1991 yz250 torque

Hi everyone! Im very new to this forum as ive just gotten a bike recently. I've been looking on here for quite some time so here it goes. I have this 1991 yz250 and I can barely get it up in third gear. Do you think this could be because I dont have enough power/ compression or something? I'm not exactly sure if I should be getting it up in fourth but from what I hear I should be. So any help would be greatly appreciated!!! Thanks in advance!

What do you mean when you say "I can barely get it up in third"?  Does that statement mean that it won't lift the front end in third?  It won't rev out in third?  Are you trying to go up a hill lugging it in third?

 

What type of riding are you doing?  Any idea when the topend was gone through last?

If you don't know the last time the bike had a top end then it needs one.   Else clean your air filter.

Ya i mean i can barely get the front end up in third and I mostly trail ride but i'm starting to ride tracks.I have no clue when the top end was done because I just got the bike and I asked the guy I bought it from and he said he didn't know either but he didn't ride it often. I kinda had the feeling it was the top end. I will try the air filter as well and see if that helps. Thank you for the replies! 

Edited by yz250ripper

How about the compression, but just to be save pull the piston or better have a look through the exhaust port and see if the piston is gone.

I was just thinking about doing a test and ok. Do you guys think its possible it could be crank seals too? It doesnt bog at all or die on me, ive never fouled a plug and it idles fine but idk. I just think that because a guy at my local shop told me and said its possible cuz its an older bike............. I think he was just tryna make money but again idk.

Edited by yz250ripper

Could be any number of things, even a slipping clutch.

I'd start with a compression test, some plug chops and get jetting dialed.

Try doing a wide open pull in 3rd, and stand on the rear brake in the middle of it to see if the engine rpm gets pulled down. If it doesn't and you are slowing with the brake then the clutch is slipping.

Reeds and crank seals are a possibility, but both should give idle issues.

Powervalve function is another.

Sounds good to me! I will try all of that. I doubt its the powervalve or jetting because the guy I bought it from said he recently did a carb rebuild.

Sounds good to me! I will try all of that. I doubt its the powervalve or jetting because the guy I bought it from said he recently did a carb rebuild.

Yea, and the guy I just bought a bike feom said it had a fresh top end. Entire engine is thrashed and full of sand. Everything is junk.

Good point. I will go through it. I was just thinking he was telling the truth because it doesn't really sputter or anything and the carb looks cleaner than all the parts around it. 

Yea, and the guy I just bought a bike feom said it had a fresh top end. Entire engine is thrashed and full of sand. Everything is junk.

I'm going through the exact same thing. Rebuilding top and bottom end during weekends when I have time. Found sand in the reeds and it only gets worse as I dig in further....

Sounds like people really suck and @ Thinlineggman Nice bike! you powdercoat the frame?

Good point. I will go through it. I was just thinking he was telling the truth because it doesn't really sputter or anything and the carb looks cleaner than all the parts around it.

He may have just cleaned the carb. But that doesnt mean its jetted correctly, or that the powervalve is opening.

Ya true. Im just gonna go thru everything like u said but I honestly just think its the top end after reading up a whole bunch because I think the bike runs good its just a lack of power. I think i'm just over worried that something else is wrong when its not. I'm gonna take it out today and play with the carb and see what happens...........

Edited by yz250ripper

 

Im just gonna go thru everything like u said but I honestly just think its the top end after reading up a whole bunch because I think the bike runs good its just a lack of power. I think i'm just over worried that something else is wrong when its not. I'm gonna take it out today and play with the carb and see what happens...........

post the bike running and riding through the gears on utube and you will get better feedback.

Thats a good idea. It may even be just some carb adjustments because i took it out today and it bogged a little bit on the lower end rarely but it did happen. So i'm gonna check the pilot jet and see how that looks. I'm just going to do what adam said and go thru the carb. It keeps seeming like more and more of a good idea.................. Adam I think you were right :worthy:

Sounds like people really suck and @ Thinlineggman Nice bike! you powdercoat the frame?

Thanks!

A previous owner did the powder coat. I love the look of the bike, but I sure wish I could just ride it!!!! That's the bike I'm having to do an entire engine rebuild on, unfortunately.

every 250 I have ridden would pull wheelies in all gears With a tug on the bars, all the way from my '89 CR250 to an 2003 CR250, 3rd gear should be childsplay for a 250 2 stroke.

 

does Your bike have Stock gearing? or is it set up for high speed\wide open riding? if not then I would suspect something in Your engine is in bad shape.

 

does it rev out as it should? if it revs up fast but just feels like it lacks Power, it could be a slipping clutch.

So the carb ended up being dirty and cleaned itself with a little bit of WOT riding from sitting at the guys house i got it from. It easily pulls in 3rd, barely have to pull forth and a nice tug in 5th. but i still think it could b slipping the clutch cuz im having some issues shifting cuz before i changed the oil after just changing it like 2 rides ago and it kept hitting neutral wen i was hillclimbing. I also had problems shifting into first from neutral with the bike off and the clutch pulled in at a dead stop. I just changed the oil again and took it for a little putt around the block and its not doing it anymore so idk..... 

Edited by yz250ripper

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