Hesitation at mid-range RPM

[Glastron175]

I have a 2000 Volvo Penta 3.0L with a 2 barrel Holley. I put in a rebuild kit and it seems to have solved the idling problem, but it still will bog down when at about 3000 RPM and I advance the throttle. If I juggle the throttle a little I can get it to go on up to higher RPM and it runs fine at the higher RPMs. I wondered if it could be that the accelerator pump is not giving it enough gas . When I check the accdelerator pump with engine off, it does squirt gas. Can it be the adjustment for the accelerator pump? Any other ideas?
Thanks.

 

[Bondo]

Re: Hesitation at mid-range RPM

I wondered if it could be that the accelerator pump is not giving it enough gas

Ayuh,... It could be, or more likely, there's still crud in the carb....
You cleared the low-speed circuit, 'n possibly moved the crud into the hi-speed circuit..

 

[SeanMcl]

Re: Hesitation at mid-range RPM

I don't need answers to these questions, but they are a good place for you to start troubleshooting.

Which rebuild kit did you use? Genuine Holley or Sierra? Sierra has a bad reputation. Did you tear it down to the metering block and blow out all the holes? Is the power valve the correct one for a marine/high load application? Did the new gaskets match up with the old gaskets and did you make sure that none of the passages were blocked by gasket material? Did you check the accelerator pump clearance under the pump cam? If that is off you will have fully used up the fuel in the pump by mid throttle and have none left for that upper range. Did you pull the accelerator pump nozzle off and clean it out? It is located under the throttle plate and comes off with a phillips head screw (at least on my Holley 2bbl).

 

[pvmtsux]

Re: Hesitation at mid-range RPM

Since you just rebuilt the carb I'd start there. Tear it down again and go back through cleaning it. If that doesn't fix the problem then I'd move on to the accelerator pump.

 

[Glastron175]

Re: Hesitation at mid-range RPM

Thanks for the suggestions. I hope to get it out again this weekend. First I'll try adjusting the lever on the acc pump. If that doesn't work, then I think the next step is to order a Holley kit. Yes, I used a Sierra kit.