YZ250F Lemon

My brother has a 05 yz250f used and it seems to cause so many problems and we have only had it for like 1 month. First we found out the valves went bad, so we got them reshimmed by a mechanic. Ran fine for about 2hrs and now the bike has almost no compression and seems like there is no reason to even try starting it. What the hell is it this time

your auto decom working???

User error?

flooded?

Try draining the carb pulling the plug, recheck all the wire connections.

Smooth kicks not super hard and see if you get a pop. Or try and bump start it.

If you get it to sputter it is carb if no sputter then electrical.

troubleshoot...

used huh? never raced? owned by a 35 fun rider? Welcome to the world of used race bikes. People run them into the dirt for the season and rather than rebuild them they sell them to victims.

Plan on a set of intake valves and a cam chain at a minimum, but it wouldnt surprise me at all to find extensive wear in the motor.

All bikes need reshimed regularly. People just dont usually do it. One thing worth trying would be to check to see if the rings are offset, I blew my bike pretty bad back in February. $2,500 later and it didnt run. Pulled top end off and rings wernt offset. We offset them and bam started right up.

All bikes need reshimed regularly. People just dont usually do it. One thing worth trying would be to check to see if the rings are offset, I blew my bike pretty bad back in February. $2,500 later and it didnt run. Pulled top end off and rings wernt offset. We offset them and bam started right up.

Yeah, I'm gonna have to say &%$#@! to that one. Do you ride a Honda? Yamahas don't need reshimming regularly. Mine has never been shimmed with over three years of hard riding. And of course, if you don't index the rings properly when doing a top end you will have problems. If the bike in question has never had the top end apart then that wont be likely. The problem is most likely in the valves, you need to start by checking the clearances.

I have had a mod and stock 250f all year, never reshimmed the stock, runs fine. My mod got messed up once and it was because of the valve clearance.

Mine has never needed reshimmed either and we run hotcams and race them. However I will say that the guys that do end up needing to shim their bikes need to do it more than once and finally have to replace them typically.

i had to reshim right off the bat.

and now I am on the low side so i will re-shim to get the specs in the middle of the scale.

Don't see what the big deal is? it cost next to nothing and takes an hour max to do...

i had to reshim right off the bat.

and now I am on the low side so i will re-shim to get the specs in the middle of the scale.

Don't see what the big deal is? it cost next to nothing and takes an hour max to do...

It's not real uncommon to have to re-shim after a new bike breaks in. It is, however, uncommon to have to re-shim on a regular basis.....unless you own a crf.

My brother has a 05 yz250f used

FIrst off a used bike is a used bike. If you did not inspect it properly when purchasing, this is going to be a tough learning lesson for you.

and it seems to cause so many problems and we have only had it for like 1 month. First we found out the valves went bad,

First off how does a valve go "bad"? Second if there was a problem with the valve, replace the damn thing. You dont shim a "Bad" valve - ie I am assuming you mean a bent or broken valve if it is bad.

So what other "so many problems" does the bike have? Sounds like one.

so we got them reshimmed by a mechanic. Ran fine for about 2hrs and now the bike has almost no compression and seems like there is no reason to even try starting it. What the hell is it this time

Well do the basics. Check spark, compression and fuel. You will find your troubles out.

And the work you got done on the bike, who did it? A wanna be neighbor or actually a reputable shop?

All bikes do not need reshimming regularly! I rode my '03 YZ250F over 100 hours and it was perfectly w/in spec when I sold it.

Sounds like this bike was flogged to death, unfortunately.

i think last time the valves either completly closed or opened...dont remeber. i wasnt there to check the bike even though they said i would go when buying it(not my fault). ill try checking some stuff but this is so annoying.

i think last time the valves either completly closed or opened...dont remeber. i wasnt there to check the bike even though they said i would go when buying it(not my fault). ill try checking some stuff but this is so annoying.

,huh?

,huh?

what he said what does all that mean????

I rode a wr426 (01) for 7 months, riding the trails in australia solid. Shipped it back to the uk, then rode it hard for another 3 years. After that I thought I ought to check the valve clearances and replaced one shim that was actually not quite out of tolerance. I've never come across a harder wearing off-roader than the WR's.

Got an 05 WR250F, no regrets.

last time the bike caused problems it was either the valves opening or closing...never really looked into it myself.

when the bike was purchased i was supposed to go look at it with my dad and brother(since i know the most about what to look for), but for some reason they went without me. i wasnt there to look at the bike before it was purchased. i think that if i was there we wouldnt have it right now because the frame was obviously repainted and the engine covers were replaced with new stock ones. i do believe the guy rode the crap out of the bike. the weird thing is i heard now that the guy is a mechanic for Pro Circuit(although im not positive) so i would have expected it to be taken care of better.

:banghead::banghead::lol::busted:

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