Part 10 of the new YZ125 series. We will eventually tear the whole bike down. May take some time waiting on parts and whatnot. Please subscribe and thanks for watching!
I put a new shift shaft in my bike and the Kickstarter gear assembly came out of place and I couldn’t figure it out, you just saved me so mich time and frustration thank you!
I'm 18 and learning about rebuilding dirt bike engines. i bought a kx 250 with a split case and loose parts everywhere. Your videos are the only videos on youtube, that i found, that give me a general idea of where the parts go. your doing a great job, KEEP UP THE GREAT WORK!
Wow! I watched this three time before I tore mine down and thought I was ready and solid. I'm in the middle of going back together and I rewatched this one, and oh man I want to thank you again. That little cap has been puzzling me for days now. But not tomorrow when I do that part. Nope, I'll know right where things go. Thank you
Awesome videos. Simple and straight to the point. Exactly what I needed. Just got my first project bike and waiting for the parts to come in. Thanks for the vids and keep it up
Hi J: Started to take the case apart last night and my son noticed that the crank was spinning free. We traced the problem down to a tight seal on the main shaft. I figure it will just wear a little and then be fine. Anyway the bearings seem to be fine. Thanx for these excellent videos. I learn a lot from them and they aren't full of teenage dribble like so much on RU-vid.
I already took the top end off, removed piston. No free play with the counter shaft at all. I know it's definitely my kick start. Everything else still move around smoothly including gears behind clutch basket but once I put my kick start handle on to see if push down and It doesn't it's siezed definitely. just gonna order a whole new kick start axle, spring etc..
Got everything back together and bike wouldn't start. Traced it down to no spark. Took the plug out and there was water in the piston. Ended up tearing down the top end again. The head "O" ring was deformed and leaking water into the piston. Took cylinder off turned bike over and emptied the water then squirted WD 40 in. Put it back together. Chckd electrical. Stator wasn't showing any resistance. traced it down to broken wire in stator. Started it last night and breaking it in. Thanx
Thanx for these videos. They are great. Really helpful and informative. Been away on business. As far as the crank I can spin it from the flywheel easily with two fingers. When I spin it from the connecting rod it gets caught at BDC. With a little push on the crank with a finger it goes thru BDC. When we took it apart it would spin freely thru BDC all by itself. Don't want to get it together and then have to take it apart again. I will try and make a video but don't know how to post it.
do you wrap the kickstart spring around twice before putting it in the hole or just once just wondering cuz if i dont wrap it around twice my kickstarter won't return fully
Before my question, I just want to thank you for the awesome videos. I am doing the same exact project on a 125 and have watched them all and learned so much. As Im watching the video now, I noticed I set the dust cover on the crankshaft down deeper than you show above. Is this a big deal??
there should be a washer between the idler gear and the top retainer clip you refer to as a c -clamp. its on all the parts lists in the parts schematics under starter. its number 2. WASHER, PLATE 90201-153P0-00
yup when i was putting it back together yesterday it finally decided to fall out and luckly my dad saw were it went and picked it up but we lost the cap at 7:20 spent half hour searching for, so it stopped us right there guess we need to order it, oh well
I’m having trouble with the Kickstarter returning too far. It stops, but if I put a lot of pressure on it it seems to pop forward a little bit more hitting the clutch cover. There’s a little tab and mechanism inside that’s supposed to stop the kick starter from going forward anymore and I think there must be a little issue with that (I just replaced the spring). If I take the kick starter off the spline and rotate it back a little bit and put it back on, it just does the same thing if I put a lot of pressure and pops forward again. Any ideas?
Gr8 video's. Its very helpful. I wanna build a dirt bike. So can u please tell me the all the parts needed to build it and how much time does it take to build it ?????
AUGH! Watching this from part 1 to 10 I am looking and thinking, why did I send it in to rebuild the bottom end when it seized on me? This is not all that complicated as I thought it would be. And there were the re-build kits that had the bottom end ready to install, bearings seals and all. And I sent it in for what? Nothing, What was I thinking!
