Yamaha 60 FETO runs bad. (sneezes and dies out at idle)

[timberman]

Hi all,

Im having some trouble with my 1993 yamaha 60 FETO autolube engine. I bought this engine around a year ago and it already had some trouble when I first tested it out. It wouldnt go past 4000 RPM but I didnt noticed it since last week because I didnt had a tachometer.. But this is not the big problem atm, 2 weeks ago my engine had been under water for a short period of time. Directly cleaned it up, and got it up running again as it never even happened.

Now yesterday I tried out the engine on the water again and all went oke for 10 minutes, again the engine would not go beyond 4000/4100 rpm. After while the engine died when I had put down the throttle. Starting needed lots of choke and to keep the engine running I had to give it a choke every 4 sec or so, that was the only way to prevent it from dying.

Now I have taken apart the carburators again and checked the ignition timing and all seems ok, also replaced all 3 spark plugs. The fuel pump seems to be oke to so Im not sure what to check next. If im starting her up it will run with some open throttle but lowering the RPM will cause it to sneeze and dye quit fast.

Does anyone know how I can fix this problem? Can it be the CDI unit thats defective? (since it would go beyond 4000 rpm in the first place)
Hope to hear from you guys! Thanks in advance!

 

[99yam40]

Re: Yamaha 60 FETO runs bad. (sneezes and dies out at idle)

If the choke helps that means the carbs have fuel but it is not getting through the jets/passages properly. lean sneeze also says the same thing. Sounds like carb problems to me.

 

[timberman]

Re: Yamaha 60 FETO runs bad. (sneezes and dies out at idle)

@99yam40: Thanks for you reply. I have again dismounted the carbs and have put them in a fuel bath, and tomorrow I will use my compressor to spray some air through it again. Should I try some kind of carb cleaner to get them nice and clean?

 

[99yam40]

Re: Yamaha 60 FETO runs bad. (sneezes and dies out at idle)

I would have to say yes, carb cleaner will break down the stuff better or an ultrasonic cleaner does good to without harming the finish protecting the metal of the carbs.

What kind of water did it go under and for how long?

The internals will rust pit and destroy the motor in a very short time. Bearings and shafts do not like that kind of stuff

 

[timberman]

Re: Yamaha 60 FETO runs bad. (sneezes and dies out at idle)

Oke I will look for such a cleaner and give them a bath.

The engine has been under water for about 1 hour in freshwater. After it has been under I dry started it so most of the water was out, after that I sprayed lots of WD40 into the intake and all over the other places. Then I poured some 2 stroke oil in to the cilinders and put the plugs in and pumped the oil through and finally let the engine run for a while.. Hoped this all would prevent from giving it a chance to rust the inside..

 

[timberman]

Re: Yamaha 60 FETO runs bad. (sneezes and dies out at idle)

Got some progress with the engine. I cleaned out the carbs real good this time with some carb cleaner and there was some dirt in the what I believe are the idle jets.
After the reassembling the carbs it wouldnt run good either so we directly pumped fuel in to the carbs and excluded the fuel pump, the engine run alot better. Now I had borrowed my brothers fuel pump (from a 30hp) and the engine ran pretty good now and didnt coughed or anything like that.. Ordered a new pump and hopes that solves the max 4000 rpm problem to

 

[timberman]

Re: Yamaha 60 FETO runs bad. (sneezes and dies out at idle)

Hi again, im having some trouble with my throttle linkage at WOT. It seems that my throttle roller cant fully open the valves cause its not big enough so the valve opens up for like 90%.. You can see in the picture below that its not hitting the hard stop at the carb..

Here's a pic:

Anybody knows this is normal or am I having a worn out roller or something like that? thnx in advance!

 

[timberman]

Re: Yamaha 60 FETO runs bad. (sneezes and dies out at idle)

Anyone knows what wrong with my throttle roller/linkage system? I cant find any part number of the plastic pieces and Im not sure if it needs to be replaced..

 

[99yam40]

Re: Yamaha 60 FETO runs bad. (sneezes and dies out at idle)

what do the butterflies look like with throttle fully open?

 

[timberman]

Re: Yamaha 60 FETO runs bad. (sneezes and dies out at idle)

There not complete horizontal, if I manually push the linkage more down untill the metal stop the butterflies will be horizontal. At this moment there still blocking the flow a tiny bit, not sure if they are supposed to open till there laying 100% flat..

 

[99yam40]

Re: Yamaha 60 FETO runs bad. (sneezes and dies out at idle)

May not be designed to go all the way, I just do not know. Maybe some one with your motor can respond