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1989 90 giving me fits, Won't go to speed, Will go to speed.

N

nkemens

New member
1989 Evinrude V4 90 HP. Ran like a top for the last 3 years until 3 weeks ago. I am stumped. I have ordered the factory manual, but it has not arrived yet. I need some troubleshooting things to check in the mean time. The kids are getting mad, no more tubing.

I bought this in 2009 from the original owner. I converted from VRO to the old style fuel pump and run 50:1 with Quicksilver oil mix all the time. The VRO pump had a crack in it. It has always had a slightly rough idle. I figured this was normal for a 90 HP. Above idle, goes very well (especially on a 700# 16’ Starcraft).

It has run flawlessly until 3 weeks ago. We were tubing and it seemed like it was running out of gas after 30 minutes or so (it seemed early to switch tanks but I quickly switched them and pumped the bulb a few times and no change. The motor seemed to be starving. I moved the control to full throttle and the max it would go was 2300 RPM. That was it. I tried squeezing the bulb a few times again and no improvement. We slowly motored the 3 miles to the dock at 10 MPH. Normally 5300 RPM and 40 MPH. We trailered it home and it sat for a week.

The kids wanted to fish, after a look under the cover, for the obvious, I checked the fuel strainer on the pump and it looked clean. Reassembled, Idled in the driveway for a short time on the hose and it seemed back to normal and we took it to the lake. It screamed OK, for about 300 yards, 5300 RPM. Full speed perfectly then started to drop off again and back to 2300 RPM. It seemed to not be running on all 4. At an idle, it seemed to run real rough, stalling often. We shut it down, fished for 10-15 minutes, started again, it ran well again, perfect and full 5300 for 100’ or so and then the same, 2300 RPM, seemed to skip and we motored it in again.

The next night after work I went ahead and cleaned the fuel pump strainer again (even though this does not seem like a fuel related issue) and took the pump apart, it all looked like new. I also checked fuel pump pressure (4-5 PSI). I checked compression Left Bank 110,110, Right Bank 125, 120. I checked each plug for spark with a timing light as well, all good. When I removed the upper left plug wire from the coil to see if it idled any worse, I noticed a spark from the plug coil connection to coil input wire. I had a spare coil and replaced it. Put it all back together, let it idle for a while in the yard and it seemed to run better.

We took it to the lake. It screamed great for about 15-20 minutes, 5300 RPM full speed perfectly, we were high-fiving but then it started to drop off again momentarily, back to 2300 RPM a few short times @ full throttle, then back to 5300 and ran well again. I squeezed the bulb when this happened, no change. We shut it down, I removed the engine cover, used the timing light on each wire, it seemed each was firing evenly. I left the cover off, it ran pretty well, but only reached 4400 RPM. Never 5300 again. 4400 was it and the idle seemed rough. The power pack seemed hot to the touch right after removing the cover. It seemed cooler with the cover removed. Anyway, 4400 back to the dock. I am not an outboard motor guy, but it seemed the timing is somewhat retarded.

After deciding it was not fuel, and having and Amazon gift card, I ordered a Power Pack. I replaced it and took it out again last night. Same thing, 4400 RPM is it. No 5300 at all. It seems to run OK at speed, but it could be running on 3 cylinders the best I can tell. I only removed the lower left wire from the plug after pulling the cover, and it seemed to make no difference at speed with the plug wire on or off. Lacking a plug wrench, I took it home.

I removed the bottom left plug, it was wet with gas/oil. The others were all dry. I replaced all the plugs with my last set that I cleaned and kept in the Glovebox. While in the driveway, on the hose, I pulled each wire and each made the idle real rough and each had a spark jumping over an inch. So I knew they are all firing (at idle at least). We took it to the lake again and no difference, 4400 RPM is it and a pretty rough idle.

Anyway, I need a checklist of things to check until my shop manual arrives. I am stumped! One final thing, my battery is not the best. I have 13.4V running at speed and 12.4-12.8 at idle. When off only 11.8 or so. Could it be a float in one of the carbs sticking? Rectifier? Stator? I just do not know until I get a manual.

Your help is very much appreciated.​
 
One of those V-4 motors will idle smoothly ( all day long ) if in good condition !!------These motors have a history to them ----The first item to do is a compression test !!-------Next thing to do is check for good spark , which means it must jump a gap of 7/16" on all 4 cylinders.----Report the results of this testing.-----Not sure why folks throw new powerpacks on motors without some simple testing.
 
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Sorry, I typed a lot of text:
I checked compression Left Bank 110,110, Right Bank 125, 120......
While in the driveway, on the hose, I pulled each wire and each made the idle real rough and each had a spark jumping over an inch to the plug.
 
