90 hp fuel problems?

[tedmamou]

I have a 1990 90 hp-3cyl. Starts pretty easy and runs find after warming up a little but will bog down if trying to run at full speed. It I keep it backed down a little runs like a champ. Maybe fuel diaphram? But what is strange, after running it full speed for a while, the idle is rought--in fact, smell gas. If I let it sit for a while--cools down, then the idle is ok. Suggestions??
Thanks as always.

 

[verado7]

Re: 90 hp fuel problems?

an overheating stator could do this - but your symptoms could be fuel or ignition - it may just be that you think its cooling down and starts or excess fuel is evaporating and alowing it to restart - if you can pump the bulb and hold it firm with no loss of pressure i'd start at the igniton .

if your serious about doing your own work - you need a multimeter and dva adapter plus a manual - a few minutes of reading and you can test the ignition yourself -

otherwise it's simply an expensive guess - if it wasnt running at all there are a few tricks that can quickly point to one thing or the other - your case requires testing and its not that hard and fairly quick to do .

 

[tedmamou]

Re: 90 hp fuel problems?

I guess I should have said also that the pressure bulb never gets real hard.

 

[verado7]

Re: 90 hp fuel problems?

pump the bulb up and hold it firm - see if it goes flat -if yes -replace bulb and or fuelpump rebuild . if it goes flat still - carb overhaul ( leaking needles) .

 

[tedmamou]

Re: 90 hp fuel problems?

I pumped up the bulb until firm--held it and it gradually went down. Did notice that fuel came out of carburator chamber. Do you think it is the fuel pump or the inlet valves?

Thanks,

 

[verado7]

Re: 90 hp fuel problems?

yeppers - if you saw fuel coming out the carb throat or leaking between the bowl and body then get a gasket kit - inlet needles and remember to set the floats to spec. i'll see if i have the spec. in my book for ya unless you already have it - there should be zero leakdown . basically your looking at tthe cheaper of the kits -

 

[tedmamou]

Re: 90 hp fuel problems?

Ordered the carb. kits. Were you able to find the specs?

Thanks for all the help.

 

[verado7]

Re: 90 hp fuel problems?

you should have the square bowl type carb? if so 7/16in is the spec . just get it looking level - with the carb upsidedown .

 

[tedmamou]

Re: 90 hp fuel problems?

I really do appreciate the help. As soon as kit comes in, will tackle the job.

 

[kend301]

Re: 90 hp fuel problems?

If your carbs have bowl vents be sure they are clean , If they are clogged the bowl will pressurize and prevent the float from closing the needle.

 

[tedmamou]

Re: 90 hp fuel problems?

I will make sure and check this. Thanks for the heads up.