Hi all,

I just picked up a non-running trailboss 350. When i first looked at it, seemed like the carbs where just mucked up.. not the case now..

So heres what happens:

I can turn the bike over sometimes.. others i get a nice clunk.. pretty sure my electric start is seizing or on its way out as only sometimes the bike will turn over..
Now when it turns over, i can sometimes get it to backfire, or almost maybe run..

ive put a new spark plug in, nice blue spark..

Ive pulled the flywheel cover, but sadly, dont know how to check the timing. There is some oil in the bottom of the case, which leads me to believe its a seal issue.. Would this seal being blown out cause the atv to not start?

The carbs do seem to be putting fuel out to the engine, but still not running. I have tried spraying gas into the engine to get it running, but the quad just keeps turning and turning and turning.. I dont think its electrical as the guy who i bought it off said it was running 3 months ago, then all of a sudden it just didnt want to run. When i was looking at it, it would kinda start, but when you gave it gas, it would die.. now it doesnt do that at all. Is it possible that the timing is out and it causing the back to spark at the wrong time causing it to not start/backfire?

Any thoughts would be super helpful

 

Do a compression check first before you start going all over the machine. 115 psi compression or less,it probably won't crank. Plus yes if crank seals are leaking bad,it won't run either.

 

Hi there,

i dont actually have a compression tester. I did put my hand over the carb before i took it off, and it did suck, but not a heck of alot.

Im thinking the crank seal on the flywheel side is shot due to the oil, but there also isnt alot of oil, just enough to rest on the bottom of the case.. Is there anything i would have to worry about with pulling the flywheel? Also, does it make sense that the starter would seize up and cause the atv to just clunk, like it was trying to start it, but just cant?

 

You have to have a harmonic balancer puller to pull the flywheel to get to the seal behind the stator. You can rent these at any auto store. Starter armature could be dirty causing it to stick,could have gas and oil drained down in it since it's at the bottom of the engine.Have to have a clutch puller to get to the other seal This could be the noise or an internal problem,broken piston skirt,etc. May be going to the extreme on what it might be,but you need a compression test and a manual. Here's a pdf manual you can look at so you see what's all involved.http://gh-ftp.com/ORV%20Manuals/Pola...e%20Manual.pdf