johnlor

I have a 32 baja with 502 chevy big blocks. I am hearing a funny noise from one engine, always under the same conditions. I'll be out for a while running about 4500 rpms, then I come to a no wake zone by a bridge, I am in the no wake zone for about 5 minutes. When I start up again, and hit the throttles, at about 2500 rpm one engine makes a piss noise, almost like an air hose has broken. Sometimes the engine stalls out, and sometimes it drops to 1000 rpms then recovers. When I hit the gas again, it does not happen again. No matter how many times I try to stop and start again the noise does not happen. When I take the boat out again and run hard, do the no wake zone again, I get the same noise on my first launch after the no wake zone. It has also happened one time slowing down entering the no wake zone. It never happens when I'm running hard, rpms always steady. Anybody have any ideas????

TomR

Sounds like a vacuum leak to me. I would look at the carb throttle shafts to see if they were worn and replace the base gaskets under the carb.
You could try the old carb cleaner at the base of the carb when the motor is running at idle, if it speeds up that there is a vacuum leak at the base of the carb.
I doubt it is the intake itself, but check all of the bolts anyway.

Ted G

iTrader: (1)

If it is an EFI engine it might be the Idle air control sticking slightly.

GOODT

I have to agree with inspech sounds like an IAC !!!!!!