top carb on 90 merc

hl

Petty Officer 1st Class
Joined
May 2, 2010
Messages
239
Been messing with a 1983 90 hp for a while. Had it cranking and running good. Now when I pump the primer bulb it does not seems to get gas to the top carb. Before, during priming, it would show a little gas coming out the front of the carb and it would crank and sound great. Any ideas ?
 

hl

Petty Officer 1st Class
Joined
May 2, 2010
Messages
239
Re: top carb on 90 merc

Been messing with a 1983 90 hp for a while. Had it cranking and running good. Now when I pump the primer bulb it does not seems to get gas to the top carb. Before, during priming, it would show a little gas coming out the front of the carb and it would crank and sound great. Any ideas ?

could the float be set too high?
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,113
Re: top carb on 90 merc

Top Carb float set too low..... If you have backdrag carbs (likely), there is a screen under the brass tee tuel fitting on the top carb cover. These can get clogged.
 

hl

Petty Officer 1st Class
Joined
May 2, 2010
Messages
239
Re: top carb on 90 merc

Top Carb float set too low..... If you have backdrag carbs (likely), there is a screen under the brass tee tuel fitting on the top carb cover. These can get clogged.

Already check the screen and it is clear. Sprayed cleaner in all the passages. The lower carbs show a small amount of gas during priming. Could the primer bulb be bad?
 

ajgraz

Lieutenant Commander
Joined
Mar 1, 2010
Messages
1,858
Re: top carb on 90 merc

Stuck needle in top carb?
 
M

Maxz695

Guest
Re: top carb on 90 merc

A stuck float or needle obstruction would not allow gas to enter into the carburetor. Before you said it showed gas in the carb when priming meaning needle valve leaking or the float was stuck open, now no gas in the carb. My guess is the float or neeldle is stuck. ( gummed up)
 

hl

Petty Officer 1st Class
Joined
May 2, 2010
Messages
239
Re: top carb on 90 merc

A stuck float or needle obstruction would not allow gas to enter into the carburetor. Before you said it showed gas in the carb when priming meaning needle valve leaking or the float was stuck open, now no gas in the carb. My guess is the float or neeldle is stuck. ( gummed up)

Thanks for the replies. Maybe this weekend I will get time to tear back into the carb and recheck everything.
 

hl

Petty Officer 1st Class
Joined
May 2, 2010
Messages
239
Re: top carb on 90 merc

Went through the top carb and found nothing wrong. Put it all back together and the engine is a little difficult on the first start-up.After that it cranks normal. go figure.
 
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