Lol yup 2 strokes really aren't hard at all if you are patient and attentive.. But make sure you have a manual if you ever decide to dive.. It seems rudimentary but the manual always comes in handy..
At 6:58 Do you not use lock tight? when i took mine off i think it had the blue lock tight in the inside. Also in the inside i noticed a few other bolts had red and blue lock tight also. Do you recomend using the lock tight of will it not need it?
When I put the kickstart back in place I test to see if it works but after about 4 times trying it the spring comes out of place and it just pops out if anyone knows how to fix this lmk please
Hi Johnny: My son and I are rebuilding his Suzuki 1998 RM125. The piston blew up the second day he owned it! I have gone thru and replaced all the bearing in the case. We were getting ready to put the cylinder on when my son said that he didn't like the way that the connecting rod was turning. When we first opened the case it turned easily. Now it gets stuck at the bottom and you need to apply a little spin pressure at the crankshaft to overcome the bottom. Is that normal?
Hi, is it important in which position is drum shifter when Im installing that "gearshift mechanism" ? What that punch mark on shift drum means? Thanks.
Question?? My kick start won't go down anymore, could it just be that I need to replace my spring or could it be anything else that is wrong with it why it won't pull down.
I have a 2001 yz125 and the kickstarter shaft was busted. I ordered a new one and when put it all on the spring comes out after kicking it over a couple times. I still had the case cover off and after that few kicks the spring works its way out of the hole in the case and snaps out. What would cause this?
Normally the spring may not have the right amount of bend in it or it's just worn out. I'd try another spring on eBay since they can be had pretty cheap, I suppose the hole could be worn but doubtful.
Johnny!! I need your help! I have a yz 85 and the kickstarter keeps slipping and not engaging with the gear under it. I felt the gear and it felt very loose to me. Do it need to take the clutch basket off and try and re-seat that gear?? thanks!
Michael Yangmi Yeah, you will probably need to take the entire side cover off. I would say more than likely you need a new bearing. It's a one-way bearing and they tend to wear out.
I'm just trying to get to the spring, my kick start locked up. Will the gaskets tear when I take it apart and will anything fall out that I have to know about
Ok I need some help I replaced the right side crank seal anyway I finally got it all put back together and now the bike doesn't shift it's like it's stuck in first gear
Hey john, i have a question, so my Yamaha YZ125 2004 is just stuck, my piston blew out and cracked on the top, probably from the sparkplug from what the previous owner had put on. Now my kickstart is jammed, there is no compression and i can only move it half way. I opened up the top where i saw my piston, and i took off the top case, so when i try to move the kickstart, you can see the crank trying to turn over but it doesnt want to rotate. Can it be a seized engine where ill have to get a complete top and bottom end rebuild? or can it just be kick starter shaft spring that came out? Im kind of new to this. Help me out thank you!
Patrick Chow Sounds like it need a complete rebuild. Could be the crank bearings, bent crank, pieces in the bottom end, etc.. I doubt it's just the spring.
I have a 99yz 125 i bought for 300 bucks nice bike fires up first second kick every day but when I bought the bike it wouldn't go into gear could stomp n shifter and nothing. Been setting in garage for three days and 2 year old knock it off stand it fell away from him and landed on shifter now its in a gear won't come out clutch won't free rear wheel but I can start it but as soon as I release the clutch it dies. Any thoughts....
Please I need help my yz 80 goes in first and neutral but when I try to Go in second it don't go it acts as if it's in neutral what could be the problem
i got a question about the shifting mechanism... i was riding my bike one day and the shifter just came loose it shifts and everything but the shifter wont come back to its place the a spring came loose or something
johnny can you help please? my kx80 starts revs shifts.... but does not move only revs!! what did I do and how much will it cost? is it the transmission or my entire clutch?
