BBC tuning question?

[whitey70ss]

A friend of mine has a bbc in a jet boat the engine idles fine but as soon as you bring it of idle it starts popping through the exhaust. I tried moving the distributer to the left and it got worse so I tried to the right = worse. I'm wondering if its in the carb its a marine style holley p/n R84018-2 Any suggestions would be helpfull. Thanks

[fatjodycat]

im thinking rounded lobe on cam.

[TS1955]

Broken or weak valve spring(s).

TS1955

[russ67chevelle]

running lean???

[Tod74]

A friend of mine has a bbc in a jet boat the engine idles fine but as soon as you bring it of idle it starts popping through the exhaust. I tried moving the distributer to the left and it got worse so I tried to the right = worse. I'm wondering if its in the carb its a marine style holley p/n R84018-2 Any suggestions would be helpfull. Thanks

why not put a light on it...time it correctly and stop moving it? That would eliminate that variable. Not being a smart alek just a suggestion.

[cepx111]

I'd pull the valve covers and do a looky loo.

He's probably got a broken valve spring, broken rocker arm or pushrod not on the rocker arm, been there done that, I hate that sound.

[oldandtired]

im thinking rounded lobe on cam.
x2
I've seen it too many times on BBC marine engines. Dave

[whitey70ss]

took the valve covers off found a broken spring . I appreciate the help. sorry I'm such a amature :oops:

[BEAST477]

Don't be sorry. Everybody has to start somewhere. The easiest way to learn is ask ???