Johnson 15hp 2-stroke high pitched noise then stopped working

[catfighter]

Hello - sorry I haven't posted in a while but that's just cuz I haven't had any problems! Hopefully you guys can help me.


So my 1983 Johnson 2-stroke 15hp motor was running fine for years. then I noticed a high-pitched noise (like a VW beetle muffler, almost) coming from the motor but only when going forward and only with the throttle engaged.

I thought it was all in my head (as I exhibited it to other people and they didn't seem to notice anything wrong, not that they were any smarter than I . . .).

Then the motor started missing, then it slowed down and i could hear this ugly screeching sound (like a slipping belt, but it doesn't have a belt) coming from the motor. I put it in neutral and it stopped; I haven't tried to start it again.


here's some things I do know about it:


- The fuel mixture is 48:1 (or 16oz bottle of marine oil to 6 gallons of 91 octane fuel).
- I changed the oil in the propeller last year but I didn't this year (I think that might be the problem!!)
- The water from the stream (I call it the "pee stream" hehe, the little place where the cooling water comes out of the motor) was warm but not hot.
- the high-pitched noise sounded similar to a VW beetle exhaust, high and tinny, it otherwise sounded normal.
- it wasn't running all that great. Normally I could go 15mph with 2 ppl in the boat but it was running around 5mph. I was stuck far, far away from my car w/ no one around so I had to run it . . .
- I did not have the motor tilted; w/ 2 people it runs fine if it's almost perpendicular to the transom (and it still planes, yes).


Thanks in advance for the help; hopefully i didn't just destroy the outboard cuz it's been a great motor these past 3 seasons. . . .

 

[milliesdad]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

Sounds like the motor siezed. Try turning it by hand. If it won't, remove lower unit and try again. If it still won't budge, time for a teardown.

 

[nwcove]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

i agree with milliesdad, usually that high pitched ....slipping fanbelt sound......is metal on metal. even with the proper fuel oil mix, a carb problem can lean a motor out and cause big probs. will it turn over in neutral? pull the plug wires off and try turning the prop in neutral (make sure wires are off!... i had one start up just by turning the prop to compression stroke!) you should be able to isolate where the problem is.

 

[Rick.]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

Did you see the tell tale stream when it was screeching? Your pump may have stopped functioning or your intake may just have been blocked. It does sound like an overheat to me but hey these are very forgiving motors. Put it in a barrel and give it a go to see what's happening. I am assuming it is freed up now that it's cool? Best of luck. Rick.

 

[catfighter]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

Did you see the tell tale stream when it was screeching? Your pump may have stopped functioning or your intake may just have been blocked. It does sound like an overheat to me but hey these are very forgiving motors. Put it in a barrel and give it a go to see what's happening. I am assuming it is freed up now that it's cool? Best of luck. Rick.

I really appreciate the help on this.

Yeah, I tried to restart it (it's a rope start) and it turned over in neutral, so I don't think the engine is seized per se. I'm going to take out the plug and replace it. Is there a filter somewhere that should maybe be changed?

I have a book on this motor but if anyone has a quick troubleshoot kind of flowchart for me to go thru that would be very helpful. . . .

Thanks again!

 

[catfighter]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

UPDATE:

So I went out and tried to turn it over just now. It turns over but just barely, like one or two times when I pull the rope. In neutral with throttle closed and WOT, and in fWD with trhottle closed, it just barely wants to turn.

But it does turn.

I'll hopefully get to hook it up in a barrel tomorrow and mess with it some more.


BTW - regarding the carb being messed up, I only use 91 octane, I use marine/boat oil, and I never put the motor away with gas in the carb (i.e. I always pull the hose out and burn what's left of the gas fumes in the carb before I put it away). I heard that's the best way to keep things clean. I usually buy Evinrude XD30 but I bought some blue brand while on a long trip. . . still 48:1 ratio. I hope that isn't the problem!

 

[Rick.]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

http://forums.iboats.com/showthread.php?t=158071
Have a look at this from the Top Secret File at the beginning of this forum. You should be using TCW3 oil. Rick.

 

[catfighter]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

http://forums.iboats.com/showthread.php?t=158071
Have a look at this from the Top Secret File at the beginning of this forum. You should be using TCW3 oil. Rick.

I called the place where I got the oil; they have 2-cycle outboard (TWC3) and 2-cycle universal. I can't imagine grabbing the wrong one.

 

[catfighter]

UPDATE on Outboard Seizure

UPDATE on Outboard Seizure

Okay, so for all of you interested in my outboard tribulations, here's an update:

1. engine

I replaced the old spark plugs, which looked carbon fouled but not terrible-looking. They look like 2-3 year old plugs, actually. I can turn the fly wheel by hand pretty easily but it gets "stuck" sometimes. When I tried to start it as normal, there was ignition and it would turn over 5-10 times and then die. After that I tried to turn the fly wheel and it was stuck unless I turned it in reverse, then it would un-"stick" itself. There was also a screeching type noise when it ran, sounded kind of like squeaky bicycle brakes.


2. Checked Gear Oil:

The gear oil needed changed but there wasn't any water in it, it also didn't have that milkshake look to it, which is indicative of water intrusion. It did have a pea soup look to it and smelled a little burnt. I replaced it with SAE 90 lubricant from my local boat shop.


3. Lower Unit

I removed the lower unit thinking that might be the problem with why it isn't starting. I can turn the crankshaft by hand and it turns the propeller. Ergo, I don't think it's seized or there is anything wrong with it. Let me know if this "check" is inaccurate and if you think there still might be problems here (and how else to check properly). Also the shift connector was broken so I have one of those ordered (actually glad I caught this now and not on a lake somewhere!!).




