1990 90hp johnson outboard

" I just had the head gasket r

" I just had the head gasket replaced by an outboard mechanic because my 90hp johnson was running rough, smoking alot, and oil was coming out of the upper unit area. The mechanic replaced the head gasket and i thought it would be fixed.

However, when i took it out last night it would very hard to start, had to be taken out of gear and reved for about 5 minutes before it finally settled down. Then when i would slow the boat of a plane it would stall. It used to run fine, but now its nearly impossible to keep running.

I think theres another problem but im not sure what it might be. The gas/oil is the same mix from my last trip where the boat ran fine, so i kinda elimate the feul supply.

It shakes the boat, and smokes alot, anyone got any advice as to what it may be? "

"Steve.... Althought your mech

"Steve.... Althought your mechanic replaced a head gasket (which one?), you don't say why he replaced it. What explanation did he give you for removing the cylinder head in the first place?

Regardless of the problem, it's always best to start troubleshooting by checking the compression which should be in the range of 100+ psi and even on all cylinders. Then (with the s/plugs removed), check the spark which should jump a 7/16" gap on all cylinders.

If the above checks prove to be okay, especially if the engine has been sitting for a few months, it's very possible that the carburetor(s) are fouled. If so, the cure would be to remove, clean, and rebuild them. Let us know what you find.

Joe "

" I am no mechanic so i dont k

" I am no mechanic so i dont know to much and could be suckered easily. But hopefully, my mechanic wont do that, he actually seems helpful, and knowledgeable.

Initially the engine stalled in the yard after running fine the trip before and then a couple of minutes in the yard. Since that time, it is hard to start, must be out of gear, and reved for a few minutes before settling down to a shakey idle, if i lower the throttle it would stall.

The first trip to the mechanic, he sees oil leaking from the bottom of the cawling and says its probably the head gasket. $160 later i have a new head gasket and think im good to go.

I take the boat out the next night, put 2 extra gallons of gas into the 8 that are already there hoping to thin out some of the oil that seeming to be burning. But the same thing happens, hard to start, and stalls when i lower the throttle. It seems as though the gas/oil is not being burned properly.

So i take the boat back in the next day, tell the mechanic i dont want to spend any more money on the motor other than an hours worth of trouble shooting including a compression check.

He calls me back and says hes found the problem. A bad ignigtion coil. A small plastic-looking black piece off one of the cylinders about 2x1 inches in length. He says the boats been running mainly on 3 cylinders. He also says the compression test came out at around 125-130 for all four cylinders and looked ok(cylinders were bored out and enlarged years ago). He also said he used a seperate gas tank and it may have run a little cleaner but about the same.

I then notice that theres a good amout of oil coming out of the prop area. I asked if it was normal and he said not really but because it was running on mainly 3 cylinders it had to burn it out. So i asked him if it would stop and he said it should.

So i take it home at lunch and try to run it there. Once again its hard to start and smokes more than it ever has. I am frustrated and dont know if i should take it to a different mechanic, back to him, or give up on it. It was only $70 for him to look at and replace one of the ignition coils, but my pateince is wearing thin. I wish i could get it looked at and get the right answer as to why it still runs so rough.

I will try to take it out tonight and run it again but i dont have good expections after running it in the yard.

Joe, thanks for the advice. the boat has been sitting for about 6 weeks but has been run every week or two. About, how much would it be to remove, clean, and rebuild the carbs. And after hearing the latest info, is that where you lean?

thanks,
Steve "

"Steve.... From what you'v

"Steve.... From what you've had to say in the above post, I doubt very seriously if the carbs are at fault. It's possible but not likely.

Without bad mouthing your mechanic (something I try to avoid as we all make mistakes), I suggest that you find a more knowledgeable person to check your engine over, as a couple hundred dollars later, you are no better off.

A engine that is having a problem such as you describe, one that shows up even on a flushette, not an intermitent problem but rather one that is constant and steady, should be easily diagnosed.

If you should be in the Tampa Fl area, let me know.

Joe (30+ Years With OMC)"

" You may have a flooding carb

" You may have a flooding carburetor. Is this VRO equiped or regular older pump? Is the start primer sticking ,working at all? "

" Joe isn't going to say i

" Joe isn't going to say it, but what the hell, I will. I'd think it would be pretty hard, for anyone that calls themselves a mechanic, to mis-diagnose an engine consistently not running on all cylinders. If the problem was intermittent, and it somehow ran fine at the shop, that's a pretty standard situation, and could happen to anyone. If you brought your boat to a larger shop, sometimes the person who act's like they worked on it really didn't and the info you will get is second hand - another possible situation.

