power pack problems?

[Aquanut1]

on a 1990 150hp would a powerpack limit higher rpm's and be ok in the lower rpm's ? runs ok until you go over 3000 rpm's

 

[fireman57]

Re: power pack problems?

If it is breaking down you will drop cylinders and lose power. Do a spark test when it does this to determine the suspect pack.

 

[Aquanut1]

Re: power pack problems?

the coils all were within resistanc range. I dont have a peak reading volt meter for the power pack. Is there another way to test.The motor doesn't start <br />misfiring until it's under load and running for 5 or so minutes. Are there any other components that can cause these problems? thx for the help

 

[marinemech1]

Re: power pack problems?

if engine is limited to around 3,000 rpm. it may be in s.l.o.w. (speed limiting operational warning)<br />if it is in s.l.o.w. find out why ie. overheating

 

[Aquanut1]

Re: power pack problems?

thats just what it feels and sounds like...a rev-limiter. I just had impeller and thermostats<br />put in and now have 8-10 lbs at idle and 20+ lbs at 5800 rpm's before the power drop. Is it possible the motor thinks its overheating but it's not? The alarms work thats when i knew to change therm/impel wouldn't it sound off now? thought I was imagining the truely organized misfire. Thanks

 

[Lkoschak]

Re: power pack problems?

Sounds more like a fuel restriction to me. Run the engine on a portable 6 gallon tank to eliminate the boat system from the engine. If all runs proper you have a rstriction in the boat somewhere. If you get a warning horn at WOT there is a fuel restriction. After sitting a lng time there is a lot to get gummed up. How do you know the carbs are working OK. Restricted main jets run ok at idle and mid range but misfire at max rpm.

 

[Aquanut1]

Re: power pack problems?

I wish it was fuel.. i think I have an expensive problem. I've burned about 50 gallons last week getting the prop and height rite. The boat screams until the spark is cut in half, it's like somebody snaps there fingers, then you cant get the motor over 3000 rpm and the problem started on saturday first thing. Thanks for all the help. Just read something thought it might interest someone about s.l.o.w. mode at this link http://www.maxrules.com/fixomcoisignition.html

 

[Walker]

Re: power pack problems?

Unplug the heat sensor with 2 wires, a tan and a white with blk stripe. Probably the port side sensor. That will rule out a bad sensor sending it into SLOW mode.

 

[Aquanut1]

Re: power pack problems?

if I have good water pressure is there a need for the senser. Is there a permenant mech. water temp gauge that can be fitted in the motor? <br />First day here. Great site with sharp minds.