'04 Volvo 4.3 acceleration bog fix

[Leardriver]

Hello all!

My friend's boat with a 4.3 carb 2 bbl has a slight bog or hesitation with a full throttle take-off such as a ski start.

I suspected the accelerator pump, and did the following: replaced accel pump diaphram, old one wasn't too flexible and it's a $4 part, turned up idle in gear to 600 rpm, it was at 450 in gear, tightened gap between accel pump arm and pump diaphram to the proper .015 gap at WOT, it was way bigger than spec, and replaced the .028 squirter with a .031 that I had at home. This is on the OEM 500 CFM Holley 2300 series part 75029-1 spec's by Volvo.

Before the squirt was weak and small, and now it's fat and sassy, so I can't wait to lake test it, but I suspect that the problem is solved or much better.

Have I missed any other obvious bog causes?

I re-jetted the carb a few weeks ago from a 70 main to a 68, since we are at 6,000 feet, and it runs great on the top end with good plug color and fuel economy, and that shouldn't be the cause of any low throttle position driveability issues anyway.

Thanks for the feedback!

 

[Don S]

Re: '04 Volvo 4.3 acceleration bog fix

Don't start trying to change everything, or you will not know what cures the problem.
Fix 1 thing, then check it. move to the next if necessary.

 

[Leardriver]

Re: '04 Volvo 4.3 acceleration bog fix

I agree, but when the carb was off the boat, I wanted to replace the accel pump diaphram due to its age. We'll see how it runs.

 

[Raydocraft69]

I understand this is an old post but how did the boat do with the pump replaced?