Checked flywheel key ?-------------Next time out on the water shine a strong flashlight into carburetor bores at full throttle and compare amount of fuel coming up the main jets.-------Confirm that high speed jets ( 4 of them ) are clean.--These are screwed into the float bowl from the side ( lower one is high speed ) and are removed with a 3/16" diameter screw driver.--Have you inspected the reed valves ??
 
you may have two problems....look at timing advance....there is a little roller inside a slot that advances the timing...this is a steel roller with a fiber glass looking cover on it that increases the diameter...this fiber glass? cracks and pieces eventually falls off down into the bottom of the lower motor cover.... you will not get proper timing advance with it broken...it time for a battery..bite the bullet and get one...the rectifier has nothing to do with the running of the motor...it charges the battery and feeds the tach...this entry in no way is meant to interfere with Rivers recommendations....thats the route to go...
 
I have a 1990 120 VRO, I'm sure they have very close specs as far as torque on the flywheel nut, it needs to be 150 foot lbs (1800 inch lbs) thats from the Evinrude manual, I ended up with sheared flywheel keys because I didnt tighten mine enough. It took 2 of us to torque that nut, one holding a bar to keep the flywheel from turning and one to torque the nut. Make sure it's TIGHT!!! I'm going to add a photo of the bar I made up to hold the flywheel as there wasnt any other way to hold it securely to torque otherwise, I'll put it in my Flywheel removal thread.

Your engine symptoms sound like mine, I had several issues, mainly a faulty intermittant powerpack (good spark one day bad the next), partially bad voltage regulator (tach inop), probably degraded original spark plug wires (I could see sparks running it at night), questionable old spark plugs and I sheared several flywheel keys due to my ignorance of the torque value. These guys are great help, but get that manual and work through testing the components and report your findings.
 
thanks to you all. I looked at the reeds through the carbs. they are shiny and clean. The'flywheel has not moved and is good tight and keyed. I remember that little plastic bushing when I first got it. It was laying i the bottom of the motor and I replaced it with a vinyl one that is still fully in tact.

The mosquitos were thick tonight and I got home too late to start it. too much noise. tomorrow night I'll be on it again for sure. I also got some seafoam for the fuel.

I ordered new plug wires just because they are old. I also put on the old Powerpack to keep the new one sellable.

carb kits are on order too along with a new set of NGKs. The factory 1989 manual is shipping tomorrow so I'll have it next week along with the rest of the parts.
 
tach does work fine. I've got my trickle charge on the battery.It's just weak from sitting and the boat is only used once evey three weeks. Actually right now it's 12.6v from all of my recent troubleshooting trips to the lake. The motor charges well.
 
I would say the flywheel has not moved only if you can see both the key slot in the flywheel and the crankshaft, on mine you could see the slot for the flywheel but not the crank and even then, you had to remove the flywheel nut to do so. I removed the nut the first time and did not get it tight enough when I put it back on, therefore inducing my own problem. While I had the flywheel off the second time I ground a notch in the top of the crank that aligns with the flywheel so I know where the crank slot is so I dont have to completely remove the flywheel to check again.
 
Hi, I got tthe same problem with my 120. It idles good but you never know if it will run at wot.I thought i had it several times,pimer bulb, coil, spark plugs, ignition wires,carbs, vro ,ugh it still does it.Well im going down to check the spark and check a carb that ran low from a pinched fuel line.Maybe check the tank vent also..
The vent will be number one And t to think i let my trouble free searay sit all summer.:(
 
I rebuilt the carbs this weekend. Easy to do and they were spotless. No gunk in them, not a particle of dirt/sludge, all jets completely shiny, gaskets clean. There was a thin 3/4"x 3/16" to 1/8" ribbon of RTV/orange gasket material near the bottom of the lower carb bowl right inbetween the high speed jets! Looks like it may have come from the fuel pump as it is on the only thing with a gasket that color. I hope that may have been the problem. As the jets are under a vacuum under speed I could see this getting sucked into them. I blew all the ports out with compressed air. No need to use any carb cleaner as everything was as new. I use Stable Blue, it must work. I havn't got the carbs fully installed yet as I had to fight the rain and the very tight installation quarters in the motor (wow, not much room to connect hoses back in place). I hope to have it back together over the next two evenings with a set of plugs and wires too.

My fingers are crossed. I will check the timing after all assembled. All of the linkages appear like new, no slop and all bushings in tact. I also was able to see and touch all the reeds with the carbs off. They are clean, with no carbon or gunk on them whatsoever.

