MCM 120 Fuel Pump Going Bad?

[BillysBoat1986]

Hi everyone! Was out cruising in my boat with the 1987 2.5L. It was running perfect for about a 45 min run at WOT. We anchored for about an hour and started heading back. We ran for about 15 minutes again at WOT then suddenly the RPMs dropped to about 3500. I didn't touch the throttle. It stayed there for about 5 min then suddenly I heard a pop through the flame arrestor. It wasn't loud like a backfire but noticeable. After that it went back to normal RPMs and we made it back to the marina without further incident. Do you think I had a momentary lag in fuel pressure? This is the last component on this engine that hasn't been replaced or rebuilt. Thanks for thoughts and/or advice.

 

[alldodge]

Don't know what happened but may have got some crud in the carb, may have a fuel pressure issue. The only way to check the pressure is with a gauge. They don't cost much and would be worth a look

 

[Bondo]

Ayuh,..... Check the fuel filter in the fuel pump, 'n the 1 in the carb's inlet fittin' for crud,....

 

[BillysBoat1986]

Checked the inlet filter on the carb and it was clean. Went ahead and ordered a new pump. I really don't trust the one installed now. It's gotta be as old as the engine. Found one on the Summit Racing website for under $100 also.

 

[alldodge]

Hope your getting a marine pump and not an automotive one. Was just at Summit and I didn't see one for a 2.5L MCM 120

There is two types for the 120, old and new style. New style cost less then old style

86234A05 Old
8M0073435 new

 

[BillysBoat1986]

Yes it's a marine Carter pump. Here is the link. https://m.summitracing.com/parts/CRT-M60032 I have bought lots of parts from Summit for cars... first for a boat though. I'll update on how it is when I get it and install.