wont start, cleaned carb , only 100psi when cranked , people said I need crankcase seals . Does anyone know exactly which seal it is because there is 2 gaskets on this web site I am lookin at and what tool I would need to do this sorry first time . If anyone can help please

 

did you do a leak down test to see if the seals are bad? did it run lean when it was running? 100 psi is right on the border of having a new top end done but still should start. does it have fire when you try to start it?

 

check pipe for raw gas build up

 

Also to add to what he said did you check to see if the crank case was full of gas?
If it seals you need there are located around each end of the crank.
search my name I have described replacing crank seals a few times you should be able to find everything you need to know.

 

My friend have one same thing before has trail boss 250 1986. Do you might need rebuild bottom end if need. When you gone bad seal need both rebuild bottom end new bearing and seal. Did you last time rebuild top end done?

 

Not necessarily, there could be many reasons as to why the crank seals have failed. most commonly they are old and have stood the test of time, secondly something could have made its way to the seals, P.T.O. side a blown belt not cleaned out of the case will take out a seal. Mag side, could be old rusted shrapnel bouncing around inside the flywheel. Who knows.
There could be 100`s of different reasons as to why the crank seals have failed.
If I were you and wanted to keep the quad running I`d do a top end rebuild as stated before 100psi is on the bottom end of premium run-ability (is that a word LOL ). First of all replace the seals they are cheep and easy to do, once you have the motor all sealed up it should run but with 100psi don`t expect to pull catwalks out of the hole.

 

Your correct. I know about this. But thank you.