# Need help with 90hp evinrude



## Fordracing2105 (May 1, 2015)

I have a 1983 90hp evinrude that losses spark on two cyl under load. I have tried changing plugs new power packs new coils still the same problem. Every now and than it will fire on all cyl for a second or two than quit for awhile. Would this be the stator ? Can I change the stator wires to the opposite side to see if it moves the side that's not firing? Engine does seam to idle ok but has a hiccup here and there. Thanks in advance for any help.


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## Pappy (May 2, 2015)

Since the timer base moves when you accelerate, see if there are any wires on it that are rubbed by the flywheel when it moves or possibly a kink and subsequent loss of continuity when you move the timer base. You can check each wire for shorts to ground with an ohmeter while moving it. You can check for open leads between the common and each of the leads that go to the side you are losing spark on the same way. Engine does not need to be running to check these. 
The Charge coils on the Stator can be changed side to side to see if the issue follows the coil.


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## Fordracing2105 (May 2, 2015)

Ok thanks Pappy I'm going to give this a try tomorrow. It stinks that I have to go to ramp to try this but I only live about 10 minutes away so I guess it's not to bad.


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## Boat2fast (May 10, 2015)

I got a 1984 90hp Evinrude a while back. The VRO oil supply line hardened up and cracked. It let the oil pump suck air instead of oil...burnt up the powerhead. Too bad, but I stripped everything off the powerhead before junking the carcass. It ran perfect before the oil problem. Everything is sitting packed in a plastic storage container. Would that be something interesting to you?


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## Fordracing2105 (May 10, 2015)

Boat2fast said:


> I got a 1984 90hp Evinrude a while back. The VRO oil supply line hardened up and cracked. It let the oil pump suck air instead of oil...burnt up the powerhead. Too bad, but I stripped everything off the powerhead before junking the carcass. It ran perfect before the oil problem. Everything is sitting packed in a plastic storage container. Would that be something interesting to you?


Dang I just ordered a new timer trigger the other day. Everthing else is either new or swapped off of another motor. The trigger was the only thing I couldn't get a hold of.


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## Fordracing2105 (May 12, 2015)

Well I got my new timer. Does anyone have a link on how to set timing?


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## Pappy (May 12, 2015)

Obviously you need a timing light and a piston stop to do it correctly. Assuming you have no piston stop then keep the timing around a degree or so below what it is supposed to be set at.
Two ways to do it since I would imagine you dont have a test wheel. 
One is to run it at WOT across the lake and either you or a buddy check the timing. 
Second way is to (at a ramp) submerge the gearcase far enough to cover the water intakes while leaving the tips of the prop blades above water. 
Your boat will still be on the trailer and tied down. The engine should be able to reach around 5000rpm or so. Someone needs to run the throttle and hold the steering steady and straight. 
Run the engine in gear to WOT and check timing. One turn on the timing adjustment screw is around 1 degree of timing. Adjust and re-run to verify. 
The engine will shoot one Hell of a wall of water this way but its faster and safer than you hanging over the engine at WOT going across a lake.
You may hear that you can disconnect the timing from the carb pick up and do it at a low or no throttle setting. The timing will advance beyond where you set it if you do it this way so it is not recommended.


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## Fordracing2105 (May 12, 2015)

Well I just got in from working on it. I do have it idling now. I saw that I could pull all plugs run throttle at wot and crank with starter. Than I could set to 4* below what it should be set at. This was enough to get it running but is not right. Now I can head to the ramp. I do have a timing light no piston stop or wheel. Haha now I get to buy more tools. I'm going to the ramp to try and set timing tomorrow. Thanks


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## Fordracing2105 (May 12, 2015)

What is wot timing anyway I read that it is 28* is this right?


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## Pappy (May 12, 2015)

Usually printed on a sticker on the air silencer cover.


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## Fordracing2105 (May 13, 2015)

Mine doesn't have that sticker. Just idle adjustment and starting.


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## Fordracing2105 (May 14, 2015)

Well went to the ramp last night and it's firing on all 4. I don't have a tach signal and batts not charging now. 
The other night when I changed out stator it did the same thing dropped two cyl. Last night it did the same thing till I swapped coils my new coils where shorted out no spark. I assume that the stator took out my new coils on that side and the rectifier. So I guess once I had new stator on I still had two bad coils which gave me the same no spark. 

I still have a miss don't know which cyl it is and can't see it in the timing light. Motor sat for 4 years so might just need ran and cleaned out a little I'm sure there is a lot of carbon build up from all the idling and not firing it did. 

