Northern Hallett

I was hoping someone could shed some light on my starting issue that has happened over the winter layup. While trying to start it will faintly fire for a few seconds. It did run for about 3-4 seconds after I cycled the fuel pump about 5 times just by turning the key on and off. Last year I put a new mechanical fuel pump on it due to a leaking diaphragm after I found gas in the impeller/fuel pump gear box while checking the oil level so that is new. I can hear the electric step up fuel pump cycle with the key, checked the lanyard switch and also checked the wires to the oil pressure switch. Last year I did put a few ounces of mercruiser 2 cycle oil in my separator to fog the engine before I winterized it and the motor sounded a little flat when I revved it up a little but I figured it was just the rich oil mixture. Maybe it was the beginning of this problem not sure. I have winterized it like this for years with no problems. So this year I changed the old separator filter out with a new mercruiser filter went down to the local ramp and it would fire but not continue to run. Could I have air in the system, I installed the new filter empty but I always have with no problems. I always have been able to service my own boats but I might be in over my head with this fuel injection merc stuff 😑 Any help would be greatly appreciated before it goes off to the dealer.

Thanks again

papps

The 525 is different because it has a mechanical and an electric fuel pump but my 7.4 mpi will not start under any conditions if I don't fill the fuel filter/separator with gas before installing. I would start there.

Northern Hallett

Thanks, for the reply. I did get up early and look it over again. I pulled the new separator filter off and there was hardly any fuel in the filter. I filled the filter to the top and reinstalled it but still it won't start just fires. It looks like it might be fuel delivery problem from the mechanical pump but it only had a few hours on it being replaced new last year with a new merc part. The cam lobe that is part of the fuel pump drive/impeller pump mechanism was inspected when I replaced the fuel pump last year and new gear oil was added. Could I have air in the system maybe. I know I should be checking fuel pressure but I really don't have any tools to do this and I'm not that familiar with it. I was hoping for an easy fix. I'll look it over some more, but appreciate your help. Thanks again

greg800le

First splash of the season and I'm having a similar problem, only the engine ran fine but when I put it in gear I got a 4 beep alarm, then port engine would stall, but fire right up, run for a minute in gear then stall again. I only idled the engine, never got out of the harbour. Trying to trouble shoot I was advised the inline fuel filter, located on the back/top port side of the engine is recommended to be changed every 30 hours on the 525. I have about 75 hrs or 2 seasons on mine. I am having the engine scanned this week for trouble codes and replacing the fuel filters, hoping to find the cause. I'll let you know what I find.

Northern Hallett

I think my problem is over. I cycled the electronic fuel pump a few more times(just turning the key switch on and off) and I heard the electric pump change tones so I'm assuming I had air in the system, still have to go for a ride but it started right up on the ear muffs and idled ok. I did see the filter on the back of the engine that your talking about and did not realize it needed changed that often. I still have to change out my impeller and housing assembly this year so I will make sure to pick up that filter as well. Thanks for the heads up on that. Let us know what you find. I've had more things break and act up during winter lay ups than actually using them. Damn winters! ��

dcb

FYI it is normal to find fuel in the cavity for the mechanical pump - I change the fuel pump oil at the same time I change my engine oil (about every 25 hours)

Northern Hallett

Doesn't it degrade the oil significantly? Extremely poor design on Mercs part. Glad it's not connected to the engine block. Thanks for the heads up. After one year mine is still all oil. I just change it yearly with low hours. Thanks for the input I appreciate it.

F-2 Speedy

iTrader: (6)

As you stated, if you don't hear the high pressure pump load down ( change pitch ) to a growl, you have no fuel to the rail

greg800le

Changed the inline fuel filters and all seems to be good. Port side filter did have some blockage. I'll be changing them each season from now on.