Engine experts please help me out......

[1996Z15]

I have been having problems lately with my 1986 Minx. I can't get passed 3800 RPM's now. At first I was having problems where the engine sounded like it was running on seven cylinders then it would clear up. This past weekend I noticed that the alternator belt was so loose that, when it was flopping around, it had started to cut into the water hose. I noticed this black nasty stuff on the falem arrestor, I'm guessing that it was the rubber from the hose that had been sucked in around the flame arrestor. Anyway, I changed both belts, replaced the water hose, cleaned out the flame arrestor, cleaned out the carburetor and changed the plugs. I thought for sure I would've fixed any problems with these changes. I take it out for a ride to check my handywork and the friggin' boat acts up again. About 5 minutes into the ride it starts the seven cylinder thing but when I jump on it the carb spits once and it ran fine since then but it still won't go past 3800 RPM's. In fact, if I put the throttle all the way down the boat falls flat on it's face but if I back out of the throttle slightly the boat speeds up.
When I was changing the plugs I noticed that the fuel pump is looking kind of old, could that be the cause of my problems? I'm not a mechanic, by any means, so I have been playing the old "hit and miss" game with my attempts at repairs.
Could someone give me some ideas so I'm not chasing my tail anymore?

[smoothie]

Give us some info to work with,what motor,carb,and ignition are you running? electric fuel pump?did you do a compression and vacuum check...I like a good mystery :D

[1996Z15]

The engine is the factory Mercruiser 350 Magnum with, what appears to be, a Rochester carb. The stock ignition, in fact, I think the whole set-up is factory stock. I did not do a compression check since I don't have the tools or the know how to do this myself.
I forgot to mention that today, with a little less than 1/2 tank of fuel the "low fuel" light would come on when I was coming off of plane.
Any help would be appreciated.

[Cuda]

Fuel filter, water separator?

[1996Z15]

Water seperating fuel filter - just replaced

[BUIZILLA]

My guess is you have TWO problems. I have 2 of these EXACT engines in both my LE boats, so I know them pretty well by now.
1) Change the cap and rotor
2) When you removed the flame arrestor, somehow the pull off linkage for the secondary's got stuck, which would explain the new bog scenario. With the arrestor on, check the linkage link on the starboard outside side of the carb from the choke pulloff to the secondary air valve arm. It will be in plain view. If you care to, remove the arrestor and take a spin and see what happens, but run the bilge blower ALL the time you do this. OR, when you put the arrestor back on, somehow the holdown bolt got jammed in the secondary metering rod hole, instead of the correct threaded hole, and the air valve/metering rod linkage is now jammed.
3) There is a short vacuum hose from the front base of the carb to the choke pulloff module, make SURE it is on tight.
4) Rochester carbs have a small filter inside the inlet stud at the carb base. Carefully, using a flare nut wrench, remove the line, then the inlet fitting, throw away the filter and spring, and reinstall your inlet flange and line.
5) See if your fuel pump has a small filter under it. Some did, some didn't. Remove, inspect,clean and re-install if it does.

J

[smoothie]

Man you Minx guys stick together :cool: Yep it sounds like a fuel problem to me also,I would start at the gas tank air vent and work your way back to going into the intake,I agree with B sounds like your secondarys arent kickin in.

[1996Z15]

Thanks for the replies; I'm gonna have to wait until next weekend to check into it since I have other things going on. One last question and it might seem stupid but when I change the rotor and cap can I use a high performance cap from an automotive application or is a mrine cap / rotor different in some way?

[MOP]

Another thought, pull the top off the carb blow out all the tiny passages and clean the bowl. Many times I have found junk in the little bleed orifices always blow back in the direction it entered or you may just drive it in deeper and rarely is the bowl really clean even with good filters stuff finds its way in.