Repair or Replace 15 hp johnson? What to do?

SpinnerMan · 05-22-2003, 12:07 PM

Have an '85 15 hp johnson that I've had since new. I had it in the back of a pickup about 10 years ago and it slide forward and damaged the throttle control (it is in the handle). The damage made the handle very hard to turn and give the motor gas. [img]graemlins/dork.gif[/img]

I didn't use it for 3-4 years and just tried the motor on my new drift boat and found I could start it and it would idle fine, but I could not give it gas at all. I used it on the idle speed for 8 hours and had no problems, it still runs great -- just could not give it any additional gas. :depressed:

We took it to a dealer who said it would be $75. just too look at it and tell me how much it would cost to fix it.

What would you do? :whazzup:

Thanks in advance for your input.

SM

jimh · 05-22-2003, 12:28 PM

I'm assuming that it dies when you give it gas.

I'd clean the carburator either by taking it apart or by buying some fuel additive carburator cleaner. Use the whole bottle that usually goes for 20 gallons and mix it in about 1-2 gallons of premium with new 2 stroke oil making sure that you don't mix it too rich. Then, clean the air filter and replace the spark plug(s).

I doubt that any mechanical problem exists and that it just a fuel system problem with varnish. It may take 30 minutes running, or so to clean it out.

If that doesn't work, then take it to a shop.

N7754H · 05-22-2003, 01:07 PM

you may also have a spark advance problem, these are simple mechanical advance systems and it could also be gumed up lube everything that moves under the cowl, and remove the carb and both jets and clean them in a dip tank. If you don't have the know how i would suggest having it done the motor is worth keeping.

ampersat · 05-22-2003, 02:34 PM

i've said it before and i'll say it again: if you can work on a lawnmower, you can work on an outboard, and anyone can work on a lawnmower.

first, get the manual. if you don't want to buy the book, chances are good you can get it from your local library.

second, find a good place to work on it. you need plenty of room to spread out all the parts you're going to remove. try to keep the parts in some semblance of order according to how it came apart. it'll make it easier to remember which parts go together when you're reassembling. keep the manual nearby (you did get the manual, didn't you?) where you can refer to it often but not get it filthy.

third, grab some screwdrivers, wrenches, sockets and the like and start disassembling. the tiller handle is either going to be shaft driven or cable driven back to the powerhead. either way, once you remove some of the outer stuff and can see the working parts, you'll see what's broken. heck, it may not even be broken. you might have a pinched cable or a linkage that is bound up.

most motors can be converted to remote controls (eg, steering wheel and lever as opposed to tiller) so i'm guessing the tiller handle will come off as an assembly fairly easily. actually, once you get the tiller handle off, you should be able to determine whether the handle is the problem or it's somewhere in the area of the powerhead. from the sounds of it, it's the tiller handle .

$75 is a little steep in my book just to find out what might be wrong with it. if you get the tiller apart and can't seem to figure out what's wrong or you reach a point where you feel you're in over your head, you're no worse off for having disassembled it because that's what the tech at the shop is going to have to do anyway. if you do end up having to take it to a shop somewhere, call around first. there have got to be some better deals out there.

craigc · 05-22-2003, 03:50 PM

I have a 15hp Johnson of a close vintage... You speculate the handle is the reason for your inability to change the throttle and engine speed... since this isn't brain surgery, I'd look at how to dis-assemble the throttle handle assembly and rotate the rod that the handle rotates... if you find the rod rotate easily, I'd look at the parts to see which has been damaged and get it repaired or replaced.... If not, I'd look further into the engine to see what is binding..... good luck, Craig

SpinnerMan · 05-23-2003, 03:12 AM

Very good idea Craig. That is what I'll do -- thank you. And thanks to the rest of you also.

SM

[ 05-23-2003, 04:14 AM: Message edited by: SpinnerMan ]

Nodakr · 05-23-2003, 05:04 AM

Spinnerman,If you find out that it is your handle that is causing the problem,send me an email,I have a motor about that same vintage I picked up at a garage sale that I was planning on fixing up but haven't.The o'l guy I bought it from said it ran fine last time he used it.I would let it go for 50.00 bucks (that's what I paid for it) good luck!