Okay John, I really need your help. The bolt and gear that go on my yz125 2003 crank, has a problem. Like in your video, my gear does not sit flush on the crank and it's spacer. When I tighten it down to about 40 ft pounds it all but seizes the engine. Really stiff. It's like the cranks too short, or the spacer is to long (can't be), or the gap between spacer and barring is to short. The latter is my guess. Because the center of the barring is somewhat pressed onto the crank too, and if that spacer touches the center of the barring, that would stiffen it right up. Any ideas.
I just pulled apart an identical yz125 motor. It's just like yours and the one I'm rebuilding. The crank gear does not sit flush. I wonder if this is a major flaw in design. Because if the enginers would have wanted that spacer sleeve locked to the crank and barring they would have put splines on both to lock them together. The way it is now it looks like a flaw that is garenteed to destroy that seal. The spacer sleeve and crank fit really good and close, but not so close to cause a friction problem. And with a bit of 80w oil between the spacer sleeve and crank it should seal up quiet nice. I can't imagine it using more oil than a burned up seal. I think I'm going to take my spacer sleeve and shortin it a bit on my 72in belt sander. However, in case I'm wrong about this I'm going to use a good used cylinder and head instead of the $350 reconditioned one I got back from Millnium Techknowladgies. So if it blows up, I'll just need a new $140 bottom end off of eBay. I really need to do a video on this too. Yours has really helped a lot.
***** I think so. I have a picture of yours, and I looked at my spare engine, and we put the barring and sleeve on the old crank, and looked at the new engine put together, and they all look the same. That's 4 comparisons. And I took it to the Yamaha dealer and he thinks we have it right. Thank you . I'll get the bike put together and tell you how it runs.
My kickstart goes down and starts my bike but it doesn’t comeback up unless I bring it back up and put it in place. Does that mean the return spring is shot and is it a hard job to replace it
what id the total torque sheet for the rebuild like from cases to topend < if you could trype them up and send it to me would be great or send a link need asapp
I opened it up and its missing that little piece but as of now when i put the kickstart on amd push down with my hand, the gear doesnt pull out to hook on to the other one.it just spins
Javier Cervantes There should be a one way bearing in the gear (only spins one way) and it could be bad. Typically when they are bad they spin both ways.
yea ive done the same thing before and you might be able to get away with doing it without having to take out the clutch basket depending on the bike but its really not bad nor hard to replace it either way
@@Johnnysshop After i pull the side case and clutch assembly, is it as simple as pulling the shift shaft out and sliding the new one in its place? thanks in advance!
i just got it back from the shop i need a new crank piston and i need to repair the cylinder their telling me its going to be more then 1300 dollars to get fixed
Cbc911 Sorry for the delay, MacBook just got back from the shop. Seems pretty steep for a 2 stroke but if they are new OEM parts that could be the case. I'd find some stuff on eBay if I were you.
+Zaanjo If you haven't changed the oil recently I would do that first. It's amazing what cruddy oil can do. If you have already done so, the shifter forks may be getting a bit worn.
***** thanks for the reply man, and yea i changed the oil when i first got it and havent rode for more than 10 mins total on a sidestreet, im guessing it probably is the shift forks
***** it was a light milky color mixed with some blacker oil,and there were a few little chunks of something, idk what it was, but ill change it again, i just used some 2 stroke oil from oriley's, what do you recommend i put back in there?
+Zaanjo You want to use something like 10W30 or something like that. If you're using 2 stroke premix oil, that won't work. Milky sounds like you may have a blown head gasket as well..
Got a question, my 02 yz125 wont go into first gear but it will go through all the gears fine. When I start it and try and put it in gear, it wont go in. Could that be a bad cir clip? Cause the whole motor was just rebuilt.
I tore it back apart and found that the big pin on the back of the drum was not in its hole. Putting it back together the way you did was a lot easier. Thanks
