951-DI rave valves and throttle body coated in soot and oil

[stout890]

hello all this i my first time working on a pwc but i have plenty of mechanical experience. i have a 2000 RX-DI milinnum edition with the 951. the craft has been sitting for years (since 07) the motor has low compression according to another mechanic, thats why it was stored.

so now i have the boat and i have to engine out and on my bench. i pilled the rave valves and they both are coated in a slimy black sludge. i also noticed that the mag side intake and TB is covered in soot from the reeds up to and past the butterfly valve, while the pto side intake and TB is clean and looks good. i also noticed the air box had quite a bit of oil in it as well.

is any of this normal for this motor? i am thinking it is not. ill have to pull the mag side reed valve and inspect that. any other ideas or anyone have dealt with this before?

im going to be rebuilding this motor, so if any of you 951 DI guys want to chime in im all ears.

one other question, can i compression test a DI motor on the bench if im not hooked up to the oil tank? and the rave valves aren't hooked up to vacuum pressure

 

[stout890]

throttle body
pto side intake manifold and reed valve
mag side intake manifold and reed valve

could the exhaust soot inside the TB be from blow by past the piston rings? i don't get how it could have made it by the reed valve though because they are both in good shape

 

[stout890]

Bump.. I'm back working on this engine, I had the motor rebuilt by S.E.S still curious about the soot in the throttle bodies.