 too
Probably whats in piston crown, rod bearing chunks, seen it before but they usually tear up a lot of crap to.nice bike
I once had an older RD500 4 cyl v-4 2-stroke and also ran into the issue with coolant coming from the upper head bolts. When I researched it it turned out to be because I had put the wrong nuts on. There were supposed to be domed nuts and not regular ones. With domed nuts the coolant stayed in the head. Very weird stuff.
Is the head/ barrel warped?
I drilled an extra hole for my bridge port in my 77 RM. 125....piston.