Volvo 5.0GL-A Carb slight bog down

[gapple12]

So, I took my boat out for one last spin yesterday before I winterize for the year, and since I bought it Ive noticed a slight bog at mid to low throttle. When slowly advancing the throttle, around 2000 RPM the motor will slightly hesitate. If I keep adding power it goes away and jumps past it. Its not real bad and if I advance throttle faster I don't notice it, but I'm curious where to start looking for this issue. I think I will start with changing the carb inline fuel filter and running some carb cleaning threw the carb. I also will replace the cap and rotor to see if that helps. Any other ideas on what to check or replace ?

 

[Maclin]

Re: Volvo 5.0GL-A Carb slight bog down

It could be that the accelerator pump shot needs some work. The accelerator pump is inside the carb and is actuated by throttle movement. Sometimes that linkage can be out of adjustment depending on the brand and style of carb.

With engine off, and flame arrestor off so you can see down the carb throat, see what kind of stream comes out of the accel pump nozzles when you move the throttle very slowly. Then, move the throttle to just past idle, about where it would be when crusing at 2000rpm, then move it slowly and watch the nozzles again. If at any time it is not a stream but more like drops then a stream then the carb may need some work.

Double check your ignition tuning, make sure cap. rotor, wires, plugs, timing are all in spec.

At 2000rpm it should be past where any contribution is made from the idle circuits, but you might look into that (idle circuit air bleed adjustments) if the above items seem ok.

 

[gapple12]

Re: Volvo 5.0GL-A Carb slight bog down

Man, I'm still fighting this issue. Went boating this past weekend and this issue is still happening. Trying to pull a skier it will hit a bog down spot and can be frustrating when pulling a skier out of the hole. Ive changed the cap and rotor, checked all connections to the carb and still have the issue. As Maclin stated about the pump shot, would this be resolved with a carb rebuild kit ? My boat only has 85 hours on it and since the boat was rarely used, could there possibly be a build up in the carb or spark plugs ? Boat is a 2002.

 

[MikDee]

Re: Volvo 5.0GL-A Carb slight bog down

Did you do what maclin said? If so, what were the results? It's easy enough to test. Do you need a carb rebuild? We don't know, if you don't try what's requested. It would help direct us as to which direction to look. Sometimes low hours on a vehicle, boat, car, motorcycle, can cause a different set of issues.

Have you put a timing light on it to see if it's right?

 

[Walt T]

Re: Volvo 5.0GL-A Carb slight bog down

Is this a Holley? If so what Maclin said. If it's a Qjet then it's probably secondary restrictor flap.