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

[NathanY]

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

Did you check under the flywheel to see if one of the magnets came loose?

 

[Tim Frank]

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

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. . . .

OK, but I was simply going by what you wrote in your opening post.
According to that, you didn't drop the L/U until step # 3....you were turning the flywheel backwards in step#1.

 

[nwcove]

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

geez......remove the head, have a look...post pics of the cyl walls and inside the head.....sounds like a meltdown to me!

 

[catfighter]

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

geez......remove the head, have a look...post pics of the cyl walls and inside the head.....sounds like a meltdown to me!

I finally got disgusted trying to take this thing apart (it's harder than it looks, apparently), so I took it to a guy who was referred by two people I know and is reputable. He said the powerhead is cooked; the one cylinder has 50PSI and the other one has 9 (nine) PSI, and that it's not worth fixing. He wants $65 for taking a look at it, which I'm happy to pay.

Here's my question: what do I do with this thing now? Should I ask if he wants to just keep it and call it even? Or should I pay him, take the motor back, and try to part it out? (for instance, it's a brand-new propeller, and the L/U is in good shape . . .)?

Or is that a total waste of time?

Thanks for your help on this. My wife told me no more 25-year-old outboards; I have to buy new (or like-new) motors now. She's so unreasonable! ;-D

 

[raczekp1]

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

i would take out the head,and look into cylinder holes.
if it is scored badly even very badly-sel motors for parts
if wals are not badly scored:
-pull of flywhel ,take out powerhead, dissasemble powerhead,
rebore cylinder holes for oversize pistons and rings,order oversize rings and pistons, and gasket set.
put things into powerhead and do the break in
you will get almost new motor.
here is a good guy-the mechanit, he can help you a lot with this.
all parts are avilable so spend 200$ and you will have almost new motor

 

[catfighter]

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

That's what I was thinking, actually. I mean, I'm glad that it's just a toy at this point. I can even wait until next year (and probably will) to buy another outboard. By that time I can put $200 in this one and maybe have it up and running w/out having to pay $2000!

I'll bug Mechanit and see what he says.

 

[AEROCOOK]

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

I finally got disgusted trying to take this thing apart (it's harder than it looks, apparently), so I took it to a guy who was referred by two people I know and is reputable. He said the powerhead is cooked; the one cylinder has 50PSI and the other one has 9 (nine) PSI, and that it's not worth fixing. He wants $65 for taking a look at it, which I'm happy to pay.

Here's my question: what do I do with this thing now? Should I ask if he wants to just keep it and call it even? Or should I pay him, take the motor back, and try to part it out? (for instance, it's a brand-new propeller, and the L/U is in good shape . . .)?

Or is that a total waste of time?

Thanks for your help on this. My wife told me no more 25-year-old outboards; I have to buy new (or like-new) motors now. She's so unreasonable! ;-D

If it were mine I would find another used 15hp of the same era thats working well and keep yours for parts. Theres always a degree of risk involved when buying a used motor but you can minimalize the risk by having the motor inspected prior to purchase, a compression test is a must.
As for not buying another 25 year old motor, I would much rather buy a 25 year old motor that was well maintained than one even 2 years old that was wasnt and the older one will be cheaper too so you shouldnt be too detered by age.
Just my 2 cents worth.

 

[catfighter]

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

to me, it makes perfect sense. to my wife, on the other hand. . .

I'm going to try to fix this one; we'll see how far I get and make the decision later. Luckily I have several options when it comes to fishing, and my boat is small enough that I don't even need the o/b to use it. The trolling motor scoots it along pretty well, as long as I'm going with the river current.

 

[catfighter]

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

UPDATE -

I tore down the motor to the power head. Here are some pictures:

Does this look salvageable to you or should I not waste my time? Could I get away with just doing a ring job here?

http://a2.sphotos.ak.fbcdn.net/hphotos-ak-ash4/224442_10150277477036730_689756729_7650079_3542175_n.jpg

http://a5.sphotos.ak.fbcdn.net/hphotos-ak-ash4/185326_10150277477546730_689756729_7650081_6307951_n.jpg

 

[AlTn]

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

do the cylinder walls show much scoring?..will a finger nail "snag" on any grooves or score marks?...if all is fairly smooth, and this motor were mine, I'd remove<"scrape"> as much carbon from the head as I could, piston tops as well, surface the head, replace the headgasket, and rebuild the carb...it looks as though it's been used for trolling a lot or the carb is set on the rich side....agree that pulling the f/w and seeing what might be rubbing there would be a good start...if you find a crankshaft bearing is failing, then other decisions will have to be made...but just from the head and piston photos, you don't have much of a problem

 

[catfighter]

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

Thanks for the help AlTn. The cylinder walls are pretty smooth, actually. I should have also mentioned that the lower (charred) piston has more play in it than the top one. That's why I think I may need a ring job. Also, if you twist them in the cylinder they both move maybe 5 degrees or less I figure they're supposed to do that.

