4.3 Engine Bogs Down

[numbered01]

Hello, I am having this problem with my 1987 Mercusier 4.3 engine. Engine number B602338. It has the 4 barrel Rochester carb on it. The problem is the engine starts fine and idles good in the beginning. After I drive it for 10 minutes the engine starts to bog like it's starving for fuel or cutting out on me. I will run it at 3000 RPM and it wil drop to 2000 then back to 3000. It gets slower the more I have it running and when at idle speed it runs fine. I cleaned the flame arrestor and still has the problem. Today I am changing the water/fuel seperator and the filter in the carburator. I will see it that is the problem and get back to you. Is there anything else I need to check if that does not cure the problem?

 

[Bondo]

Re: 4.3 Engine Bogs Down

Hello, I am having this problem with my 1987 Mercusier 4.3 engine. Engine number B602338. It has the 4 barrel Rochester carb on it. The problem is the engine starts fine and idles good in the beginning. After I drive it for 10 minutes the engine starts to bog like it's starving for fuel or cutting out on me. I will run it at 3000 RPM and it wil drop to 2000 then back to 3000. It gets slower the more I have it running and when at idle speed it runs fine. I cleaned the flame arrestor and still has the problem. Today I am changing the water/fuel seperator and the filter in the carburator. I will see it that is the problem and get back to you. Is there anything else I need to check if that does not cure the problem?

Ayuh,... Don't Just change the fuel filter, Inspect it's contents,...

I'm guessin' you'll find water, 'n crud...

 

[Oshkosh1]

Re: 4.3 Engine Bogs Down

Don't assume it's fuel related...Not saying it's not, but nonetheless, often times fuel/ignition problems can exhibit the same symptoms.

If it's been awhile since the last complete tune-up...I'd start with that.