1993 force stalls at 5000 rpms

[tntony]

Hello everyone:<br /> I have a 1993 120 force that runs fine at 4600<br />to 4800 but when i get up to 5000 rpms it will run<br />for about 500 yds and the the engine rpms drop to<br />about 3500 to 4000 and stays there for about 5 sec<br />then you can throttle back to 4600 to 4800 and run all day. but as soon as you get to 5000 it<br />bougs down to 3500 or so.<br /><br /> thanks to all tntony

 

[durk187]

Re: 1993 force stalls at 5000 rpms

When you run it around 5000 rpm's does the primer bulb stay firm...I guess the question is if you pump the bulb will it stay running correctly?<br /><br />Also long has it been since you have rebuilt your carbs?

 

[tntony]

Re: 1993 force stalls at 5000 rpms

duck i dont know when the carbs was built last<br />just bought the the pontoon boat in sept when<br />i bought it it had a 17 pitch prop on it and it<br />would not turn but 4600 wot and i put a 15 pitch<br />on it now it will turn 5250 but coused a problem<br />i think the problem has always been ther but just<br />showed up when i put the new prop on. i havnt tryed to pump the bulb when it is doing this<br />i have been by my self both times it has did this<br />but i will get someone to ride with me and pump<br />the primer to check thanks what is the problem<br />if the primer being pumped fixes it ?

 

[ob]

Re: 1993 force stalls at 5000 rpms

tntony,There are a couple of things that could be amiss.If the bulb seems to be colapsing or will not stay engulfed with fuel you likely have a problem on the suction side of fuel pump.Check to insure the fuel tank is venting properly as one that is not will not allow fuel pump to draw fuel freely.Like a finger on top of a straw full of water.Also, you'll want to insure that the tank pickup tube screen is free from obstructions.Next inspect or remove the anti-syphon valve on fuel tank fitting as they are known to stick and restrict fuel flow.<br /> If primer bulb does not seem to be colapsing and pumping it seems to increase engine rpms your fuel pump could be in question.<br /> If bulb stays firm throughout operation and pumping it has no effect on engine performance you likely need to clean carbureators of deposits and replace fuel filter.<br /> These suggestions are based on the assumption that your problem is fuel related and not ignition related problem.

 

[tntony]

Re: 1993 force stalls at 5000 rpms

ob thanks for the info what could be amiss with the ign if it runs fine at 4800 that would show up at 5000

 

[ob]

Re: 1993 force stalls at 5000 rpms

That's a different can of worms.I would concentrate on process of elimination by beginning with the most common performance problem which is usually fuel related.<br /> Ignition related can range anywhere from timer base to stator windings ,etc..