Mercruiser problems

[chelseacay]

I have a 1997 Mercruiser 5.0 L EFI with a Bravo One with 420 hours. My problems are intermittent. Most of the time from a cold start it will start but stalls out unless I run the RPM up to about 1400 ? 1600 for about two minutes than bring the shifter back into the neutral position and it will idle at 650. But then sometimes I can just turn the key it will start and idle up by itself for a minute that fall back to 650 just like it use to do which I assume is normal.
My other problem is sometimes the engine bogs down at 3000 RPMs and will just not go any faster. I have found that if I shout the engine down for 45 minutes to an hour start it up again it will run fine up to 4400 RPMs just like it did before.
I changed the plugs, cap and rotor when it started to act this way. What do you suggest is the problem and how do I fix it?

 

[Wet Wonder]

Re: Mercruiser problems

First two things I would do - (1) check fuel/water serarator to see if it's clogged from ethanol problems, then (2) pull the plate off the distributor and check the spring weights to see if they're freezing up and keeping timing from advancing at times.

 

[danond]

Re: Mercruiser problems

I agree. Sounds like a fuel issue. I'd start with the easy stuff then work back to the tank. Fuel/water filter, kinked line, bad pump, clogged pickup in the tank.