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dmarucci · April 5th, 2020, 01:28 PM

Danno,
So, After all my new gaskets arrived, I did a wet compression test:
2 ml of Valvoline 20W50 full synthetic motorcycle oil in each cylinder via a syringe and a rubber hose (right at the edge of the piston)
Rotate with 14mm socket by hand through a few rotations.
Compression test each cylinder open throttle.
Both went up to 125 psi - exactly.
This bike only has 20,400 miles and I know the owner for its entire previous life. He says he was very good about oil changes. There's no way the bores / ring / pistons are THAT worn. I'm thinking the rings are stuck from sitting.

Thoughts?

I'm going to try the piston ring soak method you outlined here:
https://www.ninjette.org/forums/showthread.php?t=343925

It's not looking too much like a head gasket or valves anymore. I guess only a leak-down test would tell.

April 5th, 2020, 01:28 PM	#4
dmarucci ninjette.org newbie Name: Daniel Location: La Puente, CA Join Date: Mar 2020 Motorcycle(s): 2007 Ninja 250r, 2009 BMW R1200RT, 1968 Yamaha YCS-1 Posts: 4	Interesting development Danno, So, After all my new gaskets arrived, I did a wet compression test: 2 ml of Valvoline 20W50 full synthetic motorcycle oil in each cylinder via a syringe and a rubber hose (right at the edge of the piston) Rotate with 14mm socket by hand through a few rotations. Compression test each cylinder open throttle. Both went up to 125 psi - exactly. This bike only has 20,400 miles and I know the owner for its entire previous life. He says he was very good about oil changes. There's no way the bores / ring / pistons are THAT worn. I'm thinking the rings are stuck from sitting. Thoughts? I'm going to try the piston ring soak method you outlined here: https://www.ninjette.org/forums/showthread.php?t=343925 It's not looking too much like a head gasket or valves anymore. I guess only a leak-down test would tell.