Leakdown.....headed in right direction?

007blaster

Member
Dec 12, 2011
340
3
49
Northern Michigan
Hey guys so I just picked up a pretty nice 01 blaster for $850 with a spare motor. The spare cases are shot they have a nice hole near the balancer where it looks like the crank busted thru or a broken skirt.
anyways I have been looking over the motor in the bike. Carb had tors removed but no idle screw lol good thing I had a spare kit. Compression is 122psi. Leakdown wouldn't even hold a psi....never got that high even! I can hear air hissing out the stator side seal. I don't have my flywheel puller so I ordered a new one with a seal kit should be here thursday. So my question is has anyone had this happen where they pump and pump and don't even get to a.single psi? Guess is the seal is completely shot. I ran the cylinder thru its stroke and looked in the exhaust and intake ports and did not see any scoring and rings look to be free not melted to the piston. from the top I don't see the lean dimple, so I think I caught it in time.
whata guys think?
Thanks !
Nick
 
I think that your leak tester just paid for itself!

I believe so too, I think its crazy why people would skip the 5 min test, guess they like blowing top ends and spending cash lol. Seals will be here Thursday, swapping clutch baskets with the spare motor, one that's in there has A LOT of rotational play.
 
I believe so too, I think its crazy why people would skip the 5 min test, guess they like blowing top ends and spending cash lol. Seals will be here Thursday, swapping clutch baskets with the spare motor, one that's in there has A LOT of rotational play.

There is a word and it is "apathy", like I fixed it, I sealed it, it is not going to leak because I know just what I am doing, unfortunatly these Mughanics eventually pay the price.

I once had a seal that destroyed itself and held absolutly no pressure, fortunatly I am experienced enough to know when the motor bogs for no apparent reason, to immediatly do a leak down test.
 
Yes an intake(reedcage to engine side) or exhaust leak (around the flange) is usually the culprit when it won't hold any pressure. But a bad crank seal would do the same thing, Just remember to recheck it after you replace those seals, Might have more than1 leak! , I don't stop testing till it holds pressure 6-7 psi for 5 minutes and 15minutes. I have found a very small leak one time by waiting 15 minutes. Damn VF2 reedcage!
 
Yes an intake(reedcage to engine side) or exhaust leak (around the flange) is usually the culprit when it won't hold any pressure. But a bad crank seal would do the same thing, Just remember to recheck it after you replace those seals, Might have more than1 leak! , I don't stop testing till it holds pressure 6-7 psi for 5 minutes and 15minutes. I have found a very small leak one time by waiting 15 minutes. Damn VF2 reedcage!

Oh yeah, definitely checking it again no reason not to .