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carb problem 1991 90 hp

V

vane

Regular Contributor
just replaced my enriching devise n spark plugs on my 1991 mercury 90 hp 3 cylinder thinking that it was bad,also pulled the drain screws in the bottom of each carb hoping it might help..But obviously it was not the problem,still very hard to start{flooding out} and only running if idled way up.The only time it runs good is if I disconnect the gas line,runs like nothings wrong,it will even idle till it runs out of gas,but as soon as I put gas line back on it starts spiting n sputtering.Is it possible 1 of my floats are stuck.not sure what to do from here.any suggestions would be great.
 
Re: carb problem

Yes, definately sounds like it's time to rebuild the carbs - all 3 of them.

Carb kits are about 35 bucks each and add in 35 bucks for a Seloc's manual which will give you a step by step (plus do's/don'ts) for rebuilding them - so about 140 bucks or so and it really isn't as difficult a job as it might sound.

If that sounds like alot, the "going rate" for carb rebuilds at a shop, including parts is $200 for the first carb and $150 for each one after that - so $500 in this case - that should be a good DIY incentive.

Ultimately, if you decide not to bother, just keep in mind that probably 95% of cylinder/piston failures requiring rebuild or replacement of the powerhead can be traced back to an uncorrected carb malfunction. Doing nothing can be an expensive decision in the long run...
 
Re: carb problem

galamb said:
Yes, definately sounds like it's time to rebuild the carbs - all 3 of them.

Carb kits are about 35 bucks each and add in 35 bucks for a Seloc's manual which will give you a step by step (plus do's/don'ts) for rebuilding them - so about 140 bucks or so and it really isn't as difficult a job as it might sound.

If that sounds like alot, the "going rate" for carb rebuilds at a shop, including parts is $200 for the first carb and $150 for each one after that - so $500 in this case - that should be a good DIY incentive.

Ultimately, if you decide not to bother, just keep in mind that probably 95% of cylinder/piston failures requiring rebuild or replacement of the powerhead can be traced back to an uncorrected carb malfunction. Doing nothing can be an expensive decision in the long run...
Click to expand...
Thank you again Galamb for the info,I bought a selco manual off this site a month ago>I'm not to worried about rebuilding the carbs,just adjusting the air fuel mixture,is what I am worried about,I rebuilt my carbs on my 50 yamaha and it was easy till I tried to adjust the air fuel mixture,well to make it short, the shop got to do that for me. ahh maybe I'll get it this time.If not sure they will be happy to see me again.Thanks again..
 
Re: carb problem

Just follow the recommendation in the manual - seat them lightly then back them out the 1 1/2 turns (or whatever).

It can be a little trickier on a multi-carb set-up to get them all (tuned) but just have to work on them "slowly".

When you adjust, all from the same starting point (say 1 1/2 turns out), tweak them ALL 1/8 of a turn and then give it 20 or 30 seconds to respond and then decide if that adjustment made things smoother or rougher and just keep going like that until you are happy.

If you don't adjust them all the same that's when things can get both confusing or the motor will run "crappy" (that's a technical term by the way) :)
 
Re: carb problem

galamb said:
Just follow the recommendation in the manual - seat them lightly then back them out the 1 1/2 turns (or whatever).

It can be a little trickier on a multi-carb set-up to get them all (tuned) but just have to work on them "slowly".

When you adjust, all from the same starting point (say 1 1/2 turns out), tweak them ALL 1/8 of a turn and then give it 20 or 30 seconds to respond and then decide if that adjustment made things smoother or rougher and just keep going like that until you are happy.

If you don't adjust them all the same that's when things can get both confusing or the motor will run "crappy" (that's a technical term by the way) :)
Click to expand...
Thanks again Galamb,Going to give it a try.Your knowledge has been very helpful in the past ,and now in the present,Thank you again God bless U
 
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