So, could I test for this by pouring/spraying premix into the cylinder to manually enrichen the mixture? If such a thing is possible/practical, I'd imagine I have to be careful not to pour too much in there - so as not to risk flooding or worse, right? Can anyone advise as to a safe amount to use (assuming it's not a waste of time, etc.)

wb

 

i wouldnt advise doing it that way. i would try to do a leak down test. block off both the intake and exhaust and feed pressurized air into the spark plug hole. listen for leaks

 

So, I guess maybe a similar question about "how much". Is an output pressure of, say, 20 PSI enough, or too much, etc. Thinking that the motor itself doesn't care, but that maybe I could unintentionally pop out crank seal(s) with maybe greater-than 40 PSI (?)

Since it's possible that I might be able to "just do" a full rebuild fairly quickly instead of wasting too much time trying to convince myself it's necessary, I'll ask now whether I need any special tools other than the ones to remove the clutches (both drive and driven).

If it comes down to splitting cases, will a "regular" dirt bike case separator do the trick?

 

You dont have to split the cases to replace the seals.Just remove the clutches and cover along with the flywheel and make a puller to remove the seals

 

I should have been more clear. I know the crank seals can be replaced without splitting cases. I was thinking that maybe if I decided to "do more than I had to", what tools would I need?

 

So, is a Polaris special tool required for flywheel pulling? Or can one make due with something like a harmonic balancer puller, etc?

 

You can pull it with any 3 bolt puller that will fit as long as you use the right bolts

 

Small update. Made my own leak-down test setup similar to those described at Pressure Testing - - ATV at Off-Road.com and Leakdown Tester - Banshee HQ Forums.

So far the only leak I can find is with my homemade test equipment (leaking around input valve stem). The standards I've seen published say motor should be able to hold 6 psi for 6 minutes. The leak in my test tool is slow enough to allow pressure to remain for 10-15 seconds. Spraying with soap solution seems to indicate that the crank seals, head gasket and cylinder gasket are at least as air-tight as my testing tool - they even tested fine to 10 psi.

I'm hoping my test gets better or more conlcusive once the Yamabond I've used to patch the leak in the test tool has had a chance to dry (overnight).

 

Hi wbeaver

I'm not an expert but go to my ATV Forum posting :

http://forums.atvconnection.com/pola...wont-idle.html

I tried everything to avoid replacing the crank Seals - Just do it, I am amazed at how quick my 86 TB250 starts and Idles after I changed the Crank Seals.

Timmy