Srlawrence05

After I am running the 440 when warm, when I got to turn it off a few seconds later it puffs kinda loud out of the carb and out the valve cover breathers? Can't figure out why.

Archer

Lawrence -

Ah, too much timing?
Try backing it off a bit and see what happens.
If that doesn't help, you have to start thinking valves.

Archer

Coronet 500

Welcome.

Is your crankcase ventilation system in place and working properly?

Check your PCV and hose for vacuum at different rpm's.

Gorts 5th

I agree with archer where s your timing set.
Im thinking it needs to be around 6* btdc.
Archer is that correct? On a b.b.

Archer

Hey Gorts, good to see you again.

Depends on the year and other stuff done to it, but a lot of mild 440s like about 10* initial and 32* total. But YMMV.

Archer

Gorts 5th

Thsnk you same to you archer its refreshing to be back.

Srlawrence05

yea I have evac hoses hooked up to each exhaust. It's on jet boat. But I will check and see if they are working properly

Srlawrence05

i have timing set at 36* at 3000 rpm

Srlawrence05

also has a fresh valve job done so I wouldn't think that's the problem

Archer

Lawrence -

No idea about about 440s on jet boats, since drive train resistance is a little different than on a car/truck.

Without a pretty decent sized cam and possibly higher than std octane fuel, 36* total may be a little too much. A new valve job unfortunately doesn't preclude a bad or sticky valve.

Bumping the advance back a few degrees is a quick and easily reversible test, so I would start there.

Archer

RacerHog

At this point.... I'm going with Condensation & Vapor Mist....

Iowan

I'm thinking broken ring or piston.

RacerHog

Could Be....

Gorts 5th

My budy had a leaking head gasket and he would find the dip stick pop off it's seat. With light oil spray about the compartment.
And i agree the timing curve is very diffent in a jet boat than a automobile.
I wonder ....the grinds are they diffent...for marine engine's?