1989 PRO V 150 POWER PROBLEMS

[provoutah]

I have 1989 PRO V 150 that started dropping rpms as I was going down the lake it dropped all the way down to 1100 rpm's. It runs fine for the first five minutes then it starts. At idle it seems to run fine. The engine will rev up fine with the warm up. No alarms and the oil is full. Just looking for a place to start.


Mike

[jb123]

check pump ball when problem occurs, SOUNDS like your ball may be collapsing, not allowing fuel delivery.could be the tank vent clogged, causing vapor lock in tank, then the ball would collapse.
you will be looking for something preventing higher end fuel flow.
i have had the same motor for 13 yrs and the ONLY issue ever is dirty carbs.

[provoutah]

I checked the ball while the problem was occurring, it was fine. I also checkd the fuel pumps, changed spark plugs,drained carb bowls, drained fuel tanks and put in new gas,checked temp and oils sensors, all checked OK.I pulled the new spark plugs and 3 of the cylinders did not appear to be firing. Could the motor be in a low power mode. I had it cut out like this one time when the oil got low. Refilling the oil did the trick but this time the oil is full. However the oil was low when this started. I am pulling what little hair I have out please help before I am bald

[jb123]

how did you check the fuel pumps? if theyre over a few yrs old, i would just replace as general maintenance.
first i would use a aux tank to isolate the prob.
when at a higher idle, say 1200,pull each plug wire and listen for a non change in rpm/SOUND to try to isolate a non firing cylinder.
then remove airbox and same rpms, use your finger to simulate choking of each carb opening and listen again for a non change of sound/rpms.
or use a spray bottle of gas and spray in each opening.
when it comes to the electrical side of the nonfiring SIDE you describe, i have light experience there as LUCKILY, i never had electrical issues with any of the 9 yammies i have owned.

i DID however have to shrink wrap ALL of my coil power leads as they were arcing out, causing poor performance....you will only see this at night.

[Demise08]

Solution?

Hey I'm having the same problem you had. Did you find the solution? And if so what was it?