The oil dripping down the exhaust housing, coming out of the prop, means very little. If an engine was not running on all cylinders, or had poor spark, it would be worse, but running in cold water or long periods of idling or humid weather/bad fuel all could cause the same symptom.

If the oil was dripping from somewhere under the cowl, it should be pretty easy to determine where it's coming from. Did he/she mention anything about compression? You can run these engines at double the oil/fuel mix and it has little effect, so as you stated, it's probably not fuel.

My unproffesional guesses would be (some have been stated allready), assuming compression is good. An issue with the primer, VRO, or a problem with something central to the ignition system.

Jon "

" Damn you guys are good. I t

" Damn you guys are good. I tried to take the boat out Friday after it had already been looked at twice. The first time the mechanic may have tought the only problem was a worn down and breaking up head gasket which was replaced on the first trip.

The second trip in, he replaced an ignition coil, which he said was only letting the boat on 3 cyclinders, i believed him and hoped for the best. He also did a compression check which came out ok, checked the sparks, etc.

Well on friday i took the boat out and it had the same problems, ran rough, hard to get started, smoked alot, and stalled when i brought it off a plane. So i took it back in, and he took a look at it for the 3rd time. He found out that the choke was always on when the boat was turned on at the ignition. The engine was getting was too much gas thus causing the problems of it hard to start,stalling, and running rough.

He took a close look at the ignition switch on the boat and SOMEHOW there was a wire that when he disconnected it stopped the constant choking. The kicker is the boat had been running fine for the past 6 months, so i dont know how all of the sudden the motor is getting choked when started. Maybe the switch went bad or something not sure, but it fixed the problem. Thanks for all the great input.

Steve

ps. friday after the mechanic fixed the boat my brother and i went out and still managed to catch and release 1 sailfish out our 18 ft. 1973 hewes flats boat with a 1990 johnson 88special. "

"Steve..... That 1990 90hp Joh

"Steve..... That 1990 90hp Johnson does not have a choke, it has what is called a fuel primer solenoid. When you push the key in, the solenoid opens and allows fuel to be forced into the intake manifold just in back of the throttle butterflies.

If the engine ran fine previously, and the fuel primer operated normally (and nobody had made any modifications), then suddenly the fuel primer solenoid remained in the open position, that would be due to having the ignition switch short out, throwing a constant 12 volts to the terminal that operates the primer solenoid.

Removing that wire from the ignition switch would cause the primer solenoid to be nonfunctional which should result in one very hard starting engine.

Do this.... With the hood removed and the ignition key in the on position (engine not running), push the key in to energize the primer solenoid. If the primer solenoid is working, you should hear a slight click right at that solenoid. It will be a dull click so listen closely.

If you do not hear that click, the primer solenoid is not operating due to having that wire removed. This would be due to having that wire removed and would indicate that the ignition switch is shorting out internally.

When the ignition switch starts to short out, it will eventually also throw 12 volts to the powerpack black/yellow wire terminal, and that will destroy the powerpack. Do the click test and let us know what you find.

Joe"

" Joe,

thanks for the repli

" Joe,

thanks for the replies. Thats the wierd part. no changes have been made to the ignition or electrical for almost a year.

I did your test, and did hear a slight click that you said would be there if it was working properly. So issume it is working ok.

I also had another question about the motor and was hoping to get some more advice.

The motor seems to drop in rpms just for a fraction of a second when on a plane, at least this is when i can notice it most. Its only for a fraction of a second and then runs fine for a while 5 mintues or so, and then you hear it skip/drop in rpms again. Im not sure if its fuel related, or electrical. Was wondering if youve come across it before. Thanks "

" Hello everyone.
New to the

" Hello everyone.
New to the forum.
Need help with 175hp evinrude.
New powerhead in 1993,approx 120 hrs total on new powerhead, dealer performs winterizing and spring tuneup etc.very happy with his work.
Last season i experienced problem when first out of slip after 15 min warmup time, engine would start to plane boat but felt loss of power, until something felt like it kicked in and motor picked up rpm and boat planed and took off as normal,called dealer he thought it was build up on hull after sitting in the water for at least a week in the slip.the last 2 trips of season when i returned from a day of fishing the motor would not idle smoothly, rpm changed intermittently. Is there anything i can check before i bring it to my dealer for the spring tuneup and checkout. "