Thank you again! ...Norm
 
Hi Norm,

I was reading your story and the same exact thing happened to me this past Sunday! I have a 1987 90HP Johnson, the only difference was that I had to travel 8 miles at 8 MPH! I had my sending unit replaced the week before, and the engine worked great until this past Sunday. Upset, I went to see my mechanic today and explained what happened. He said it's not a fuel problem, carb issue or anything to do with the timing or flywheel...he said it was definitely the powerpack. He said sometimes in this case if it works, then doesn't work, it's an intermittent power pack. My temperature gauge was on the borderline of green/red because the engine was working so hard. Since the temp sensor is on the portside of the engine (which gives you the reading on the temp gauge), my mechanic told me that the powerpack on the starboard side was the one that needed replacing. I'm going to buy it this week and change it out. I'll keep you posted.
 
My 90 only has one power pak. the 6 and 8 cyl have two. I bought a new one, replaced it and it made no real difference. I put the old one on and started troubleshooting again. It seems to run the same with the old one in place. Tomorrow I will finish the carb install, new plugs and wires and check the timing. I may get to the lake Thursday or Friday to really know. Again, give it a try, but thepower pack was not my problem. Hopefully the issue is one of the items I did work on. From what I hear the PPs either work or they don't. but I have heard so many stories. I will troubleshoot the stator and other things under the flywheel if these other things do not do the trick. I have a PP with 30 minutes on it for $73.00 + shipping!
....Norm
 
nkemens said:
My 90 only has one power pak. the 6 and 8 cyl have two. I bought a new one, replaced it and it made no real difference. I put the old one on and started troubleshooting again. It seems to run the same with the old one in place. Tomorrow I will finish the carb install, new plugs and wires and check the timing. I may get to the lake Thursday or Friday to really know. Again, give it a try, but thepower pack was not my problem. Hopefully the issue is one of the items I did work on. From what I hear the PPs either work or they don't. but I have heard so many stories. I will troubleshoot the stator and other things under the flywheel if these other things do not do the trick. I have a PP with 30 minutes on it for $73.00 + shipping!
....Norm
Click to expand...
Hi,
*I bought a omc manual for my year motor it cost about 90. These motor's are just to complicated for the novice.My advice is to find a shop that has a good mechanic who has worked on these motors and ask them to troubleshoot it for you.My motor is at the shop now ,im waiting on a answer .The troubleshoot shouldnt be more than a hour labor and youl save alot replacing uneeded parts. Ill let you know when the verdict comes in on my 1988 120.Till then the searay goes in.
 
hi, I got the call from the shop and they isolated the problem to the power pac.Checked evrything out and that is what they found.Ordered the new part and will install next week.In case it doesnt work they said they would put the old pac in at no charge.The mechanic has many years in this work and said he repaced only a few timer bases and this one doesn't act like one.he also found a error in my vro install and corrected it.There was no fuel issues he could find.
The power pac was replaced in 2006.Many OMC parts are now made overseas so there isnt much difference in sierra and omc now.


[/QUOTE]View attachment 5290
 
these motors are not that complicated at all....there are two basic things that need to be checked before starting to troubleshoot....the compression shoud be within 10% on all pistons...the spark should jump a 7/16 inch gap...after that the decision should be is the problem a fire or fuel problem?an inductive timing light is about 40 bucks and is tool i use for that...you can spend a fortune throwing parts at a problem and some repair shops will do the same..trouble shooting is the way to go.....and make sure you are working on the problem and not out in left field throwing parts in or rebuilding carbs when the problem is electronic ...or vice versa......
 
Hi guys,
I finally replaced my powerpack as I stated above, and it seemed to run fine. However, I did not have the boat out as long as I would like, so I wonder how much stress I was placing on the engine to see if it would shut down again. The one thing I did notice is that my temperature gauge is right at the edge of green/red, and the motor did get a little louder once the guage climbed towards the red zone- which obviously is expected. Could it be that both powerpacks needed to be replaced? The water is pumping fine out of the motor (which is cold water), so I'm wondering what would make this gauge climb so high. Any thoughts?
 
Hi guys,

I spoke with my mechanic yesterday, and he recommended replacing the water pump and both thermostats. I just bought this boat last Fall, so I really don't know the maintenance history behind it. He thinks there might not be enough water pumping through the engine at high speeds, which is why he believes the temp gauge is rising to the verge of overheating. Any thoughts?
 
All is done. Rebuilt carbs, new plugs, wires, a seafoam flush and last night a hi-temp warning while on the ears. Tapped the tstat housing and it started to cool and the alarm turned off. Must be a sticking stat on top of the issue. I have ordered a kit. Anyway, taking it to the lake tonight to see if my fixes worked. Seems to run ok on the ears. My manual arrived too.

...Norm
 
Well, great news. She goes perfect and better than ever. Hit 42 with 3 in the boat, started without priming and it purrs like a kitten. No leaks to boot. Thank you for all of you help! I could not have done it without you! It had to be the rtv in the carb.
 
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