I bought this used, of course, but I actually didn't troll much with it. Mostly WOT for 20 minutes at a time to get somewhere and then park it. I thought that may have been what killed it. . . .

 

[OptsyEagle]

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

By the way, when you get this fixed or buy a new motor, stop running it dry of gas. I cannot say that this added to your problem since many people do this, but when you run a two stroke dry of gas you also run it dry of oil. Over time the inners start to corrode and possible failure can result.

If you are worried about fuel gumming up use a fuel stabilizer. Seafoam is the best, but any other will do. Just my opinion.

 

[catfighter]

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

This makes sense; I will try a fuel stabilizer.


Does anyone know how to remove the lower cover from the motor? I can't seem to figure it out (and I'm a reasonably intelligent person. . .). Or does it not usually come off?

 

[raczekp1]

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

i think everything is ok in this powerhead, just put new head gasket, do the head flatening in auto repair shop and bolt things back.

i think buying next motor you just run in next unknown world.

do the job with this one. you have good compresion.
unbolt side cover to look into cylinder wals and pistons wals.
if everyting is ok, just order head gasket, and gasket under side panel and bolt back everything

read LeeRoy Wisner Ramblings very careful and do the job.
you live in us and every new part to this motor is avilable, just order and do the job

to remove lover cover you should:
1. take our rewind starter,
2. unscrew lower coil, and powerpack, take them out.
now you will see 3 bolts(one under rewind starter suport, under powerpack, and lower coil)-unscreav and take them out.

unbolt lower unit, shift conector inside midsection and take out lower unit,

powerhead is bolted to mid section by 6 bolts(2 londer une just under head area, and 4 shorter one)
unscreav this bolts.

use crovbar or tire hijack to lift powerhead, sometimes just tilt side to side a powerhead.
under powerhead is a gasket, and while using motor this gasket just burn out and act as a gleue. the idea is to break tension

 

[catfighter]

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

thanks for the help. I found those 6 bolts. . . I'm actually interested in just taking the powerhead out (everything else can stay in place as far as I'm concerned) B/c I need to clean it and inspect the pistons and likely replace the rings.

what [else] needs removed to remove the powerhead besides those bolts and the fuel lines?

Sorry if I'm being a pain. I'm officially getting discouraged at this point because I can't even find a 2-stroke mechanic near me, and I live in West Virginia . . . .

to remove lover cover yo should:
1. take our rewind starter,
2. unscrew lower coil, and powerpack, take them out.
now you will see 3 bolts(one under rewind starter suport, under powerpack, and lower coil)-unscreav and take them out.

unbolt lower unit, shift conector inside midsection and take out lower unit,

powerhead is bolted to mid section by 6 bolts(2 londer une just under head area, and 4 shorter one)
unscreav this bolts.

use crovbar or tire hijack to lift powerhead, sometimes just tilt side to side a powerhead.
under powerhead is a gasket, and while using motor this gasket just burn out and act as a gleue. the idea is to break tension

 

[raczekp1]

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

read back my post.i just updated some words.

i think the best knowledge you just find in LeeRoy articles and good hand in forum.
use digital camera to help yourself while botling back.

you also shold unbolt shift tension mechanizm.(when you move shift hendle, this black plastick mechanizm moves)
one bot holding this black piece of plaskick, just in fuel pump area.
just undolt this biger bolt( 8mm bolt head)

 

[raczekp1]

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

http://www.youtube.com/watch?v=cqYiFl6I_20

http://www.youtube.com/watch?v=jd8WC98JGCI

and watch next movis

 

[AlTn]

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

along with the great advice given by raczekp, an omc factory manual giving tolerances and torque values is a good thing...if you're willing to deal with ebay sellers...a known good powerhead may be an option as well

 

[catfighter]

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

Holy cow, thanks Raczekp1! These vids will be helpful.

AlTn- I was thinking about that; it really doesn't look bad at all, imho . . . I'm going to do a tear-down first and hopefully try to fix it myself. If it looks futile I might pick up a used powerhead.

 

[catfighter]

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

OKay! so I got everything apart. . . not nearly as difficult as I suspected.

The one issue I'm having is separating the two parts of the crankcase to see the crankshaft. I can't seem to find a place to pry on it. Plus, what do I do with the dowel pin keeping the two pieces together?

Also, there's no gasket connecting the two? That seems highly unlikely.

Thanks for any help in advance; if you need pics let me know and I can post'em.