Oh and I did the ramp trick to set timing I have it at 28* right now till a get a manual.


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## Pappy (May 14, 2015)

The ramp trick is kind of fun to do isn't it!


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## Fordracing2105 (May 14, 2015)

Yes it is.


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## Fordracing2105 (May 22, 2015)

Well went down to the river last night for a test. Was a no go again. This was a good running motor that I had on a pontoon a couple years ago than it sat in garage for two or three years. Anyway down at the river as soon as I would open up the throttle a hair you could tell there was some power there but losses it right away. Boat would rev up to 2000 rpm at 15 mph and no more. Ran like that for about a minute. Than I started playing around with it and figured out that if I push and hold the key in it would jump up to around 3000rpm and about 23 mph as long as I would hold key in it would stay up at that speed but would pulse would rev up to 3000 down to 2000 ever 5 seconds or so. Carbs where clean twice this year than a full rebuild. Didn't see any adjusting screws on them. Not sure if I have a fuel problem now or still a spark or timing issue. I do have a manual now for some reason it lists motors before and after mine on timing and there 28* but says to go by sticker on mine that I don't have. Today I'm going back down to ramp with help and going to try and set everything on timing and carbs to manual check spark with timing light to see if I'm losing any under load still and check plugs and well that's about it I'm lost at that point and input you guys can think of.


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## Pappy (May 22, 2015)

WOT timing will not be the issue. 
You mentioned holding in the key switch. Good information. 
Did you physically pull all the high speed jets out of the bowls and clean them? As a matter of fact did you pull all the jets out and clean them and the passageways behind them? The brass lift tubes? Did you clean and verify each one of them? If not, you will be going back in there. 
An easy way to tell what is going on at this point is to get yourself a squirt bottle of gas/oil. Take the front of the air silencer cover off. At the RPM where the problem is occurring take the bottle and squirt some mixture down each throat. You will find the cylinder that needs fuel. The engine will pick up immediately when you hit the right cylinder. 
Remove that carb or all carbs again and do your job over. 
If you cannot pull the HS jets easily take a butane torch and heat the bowl around the area the jet is at and remove it then. I think you will find your problem there.


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## Fordracing2105 (May 22, 2015)

Pappy said:


> WOT timing will not be the issue.
> You mentioned holding in the key switch. Good information.
> Did you physically pull all the high speed jets out of the bowls and clean them? As a matter of fact did you pull all the jets out and clean them and the passageways behind them? The brass lift tubes? Did you clean and verify each one of them? If not, you will be going back in there.
> An easy way to tell what is going on at this point is to get yourself a squirt bottle of gas/oil. Take the front of the air silencer cover off. At the RPM where the problem is occurring take the bottle and squirt some mixture down each throat. You will find the cylinder that needs fuel. The engine will pick up immediately when you hit the right cylinder.
> ...


I pulled the carbs and like you said I didn't pull the hs jets. I did blow and stick a wire in them. I remember that but there is plenty of room for gunk to build up behind them. Clean them again and took to the river. Boat ran great for a little while than the motor slowed and about locked up. I tried to start it but starter would barely turn over the motor. Waited alittle it now turns over a little faster but won't start. I came home and checked compression and is 95 112 112 115. I'm pretty sure the last time I checked the cylinder was up around 112 or 115. Pulled plugs there nice and tan or light brown looking doesn't seam to be lean. I guess I'm going to check starter spark and battery now.


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## Fordracing2105 (May 22, 2015)

Just checked compression again the 95 cylinder is back up might of been something I did earlier. I'm pretty sure it's getting fuel plugs are getting wet with fuel. Motor backfires out exhaust. Have spark on all cylinders.


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## Fordracing2105 (May 22, 2015)

Oh and motor shook like crazy right before it stopped. I checked linkages and flywheel key.


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## Fordracing2105 (May 22, 2015)

Well just pull flywheel off completely because it acted like a timing problem and sure enough it is a sheared key. Last time I just pulled but and look it see if it was lined up it was but broke.


