1995 2 stroke 115hp Problems

[fishboarwakerider]

Hi, i just recently purchased a 17 ranger R77 with a Yamaha 115hp outboard. It's been running like a champ for about 5 days out on the water until today.

Today at the end of the day it started to die while it would be idling. No problem.. start it up, give it a touch of throttle, then be on my way. Now, I'm using this boat for wakeboarding, so it's getting alot of dead stop to full throttle launches leveling off at 3400rpms and cruising at 18mph.

By the end of the day.. it was having trouble staying at idle, and when taking off it sounded like it was running on only 3 cylinders at first, then just all of a sudden runs smooth like nothing is wrong. But when you let off the throttle, it would die. Sometimes it would need to be choked to get it started again.

I pulled the plugs and they were kinda loose and the right 2 cyl had a little oil leaking from them. The plugs are fairly dirty and I'll be replacing them tomorrow. If it isn't the plugs being somewhat fouled... what else could this problem be?

It's progressively getting worse as the day went on today... and someone on the boat said it sounded almost like 1 of the coils was goin out and not firing or something.

Anybody got any ideas I can try without having to take it to a shop yet.

[slim]

check the fuel filter on the side of the powerhead. its almost right under the oil tank. unscrew the bowl and check for water. if you dont know if its water or gas, pour it on some concrete. water will stay in a bubble and gas will spread out and soak in immediatly. if there is water in it, your gonna have to tear down the carbs and fuel pump. blow out real good with compressed air. replace the carbs on the motor and resync. this should do it. you should invest in a fuel water seperator. make sure you get one that is 10 microns.

[Ken]

'rider,
Could be just dirty plugs - you need to replace them once a year anyway on a 2-stroke.
Also, could be clogged low speed jets. I would try a shock treatment with SeaFoam or RingFree first - sometimes this works. If not, then try removing as many jets and drain plugs on those carbs that you can get to and squirting something like Berryman's Chemtool into the orifices. Sometimes this works.
If none of the above helps, then probably time to tear down the carbs, clean, and install a carb kit.
Also, your idle speed, in neutral, should be around 700 rpm - may need to adjust it.
Good luck, and let us know how you come out [img]smile.gif[/img] ,
Ken K

[fishboarwakerider]

Ok I took out the plugs today, and they looked like they were fouled fairly bad. Bought some me NGK-R BR8HS-10's and gapped them to .040 and will be taking the boat up to the lake for some tests.

The Fuel filter was very clean and free of water. Also there is a Raycor before the engine and the bowl in that was good as well. Hopefully this is just a simple case of the plugs. I'll post later tonight with results.

Also, the idle before any of this was at 750 dead on and smooth, but slowly was progressing to this situation of dieing over the last 2 day trips of wakeboarding at about 6hr's per day.

Last night when it started happening as we were getting done and about to head towards the dock.. it was still idling at 700rpm's but would sort of cough then die.

When I go up today and run it, I'll bring a digital camera and take some short ****** so you can hear what it's doin.

[Bluebird]

Carbs,Carbs,Carbs. Buy some berrymans chem tool,remove the low speed jet screws,spray the straw of the chem tool in each, then do it again. reinstall the idle jet screws. You do have the manual to tell you how many turns out from soft stop on the screws right?
That should do it until it happens again, after you get it cleared up replace the whole racor setup base and cartridge with the 10 micron one.