'88 Evinrude 150 won't exceed 1500rpm's in drive

[Forester 150]

I have a '88 Forester w/ Evinrude 150hp that dies if you try to go over 1500rpm's in drive while on a lake. It tests out fine with muffs and runs good in neutral and reverse on the lake. The alarm did sound a couple of times, so the VRO was checked out to make sure it is operating and the lines/ filters are clean and primed. I also replaced the plugs and checked water flow.

 

[Joe Reeves]

Re: '88 Evinrude 150 won't exceed 1500rpm's in drive

Check compression... What are the individual cylinder readings?

With s/plugs out... check spark... should jump a 7/16" gap with a strong blue snap! Does it?

If the above areas are okay, clean and rebuild the carburetors. Manually clean the ID of the four high speed jets, 2 to a float chamber.

 

[emdsapmgr]

Re: '88 Evinrude 150 won't exceed 1500rpm's in drive

That engine will seem to run just fine on 3 or 4 cyls when idling on the trailer. You need all 6 firing when it's in the water.

 

[metriccrescentwrench]

Re: '88 Evinrude 150 won't exceed 1500rpm's in drive

..... runs good in neutral and reverse on the lake. .....

Is there a shift interrupt switch on that engine? (I assume from what was posted that the engine can make power well about 1500 rpm in reverse.)

 

[Forester 150]

Re: '88 Evinrude 150 won't exceed 1500rpm's in drive

Is there a shift interrupt switch on that engine? (I assume from what was posted that the engine can make power well about 1500 rpm in reverse.)

I will check for that since it runs fine in reverse and well above 1500rpm. It is only running poorly in forward gear. And a couple of times on Friday it had lept onto plane only to cut off so a circuit is definitely telling it to shut down. When it is in the power down (maybe SLOW) mode, it does seem to run on only three cylinders. I will run a bunch more tests when I have some more time.

 

[emdsapmgr]

Re: '88 Evinrude 150 won't exceed 1500rpm's in drive

I believe the SLOW feature first came out in 89 with the advent of the single power pack. Keep in mind that weak ignition components tend to fail once the engine heats up to normal operating temps. Do your spark checks when cold as well as when it's fully warmed up. That engine has a number of alarms-what sound did your alarm make? An overheat is a constant solid tone. Is the timer base advancing when throttled up in forward gear?