stalling

[wolfmann]

Got a 1985 90hp yamaha runs well but has a problem with the low idel. It starts up then has a couple of hick up and stalls. It will restart with no problem.
Have replaced fuel pump checked ignition had a marine service mechanic check it over no one has found a problem. I have full power and the motor runs fine once you get past the low RPM range. Motor has no other symptons.
Any suggestions??
Thanks
Wolfmann

 

[blouderback]

Re: stalling

Sounds like it needs a carb cleanout or maybe even a rebuild. It is 20 year old carb.

 

[wolfmann]

Re: stalling

Has been done

 

[rodbolt]

Re: stalling

then do it again
the hiccuping means its running lean.
that hiccup is actually the fuel mix burning in the crankcase instead of the cylinder.
means the explosion is taking palce under the piston instead of on top.
with no other symptoms most likly you have one or more carbs with a restricted idle fuel pasage or a missing pilot air jet.
its either passing to much air at idle or not enough fuel. take your pick.

 

[wolfmann]

Re: stalling

Thanks for the info I have not heard about this before firing in the crankcase but it makes sense and as soon as the weather warms up in Canada I will do another rebuild of the carbs
I might have missed something
Wolfmann

 

[boatmanjf]

Re: stalling

new to this room but I agree Had a 93 merc. do the same thing, Bad carbs. rebuilt and my idle and top rpm cleaned right up.

 

[DavnJon]

Yamaha 90 Stalls at full throttle

Yamaha 90 Stalls at full throttle

Hi Folks,

Any help is appreciated. Got a rebuilt 90 HP Yamaha which runs better than good, but when at full throttle for more than a couple of minutes, she just loses it, starts to lose power, then dies altogether. Starts right back up - every time, always able to get it back to full throttle.

I'm convinced it's a fuel problem of sorts. My buddy suspects water in the tank, but:

Took it out today and ran it off the spare 6 gallon tank, which was empty and dry when I filled it, and it still happened again. (Only once though)

So if it's a fuel problem, it's internal to the motor. Maybe the fuel filer?
Help! The flounder are calling!!!!!!!!!

 

[cousinabe]

Re: stalling

fuel pumps