NS Motocross riders

I know this isn't the perfect place for a tech. help question but it's kinda close as I'm sure some of you guys wrench on your own bikes.

So at my friends house someone(another friend) dropped off an old 80s yz 125 to hang out and be ridden. So we've been runnin this thing through the cornfields lately and we've ran into some trouble. About last week the clutch cable started to have some slack, hardly disengaged when you pulled the lever. We of course continued just riding it and kicking through the gears using little or no clutch.

Well the other day we decided to do something about it and figured it might just need some adjustment. Turned the thumbscrew adjustment on the bars out a bit and it seemed to tighten up the cable some. Here's the big problem though. Now when we start it in neutral as soon as you start to pull in the clutch lever there is a god awful grinding noise coming from what I assume is the gearbox down by the engine on the shifter side. I didn't even attempt to put it in gear or even pull the clutch in all the way as this was a really terrible grinding noise just pulling on the lever a little bit.

So NS mxers, any ideas what our problem is here?? Something shot in the clutch or maybe the gears?? I'm a noob dirtbiker and have never taken one apart but I'm sure we're gonna tackle this on our own as it's basically a POS just for fun.

any help or advice would be appreciated guys.
 
When you adjust the clutch, leave some slack in it (about 1/8"). If you've over tightened it, the clutch has been slipping this whole time.

It's probably just the clutch that's burnt out, discs and springs, simple fix, diy for $300.
 
i'm looking to get into the same type of riding. i currently ride an 06 KTM 200 EXC and that bike is a fucking blast. so light, but a good amount more bang than a 125.
 
Kalkaska looks awesome!

My friend did a national enduro up there and he said it was the most fun terrain he has ridden. I thought with it being north it would be bony rocks and stuff but it looks like new jersey!

i dont mean to whore myself out or anything but i got a sick pic from this weekend:

199200_10150128451232761_679827760_6515610_6708821_n.jpg
 
How tight did you make the cable? There should still be some slack in it. A rough rule is that you should be able to fit a nickel in between the lever and perch before it starts to actually pull the cable.
As far as it causing that grinding noise in neutral, that seems weird. You could have coincidently done something else at the time. I'd check the lever adjustment again, and if it is still bad head over the the thumpertalk.com forums and you'll find you answer easily.
 
tried to tighten it as much as possible, turned the thumbscrew all the way out and there was still play in the cable.

Hoping it's not gonna cost us 300 to fix as we could probably replace the pos for that much haha.

It is a ripper though, I've not ridden a dirtbike in easily over 10 years but I ride a streetbike. Took that yz out once through the fields and I was hooked, gotta get this thing fixed soon :)
 
There is also an adjustment on the cable, in addition to the perch thumb screw. You're cable could be fucked though. Give it a look over and see if you can find any tears, kinks or fraying. A new cable is less that $30, so it isn't a big deal.
 
I'm thinking it may have been a cause inside that made it go slack some, I mean even if the cable is shot I shouldn't be getting a gnar grinding sound out of the box when i pull the lever right??
 
Yeah I'm not sure. When was the last time you changed the oil? Something could have chipped off and be interfering with the plates in the clutch basket. It could be a bunch of things. If you are up to it you could take off the clutch cover and look around in the basket to make sure nothing is messed up in there. The easier things first would be checking the cable and possibly an oil change.
 
Whats cool about Kalkaska is it has at least 10 miles of all different terrain, from rocks and roots to deep sand, about 2 miles of whoops, and the best single track in michigan
 
I think this is what we're gonna try. I've never done this before so please ignore my noobness.

So there is oil in there with the clutch plates?? If we're removing the cover is it gonna dump all that oil?? I guess what I'm asking is even if we're just gonna inspect it for now, should I go ahead and get everything for an oil change as it's gonna leak out when we check anyway????
 
Yeah, you will need to drain the oil, so it would be a good time to change it. Here is a little video to help you through it so you don't get lost, but it is pretty simple, so you will be fine.
http://www.youtube.com/watch?v=br63PLcq3sU
As for oil, it is a never ending argument with lots of opinions. Personally I use Shell Rotella in the white bottle. It is nice and cheap and has been proven by lots of off-road and on-road users to be a great oil, without spending $12+ per quart on Amsoil or Motul. Just make sure whatever you use doesn't have any friction modifiers because they can mess with the wet clutch.
 
you are going to have to drain the oil, just look in the manual or on the internet if you arent sure which bolt it is. when you are done checking the clutch plates, basket, etc. fill it back up with oil. Also, check in the manual for how much oil you have to put back in
 
hahaha didn't fix the yz as of yet, it's not my bike so I gotta get with the owner to tear it apart and we'll split parts or something.

Buuuuuut I did go to my dad's and pick up my inherited honda cr50 4 stroke haha. thing is soooo goofy to ride but somehow fun as well. it's a little ripper for a 50, not sure what bolt on parts my bro added to it but it's got some spunk.
 
yeah they are already on it. my wacky bro painted it pink too haha, I don't care though. I'll try and get a pic up soon. My buddy was riding it a bit and he's like 6'1", it looked so ridiculous.
 
well since i got all you together, i wanna ask a question
im buying a dirt bike soon, my 1st
so... suggestions?
 
i have a ttr 230 ...a little old and a little slow, but does the job for trail riding :)

...where its really at is my summer hobby, i race street bikes :) honda cbr125rssss lots oh' funn! :)
 
I love trail riding more than track mainly because you can go anywhere, but racing track is a lot of fun too.
 
i used to ride and i had a crf150r.. i sold it awhile though and i plan on getting another bike probably after college.. this is my dream bike:

2011-Yamaha-YZ250F-Pictures.jpg
 
I have two YZ250's... Yamaha is the shit. The 250F isn't enough power for me though at this high of altitude (live at 10,500 and always ride up from here.)

Probably gonna be moving to a WR450F though cuz I want a street legal ride.

Have you seen the 2012 WR's? They are SO sexy. If I had a spare 9g's I'd be all over this:

WR450F_right_live_500.jpg
 
You must log in or register to reply here.
Back
Top