Why Leak Down Testing is a MUSTTTT DO

[AcidRayn]

i've been rebuilding a 100.00 basket case,
http://www.blasterforum.com/full-rebuilds-128/100-00-98-blasket-case-rebuild-31836/
and finally got the engine together,
put together a leak down tester, (i had one years ago, don't know what happened to it), and did the test today., mind you, i ALMOST said the hell with it and just put the eng in the frame. well, i could not get it to hold pressure, after some checking with some dish soap, i found the intake leaking at the gasket, and the crank shaft seal on the stator side was defective.

here is the defective seal that came with my vitos crank. thanks vito, you almost got to sell me a new piston. the seal was definitly defective and not damaged, you can see it when its up close that the inner part is molded wrong.

heres the tester i put together for under 10.00 (i had the gauge from a low pressure tire gauge)
the shrader valve is nothing more then a rubber tire valve that i shaved down to fit in the hose, then clamped it in

again, this test is a must do, this cheap azz china crap that vito sent me could have cost me a ton of time tearing it down again, plus a wasted piston, rings and gaskets as well as a re hone!!!

TEST ITTTTTTTTTTTTTTTT!!

 

[brandoz28]

my cheapo ones that came with my wiseco kit weren't much better



they seals straight from yamaha, even though they're a few bucks more, they're way better. so.......

extra 15 bucks on seals? or 200 on a top end rebuild.....that's a difficult decision lol.



rep for spreading the word on the leakdown bro!

 

[AcidRayn]

my cheapo ones that came with my wiseco kit weren't much better



they seals straight from yamaha, even though they're a few bucks more, they're way better. so.......

extra 15 bucks on seals? or 200 on a top end rebuild.....that's a difficult decision lol.



rep for spreading the word on the leakdown bro!

hey, props up for the rep man, mucho appreciated.

yea, this was really aggravting. i found it at 4:30 and the closest dealer is 40 min one way, lucky they are pretty cool and know i been in there for alot of stuff for this build, so they took my card over the phone and left the seal, (2, gota a spare) in a bag behind the dumpster for me cuz no way i was making it there before they left.

 

[brandoz28]

that's awesome. the dealership here in town gets tired of seeing me i think lol

 

[89yamaha]

I just changed out my reeds... should I do a leak down test? I have never done one before.Where can I get a leak down tester and do I need a compressor do charge it up?

 

[OConnor Racing]

Nice catch boss!!!

 

[super noober]

how long is it before vitos prices start to drop because noone is buying thier junk anymore?? it seems like it just keeps getting worse.. 89yamaha, holeshot man sells the leakdown testers here for 30 bucks, or just look at the one acid made and copy it. a bike pump works best for them because you only want around 7-10lbs of pressure.

 

[89yamaha]

how long is it before vitos prices start to drop because noone is buying thier junk anymore?? it seems like it just keeps getting worse.. 89yamaha, holeshot man sells the leakdown testers here for 30 bucks, or just look at the one acid made and copy it. a bike pump works best for them because you only want around 7-10lbs of pressure.

Thanks I'll get one just to make sure

 

[blasterdemon7]

I just changed out my reeds... should I do a leak down test? I have never done one before.Where can I get a leak down tester and do I need a compressor do charge it up?

Yes. Reeds are a commen leak point. You call buy one on here for about $30. All you need is a small bike pump.

 

[AcidRayn]

DO NOT ATTEMPT TO USE A COMPRESSOR FOR THIS TEST!!!!!!!!!

I can't stress that enough. There is a chance you can blow the

Seals right out of the case. Use a bicycle pump, 5-7 lbs. 5

Is all you need, if it holds 7 you got rock solid seals.

Yea , so done with vito's. I think all the cranks are made in china

Now. O what I would do for anjapanese made product these days.

As far as gen. Yamaha, I had a set of yAmaha seals, don't know

What I was thinking. I guess I never expected defective seals.

I used the gen yamaha ones I. The spare engine I'm Putin together