Please let me know what I should do at this point; am I left to resort to getting something fixed by a mechanic or does all this sound promising to you? I'm at a loss as to where to go from here. :facepalm:


Thanks a lot!

 

[Rick.]

Re: UPDATE on Outboard Seizure

Re: UPDATE on Outboard Seizure

This does not sound good to me. Turning the flywheel clockwise, it should not stick and require a counter clockwise rotation to unstick it. I guess at this point you could do a compression check but I think your going to have to take your motor apart to diagnose the problem. Hopefully some one who knows more will chime in here. Rick.

 

[catfighter]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

Thanks for the insight; I hope others chime in as well.

I'm at a crossroads now anyway, seeing as I was going to buy a 25hp eventually. I would really just like to get it running and then sell it for proceeds toward a 25. I guess I could do that now but I would really like to know what's wrong (seeing as the next motor I get will probably have an issue or three).

 

[trendsetter240]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

Does the engine still bind with the plugs out? Try pulling the plugs then cranking it over. If it still sticks as you described or you hear any "screeching" noise then you need to pull the head off and take a look in the cylinders for damage.

If it still binds with the plugs out and you can't see any damage in the cylinders then my guess is a bearing has failed. Connecting rod or crank bearing. If that's the case the powerhead needs to come apart to find the problem.

 

[catfighter]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

Does the engine still bind with the plugs out? Try pulling the plugs then cranking it over. If it still sticks as you described or you hear any "screeching" noise then you need to pull the head off and take a look in the cylinders for damage.

If it still binds with the plugs out and you can't see any damage in the cylinders then my guess is a bearing has failed. Connecting rod or crank bearing. If that's the case the powerhead needs to come apart to find the problem.

I will do this and let you know.

Thanks!

 

[catfighter]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

There are 3 outboard repair shops near my house (and by "near," I mean less than an hour away). 2 shops said they won't even look at my outboard b/c it's so old and the third said they would charge me $200 before they even look at it to tell me what it needs.

Is this par for the course in outboard repair? If this is the case, I'm probably just going to sell the lower unit and buy another one if I can't figure this out on my own. . . .

 

[Jim311]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

Well from their viewpoint, lets say you drop that motor off and ask them to inspect it and tell them what's wrong. They put a few hours of labor into diagnosing it or whatever, and come back at you with an estimate for the repair that will more than likely exceed the value of the motor. Then you just leave the motor there or probably balk at the repair estimate because the repair is near what a new motor will cost, and just leave the motor and them with their unpaid labor charge. That's why a lot of places won't even work on older stuff. My suggestion is to drop the lower and make sure that the lower unit isn't locked up. If the motor were seized I don't see why you'd be able to turn it a quarter of a turn before it stopped. It has no valves so it's not like that's an issue. I'm thinking maybe something is seriously damaged in your lower unit preventing the motor from turning. It wouldn't take long to drop the lower unit. From what I've read damaging bearings on these motors isn't all that likely since they're lubricated by copious amounts of oil in the fuel. Anyway, I may be way off base with these assumptions but it's seven bolts to drop the lower so it's worth a try. It may just be a locked up lower unit.

 

[catfighter]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

Well from their viewpoint, lets say you drop that motor off and ask them to inspect it and tell them what's wrong. They put a few hours of labor into diagnosing it or whatever, and come back at you with an estimate for the repair that will more than likely exceed the value of the motor. Then you just leave the motor there or probably balk at the repair estimate because the repair is near what a new motor will cost, and just leave the motor and them with their unpaid labor charge. That's why a lot of places won't even work on older stuff. My suggestion is to drop the lower and make sure that the lower unit isn't locked up. If the motor were seized I don't see why you'd be able to turn it a quarter of a turn before it stopped. It has no valves so it's not like that's an issue. I'm thinking maybe something is seriously damaged in your lower unit preventing the motor from turning. It wouldn't take long to drop the lower unit. From what I've read damaging bearings on these motors isn't all that likely since they're lubricated by copious amounts of oil in the fuel. Anyway, I may be way off base with these assumptions but it's seven bolts to drop the lower so it's worth a try. It may just be a locked up lower unit.

I dropped the lower unit; I can turn the shaft by hand and it turns the prop. So it's not the problem. Maybe I'll just buy a 25hp Johnson and use this one for parts or something. I'm going to start tearing it down now; I'll let you guys know what I find (of course).

 

[the machinist]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

With the cowling off inspect the block (in the arrea usually behind the fuel pump) for cracks in the block. You could have had a ring gland break allowing a chunk of the top of the piston to be sucked into inside of the block & get caught at a narrow spot breaking the block. If so chunks of aluminum can be floating inside. Not Good

Also pull the head & the bypass cover (the cover on the LH side of the motor) This will let you see the top of the pistons & with the cover off you can view one side of the pistons for damage.

 

[Tim Frank]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

Never turn a small 2-stroke O/B backwards...it can mess up the impeller blades.

 

[catfighter]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

Well, I see why the guy wants $200 to inspect the engine. It's like a car motor, shrunk to 1/10th the size and crammed into a greasy metal box. It's driving me batty.

For instance, the throttle is in the way of the retaining bolt on the carb and I cant get to it, and I'm afraid of destroying the throttle in the process.

I need a puller kit to pull the flywheel (?!)

By the time I'm done tearing this down, I will have saved enough money to buy a new one. . . .

 

[catfighter]

Re: Johnson 15hp 2-stroke high pitched noise then stopped working

Never turn a small 2-stroke O/B backwards...it can mess up the impeller blades.

The impeller is in the lower unit, right? I have removed the lower unit at this point -- not that I have made a habit of turning the flywheel backwards. . . .