Fuel pump ?

[CV16]

My dad has a 1980 Mercruiser 228. We've been having problems here and there for a few years now. I have put a new carb on it, as well as an electronic ignition. Everything was running great last season, for the most part. Every once in a while last season, the boat would not run past idle at all while under load. This year, we put it in for the first time Friday. It ran sweet for the trip out to our fishing spot, about 15 miles out. We shut down the main motor and fired up the 15hp kicker, fished for 4 hours. The main motor fired right up, but wouldn't go past idle(long ride back at 4mph!). I had put in a see through filter before the season, glad I did, I can now see that there is no gas in the filter when it runs like that! Here's the problem, this only happens once in a while. Last year it only happened early in the season and not at all the last 2 or 3 months we fished. Now my dad won't put the boat back in the water until I have this figured out. Everything checks out good as far as the fuel system check in the "Adults Only Section". Can a fuel pump work sometimes and not others? I always figured that it either worked or it didn't. The tank is clean, no air leaks and the fuel filter stays full of fuel on the muffs. I haven't ran it much past 1500 rpm, but seems good to me. Any ideas?

 

[hivoltg]

Re: Fuel pump ?

I have seen the fuel tanks anti-siphon device cause this before. Its the 90 turn brass fitting coming out of the tank. There is a check ball inside it that will stick and cause fuel delivery issues. That ball is in the wrong spot and the fuel pump puts a vacuum on it and no fuel gets thru. I would check that and clean it up or replace it. You get the boat home and that ball has moved and it works fine then.

Usually a fuel pump either works or it doesnt at all.

 

[Bondo]

Re: Fuel pump ?

Ayuh,.... Plumb in a remote tank, ahead of the fuel pump, 'n Try it,....

 

[CV16]

Re: Fuel pump ?

Thanks for the replies. That check valve was just eliminated, I put in a barbed fitting just to see if that was it. I will try a different tank, but no progress will be made until Monday. There is the Salmon-A-Rama going on, too many boats, it'd be a hasstle to get in the harbor with the kicker if we still have trouble. Today the filter stayed full of gas right up until I got out of the harbor and tried to give it gas. This was with no check valve in.

 

[CV16]

Re: Fuel pump ?

OK, now today I have bubbles in the clear test line I have hooked up. I must have an air leak that is only there some times! I'll be getting some thread dope and some new USCG approved fuel line and clamps, go through every fitting and try it again, Monday!