R Addiction

Did you check the fuel pressure? I had a fuel pump crap out on my 502 MAG. The boat would run ok until I went over 4000 RPM, then it would nose over and the fuel pressure gauge (on the dash) dropped off. Got out of the throttle and pressure came back up and would run fine. I checked for bulletins on Mercruiser site and found one for a fuel pump. Bingo.....new pump.....no problems!!!

L9X25

Masher,

You need to get a handle on this problem before a minor problem costs you serious money. If the fuel pump is your problem (leaning out on top) you can melt that engine down very quickly. Make sure you have a fuel pressure gauge installed before your next WOT run. If the pressure drops get out of it immediately.

articfriends

You'd most likely have a real black,wet plug,or but les likely,you could have a plug with electrode burned away,w/aluminum speckles on the porcelein. The biggest thing you should look for would be a plug that looks different from the rest,Smitty

masher44

I have ran it 3 times trying to get the problem solved. I have been at WOT but it has been for brief periods, 15-20 seconds. Is my best bet to just go get it hooked up to the computer? I think I have ran it enough to know it is not plugs, filter, etc? The plugs were all pretty much the same. A couple looked a little different, one was a hair darker than the rest and a thin coating of black soot was on all of them and one had a very slight bit more. But the boat ran great up to 4400. Does anyone think I cooked a cylinder. I have not done a pressure test or checked the fuel pressure at WOT yet. Thanks Guys!!!!!

masher44

PS. and my gauges, Temps, Pressures look fine during operation.

bobl

Sounds like a fuel pressure issue to me. Check to see if this engine has a fuel filter in addition to the seperator filter. Some do but not all. Run it with a fuel pressure gauge. If you're near Austin I can help you solve it if you don't have any luck.

Bob

masher44

Hi Bob, I am in Granbury and I am not too comfortable with not knowing any mechanics ( new to area) Fountain of Dallas is a 2 hour ride through the dreaded metro plex and Austin might be a good option. Are you in the business. If you are, I am also looking to trade up to a 35 Lightning. Thanks Jim

masher44

PS. It is a 2003 29 Fountain w/ a 525 EFI.

robyw1

One day I hope MerCruiser and for that matter many automotive manufactures will make fuel pressure a monitored part of the EFI system. Right now it is a guessing game and many technicians will not look past idle fuel pressure in an EFI troubleshooting routein. Most times this problem is accidently repaired as a result of expensive parts changing.

Roby

bobl

Jim, I'm in Spicewood. It's 2 1/2 hr drive from Granbury at the most. I've got a good friend that lives in Granbury. I've got a small shop and am Mercruiser certified. I do high performance work as well as routine maintenance. I am a Nordic dealer but can't help you on the Fountain. I'll make you a great deal on ordering a 35 Nordic though.