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## Pappy (May 23, 2015)

You are having your share of issues! 
There are only three usual ways to shear a key. Running in a resonance RPM range which I am guessing you are not. Not cleaning the tapers prior to placing the flywheel back on the crank (most likely culprit), or not torquing the flywheel. If either of the last two was the reason then a piston stick/rapid decel can create a key shear. Not normal or likely but it can. Lets hope it was just a key. 
Now, unless you engine was far enough out of time to kick back against the starter the lock-up may be a concern. 
Compression drop you found may have been the key to it. 
On a light piston stick the engine cannot be turned over by the starter immediately after the stick. After a couple to a few minutes the piston cools enough to free itself from the cylinder wall and the starter can do its job better. After idling and slow running that area that stuck kind of "heals" itself to a degree and compression numbers can come back up a little. 
Unless you feel like pulling that cylinder head and looking in there or pulling the intake by-pass cover and looking in there then just be aware that it may have stuck and you will need to run extra oil for a while and run easy to flush debris that will be coming off the walls and piston. 
If it stuck a ring with debris it will shorten the service life of that piston/cylinder. Not trying to scare you...just educate you.
Now, let me get this straight, you still have not physically pulled the HS jets? Without pulling them and cleaning them there is absolutely no way you can tell me or fool yourself into absolutely knowing they are clean. I would rather see your engine running with a completely closed off HS jet than one that is still just dirty enough to create a lean condition. And that run may have stuck the piston. Hello? 
The plug color will not change fast enough on a single WOT run to let you know the condition. 
Do your part the right way and quit taking short cuts. If not then my help is done.


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## Fordracing2105 (May 23, 2015)

Yes I did pull the hs jets I said in an earlier post that I did that. I'm sorry I didn't word it right. Not sure what short cuts I took. And yes it was my fault that the key sheared I never tighten nut nut the last time I had the flywheel off from doing the timer. Sounds like you already had enough. And the boat ran great right before key sheared and I thank you for your help.


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## Pappy (May 23, 2015)

Not that I have had enough by any means. 
Through the years I have offered a lot of help to a lot of folks on this stuff. Most of the time it was done according to plan. Sometimes short cuts were made and problems persisted. Other times different folks would say to do something else . At these points I have learned just to step back and let things happen. Or, as in the case on these forums, sometimes bad advice can cost a person money and I will offer information with back up and try to get it back on track.
As long as you want to get it right and do things the right way I still enjoy trying to teach and help.


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## Fordracing2105 (May 24, 2015)

Your help is greatly appreciated from me and others. And I understand not everyone listens to what or how there told to go about something. So what short cuts did I take from your advice. I had practical everything off of this engine at least 5 times things have been check double check Replaced swapped out test and I forgot to torque the flywheel because I figured it would have to come off again. All I was doing each time was hitting with an impact quick. I wouldn't really call that taking any short cuts.


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## Pappy (May 24, 2015)

Short cuts.
I guess since others are reading this and hopefully learning from it this would be a good chance to go over what a "carb cleaning" is. 
As I said earlier....much rather see an engine run on a totally blocked off jet than one that is only partially blocked. Your short cut was
before the help started so no short cuts while the help was available to you. Your short cut was to not remove the jets but to just stick something through them and cross your fingers. With mistakes comes knowledge and experience!
When a carb is disassembled (OMC for reference) all jets should be removed and chemically cleaned. Also a good chance to take a number drill and check the jet size. 
Orifices and passageways behind jets should also be cleaned and verified by either air, pressurized chemical (tough on the eyes...) or a strand of wire. If not sure....re-clean. Calibration pocket plugs (those aluminum plugs) that reside on the tops of carbs should always be removed and each calibration hole should be verified. Try not to stick anything into them. Brass lift tubes that go down into the fuel column in the bowl and supply fuel to the idle circuit should be cleaned and verified by one of the above methods. Anything that fuel or air flows through should be cleaned and checked. Sometimes a can of cleaner will not do the job. 
Parts should be visually cleaned and verified prior to assembly. OEM kits will always include ALL parts necessary for a proper rebuild vs aftermarket kits. Try to stay with OEM. 
Why the tirade? Because when you are dealing with a 2-stroke anything other than a full and verified cleaning can result in a lean condition that can destroy a powerhead or at least a cylinder. Clean 80% of a high speed jet and what do you have? A recipe for disaster. 
So....when you (anyone reading this) say you have cleaned your carb.........have you really? If you take the time to read through tons of posts here you will see that all too often carbs that have been cleaned have to be re-visited a second and possibly a third time to get it right.


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## Fordracing2105 (May 24, 2015)

Well I just I can add to this to help others. When I rebuilt my carbs before I got help from Pappy. I soaked than poked shot carb cleaner through every hole I could find. I could physically see light through my hs jets. But there is kind of a void behind those jets on my carbs where crap was built up and I assume fell and blocked later on.


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## Triple obsession (May 24, 2015)

An ultrasonic cleaner can be a mans best friend when cleaning carbs.


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