1989 evinrude wont go over 2000 rpm WOT

[Mickeyburch88]

I'm fairly new to boating and bought a used boat with a 1989 evinrude 90hp motor on it. When I bought it it fired right up on muffs with no problems and I didn't think to take it out on the water. First time out it was hard to start in the water , finally got it running and went to open it up and wouldn't go above 2000 rpm. So I took it to a local mechanic who suggested the carbs needed cleaning so got that done and same problem . Then he said could possibly be a powerpack and checked that and it was bad... replaced that and he also threw in the anti-siphon valve just incase. Still wont go above 2000 rpm. He said it compression tested fine but while running it the other day seeing if I could find anything there were some bubbles coming out of the side of the intake at the gasket . Also the number 1 cylinder is getting spark but the spark plug is covered in oil after its run and its the only one that does that. any suggestions on any other probable causes?

 

[ncfyreman]

I WOULD SUGGEST LOOKING INTO CHANGEING THE GASKETS. LOOK AT IT LIKE A CAR ENGINE IF YOUR CAR PLUGS ARE IN OIL YOU MAY HAVE A BAD HEAD GASKET SO IT WOULDNT HURT TO CHANGE THEM ESPECIALLY SINCE YOUR SEEING BUBBLES

 

[flyingscott]

Do a compression and spark test before anything. Unless your mechanic told you a # for the compression test re-do it. A leaking head gasket on a 2strk motor does not let oil into the cylinder you will either have a compression drop or water intrusion

 

[Mickeyburch88]

Alright guess I'll start by doing that on my own he never said the numbers just said it checked out .

 

[oldboat1]

saying you found a leak at the intake manifold gasket?

 

[Mickeyburch88]

yes there was a leak . Had some bubbles behind the number one cylinder at the intake manifold gasket. also compression test was good on all the cylinders.. over 100 on each .. I did notice the last time that while it was running the primer bulb wasn't hard? I don't know if that could be a problem . I don't have a gauge to test the fuel pressure.

 

[oldboat1]

Got to fix the intake manifold leak, as that affects the air/fuel mix. (Won't affect a compression test.) Replace the gasket.

 

[Mickeyburch88]

Thanks ! I didn't know if that would make that much of a difference or not on a boat . Have to get on that this weekend and see how it goes after

 

[oldboat1]

Intake leaks typically give lean running, sometimes dangerously lean. You seem to have a rich condition, at least in one cylinder, so not sure how to put that together. Good opportunity to make sure the leaf valves are flat and intact while you are in there -- might as well check.

(Here's a piece from a two-cycle site that I find instructive: http://www.klemmvintage.com/airleaks.htm )

Post back -- let us know how it comes out.

 

[Mickeyburch88]

So I got it all back together and it was still running funky. Hooked up a timing light and it's way out of time beyond the point of adjusting it back by the adjustment lever ..? The number one cylinder is close to 90 degrees off I'd say . Hard to tell since the marks only go to 36 but it's quite a bit passed that

 

[jbuote]

Not an expert by any means, but have you checked flywheel key?

​I believe if you take out spark plugs, and rotate engine so #1 cyl is at top of it's stroke, then timing mark should line up to 0 or TDC..
​If not, then flywheel key might be sheared, and flywheel slipped so it would throw timing off..

​Again, no expert, but that's the thought I had after reading this..

​For what it's worth.. lol

 

[Tim Frank]

So I got it all back together and it was still running funky. Hooked up a timing light and it's way out of time beyond the point of adjusting it back by the adjustment lever ..? The number one cylinder is close to 90 degrees off I'd say . Hard to tell since the marks only go to 36 but it's quite a bit passed that

I have been running outboards for 50+ years and have never had to play with the timing on any of them.
My experience is that about 90% of the problems encountered are almost trivial when found, and cheap and easy to repair. The trick is to find them by systematic and focused troubleshooting.
If your timing were "close to 90 degrees off" it would not "run funky"....it just would not run, period.

It was suggested by one of the more knowledgeable members that you check compression and spark. You have reported back with your compression #s, but nothing about spark. As a suggestion, re-read post #3.

Once you have done the spark test, you can move on to the fuel system. (don't do the "ground the plug on the block anmd it looked good test", use an open-air gap tester set at 7/16".

Proper testing will avoid simply replacing parts willy-nilly and hoping that you get lucky. That is expensive sport.

(once you have verified the spark, no reason not to check for a sheared key. if the key were sheared, replacing the key "retimes" the motor. No need to play with the adjustments.)

 

[flyingscott]

So I got it all back together and it was still running funky. Hooked up a timing light and it's way out of time beyond the point of adjusting it back by the adjustment lever ..? The number one cylinder is close to 90 degrees off I'd say . Hard to tell since the marks only go to 36 but it's quite a bit passed that

Highly doubt it would run like like that. My guess is you either do not have the timing light on the right plug or you pick up is feeding off of the cylinder below it. If the #1 piston does not have spark and you drop the pick-up so it touches #2 wire it will be 90 deg out.

 

[Mickeyburch88]

Well I switched the powerpack back to the original hooked the timing light to it and it ran perfect.. the part number on the side of it was different than the one that he had replaced but just by one number. I don't know For sure that's what it was but it's in time now and I'm guessing it was the gasket leaking was the other part.

 

[Mickeyburch88]

And the compression on all 4 cylinders was just above 90 and it held the compression pretty well . The spark originally was checked by the mechanic that said he had tested the powerpack and that it was bad but when put back on it ran fine. I did pick up a spark tester today though just incase so next time I have all the right tools to diagnose it myself instead of having to listen to someone who I'm guessing was just trying to make some easy money

 

[flyingscott]

Get a different compression tester 90 is not good.

 

[Mickeyburch88]

Well crap I just got this one

 

[Mickeyburch88]

I would like to say thank you to everyone who commented though even though it seems like nothing wants to stay the same on it . You've been awesome and after 3 weeks of tweaking stuff myself and few weeks at a mechanic in a week on here at least part of it was figured out.

 

[jafitzwater]

I have had this motor previously, and had the same issue... the motor would run fantastic on the muffs with the cowling off, then on the water would bog down at 2k rpm. Turns out that the cowling had one of the clips was getting very close to the spark plug wire and every time I throttled up it would arch the bolt on the cover and fall on its face never going over 1800-2k rpm. I opened the cowling, tightened down the bolts, then sprayed them with rubber coating... problem solved.

 

[Mickeyburch88]

I'll have to try that too it does get stuck in the clips if you don't put it on just right. Even had it rip a plug wire off befor