1986 15hp yamaha

[kei9th]

i just bought my first jon boat. it can with a 1986 15hp yamaha outboard. when i first took it out oi ran great. i accidentally ran it out of gas. after doing that i have no power at WOT . i cleaned the carb and change the spark plugs. everything seemed to work well when i ran it at home. while out in the canal when i twist the throttle wide open it dosent have any power and it dosent seem to respond at all. if it does get up to high enough rpms it seems to be struggling, idles fin and runs at half throttle well. i only have on adjustment screw on the outside of the carb. i think thats just for idle. any suggestions

 

[Rick K]

Re: 1986 15hp yamaha

Keith,

You indicated you just got the boat, etc., and it ran great until you ran it out of gas. If you don't know the history of the motor, buy a rebuild kit for the carb, and some new fuel pump diaphragms, and do those too. More importantly, change the impeller in the water pump.

Also, short of spending alot of money on a service manual, a Clymer book will suffice for basic maintenance.

These motors are die-hard-work-horse-battle-wagons.

Kept properly tuned and maintained, it'll start on the first pull every time.

iboats sells everything you need...

Hope this helps.
Rick

 

[kei9th]

Re: 1986 15hp yamaha

i changed the water impeller before i put the boat in the water the first time. i dont know really anything about boats but i was told that is the most important thing. is there a down loadable manual from the internet only because in the life and times of now who wants to sift through a book? i am more than willing to pay for it as i have only seen them in paperback models. i have cleaned the carb but getting a rebuild kit and fuel pump is a good idea? thanks ill try that. also what about decarboning the motor as i have read today?

 

[Rick K]

Re: 1986 15hp yamaha

Keith,

Do a search on ebay for "yamaha outboard service" and there's some there. Mind you, I have no clue what's in 'em, or if they're worth the paper they're printed on, and don't endorse 'em.

You said you cleaned the carb. If you didn't tear it down and rebuild it, then you didn't clean it properly. NOT trying to be a know-it-all, but if the motor sucked up a bunch of gunk, cleaning it with carb cleaner isn't gonna do it. I believe you want carb kit# 18-7769, which you can get here. You didn't mention the model number of your motor (which you should always do when posting a question), so don't quote me on that part number.

Personally, I prefer genuine Yamaha Parts, and I didn't see one listed here. Not sure where you're from, but by me, my Yamaha dealer has pretty much the same prices as anyone online, so I just grab those parts.

If you want to see blow-up diagrams of your motor, go to yamaha's website, www.yamaha-motor.com/outboard and go into the parts and service section. The rest is self explanatory.

Last, search these forums and read read read! There's more information in here than a truckload of manuals could ever provide! But ya still need one...

Rick

 

[kei9th]

Re: 1986 15hp yamaha

thanks rick i ordered the carb rebuid kit and a fuel pump diaphram. this website does have a wealth of info, i probably read through about 85 pages yesturday. thanks for all the info when i get the parts and get everything rebuilt i will post. thanks

 

[Rick K]

Re: 1986 15hp yamaha

Glad to hear you're heading in the right direction. As I said, these smaller Yammy's are pretty straight forward and simple. One of the main things anyone here will tell you, is that when you don't know the history of the motor, is to go thru it, and make sure everything's up to spec's.

You might want to do a compression check (search for that on here) as well, although something tells me it'll just be for piece of mind...

Barring anything else, I would think you wouldn't have anymore problems after gettting the fuel system cleaned up.

I once futzed with on old Johnson for days, before I realized that I forgot to pressurize the tank... DUH! And I didn't even catch one line of ridicule over on that forum...

But hey, if we were all perfect and knew everything, this forum wouldn't exist!!!

Good luck
Rick