I'm guessing my valves are leaking but now I don't know [Help!]

[The Buddha]

Ha ha, funny you should mention I need a new mechanic.  I am my mechanic!

Again, I was mistaken calling the test a leak down test.  I just put a little oil in the cylinder and remeasured the compression.

I've done this stuff with guidance found here.  I'm going to redo the sync at idle and I'll be looking at the carbs soon too.

Thank you for your help

K you put oil in the chamber and got 200 psi ... ok you dump another oz or 2 of oil in there and get hydrolock. End of problem. Then you just need a connection rod set.

What is surprising ... you take away 10 cc from a chamber that is only ~27cc to start with and you're surprised you have 200 psi ...

Dude you got water in the gas, or oil in the air filter or such other stupid crap. Or gas in oil or gas in water or water in oil or gas in air ... take your pick ... your bike is fine. Oil, gas, valves adjusted and ride ... any problem beyond that is $$$ to diagnose and $$$ to fix.

Cool.
Buddha.

[burning1]

Hehehe... Wow, after 4 years, I never thought about how adding a little oil to the cylinder would affect compression, simply by displacing air. To be fair, I usually use 2-3cc of oil, not 10.

[The Buddha]

My guess ... not for sure he added that much.
Cool.
Buddha.

[4strings]

I put in as much as a cap for a gallon of milk will hold

[burning1]

Sure, but it really makes sense. I think I calculated the volume of the GS500 at TDC as being under 30cc. Just 3cc should theoretically increase compression reading by ~10%.

[4strings]

Wow, didn't know that.  Cool cool, I gotta clean up in the garage so I have some space to pull the carbs apart.  Then we'll see what happens.

Thanks guys

[The Buddha]

That oil in chamber is a better test for a leakdown ... in a compression test it can shoot the number artificially high ... however that in effect is telling you its retaining the oil, hence it is sealing up just fine.
So ignore the high number and say that your rings are good.

Flashlight in the sparkplug hole and looking in the exhaust/intake port is a ghetto way of checking if valves are closing. Lopee did that and found out a bent exhaust if I recall. I gotta start on that head he dropped off and check it out.
He now has a super cool rd400 he's been ridign round after selling the GS.

Cool.
Buddha.

[The Buddha]

Or shine the light in the exhaust/intake port and look in the sparkplug hole ... I dunno. Somewhere you shine and somewhere else you look. Make sure its @ compression stroke though. Not intake or exhaust.
Cool.
Buddha.