1990 pro v 150 wont rev past 4000 rpm

i have a 1990 pro v 150 it wont rev past 4000 wot runs seems to run great other then that would it be the floats sticking or maybee need different prop i have a 25 pitch on it now motor is on a 18 foot bumble bee bass boat and is doing 55 mph now any ideas what i can do to make it rev higher ?i am told motor should rev 5500 rpm

Did it run at 5500 RPM for you before ??-------Have you checked for strong spark on all six cylinders ?--------Sounds like it may be running on 5 cylinders.

no it never run at 5500 rpm for me but i only used it a couple times . no i never checked spark but will

WOT (Wide Open Throttle) will only achieve maximum revs if the prop will allow it to. Will this rev higher in neutral? or when not in the water?

Have the motor tested with a marine dynamometer.-----It will determine if it is producing the proper power.-----If it is, then you will need to install a lower pitch prop. Borrow a 21" pitch and try it.

Andre Boutilier said:

i have a 1990 pro v 150 it wont rev past 4000 wot runs seems to run great other then that would it be the floats sticking or maybee need different prop i have a 25 pitch on it now motor is on a 18 foot bumble bee bass boat and is doing 55 mph now any ideas what i can do to make it rev higher ?i am told motor should rev 5500 rpm

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Andre, Way too much prop Bruh.That motor should have a 19p or 21p prop depending on what hull youre moving.Motor should turn 5700 rpms minimum to get full power out of engine,no mater how fast you are translating.

Good Boating, Moonman60

what is the best way to check for strong spark ?

If you've dropped a cylinder, check for a dropped cylinder by starting the engine with earmuffs hooked up to the lower drive providing water for cooling and with it runnign pull and replace each plug wire one by one... each one you pull should result in a drop in RPM and the engine starts to kick a bit. If you pull one and there is no change at all... that is probably the dead cylinder. If you think you found a dead cylinder... shut it down, and then stick a nail or a bolt or something metalic up into that plug wire, hold it with something non-conductive such as a wooden clothesline clip so you don't get a good jolt and then have some one fire it up. Hold the nail closer and closer to the engine block... you should see a spark jump from the nail/bolt to the block around 1/4 inch. If no spark, that's your problem. If you see a spark, could be a clogged carb or a bad plug related to that cylinder.