Mercury ELPTO primer bulb question.

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Hvymtl

Petty Officer 2nd Class
Joined
Jun 6, 2011
Messages
147
I have a 2002 mercury 90 hp 2 stroke. Runs extremely rough at idle speed (no wake and there a lot of them in Florida) and is hard to start. The minute you throttle up come off idle it runs perfect to redline. Primer bulb will nut get hard when pre-squeezing to start, Rock hard when engine finally runs. Noticed fuel coming out of number 2 when in tilt position - other 2 have no leaks. What should I check first??
 
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Iceman66

Petty Officer 2nd Class
Joined
Jun 30, 2008
Messages
199
Most litely:Bad needles and/or seats in carbs, or dirt in same place,try a carb clean.

Could also be:
Bad primer bulb,Fuel-line leak,bad Fuel pump diaphgram. Check if it changes with a (another)portable tank.
 
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H

Hvymtl

Petty Officer 2nd Class
Joined
Jun 6, 2011
Messages
147
OK ..suspecting the primer bulb. I can squeeze it to prime and it never gets hard. I see fuel moving in the carb filter, but it will only get get half full using the bulb -- so there is no fuel being pushed in the carbs...hence the hard start? Once running the filter fills completely.

How can I check the bulb? If I squeeze it and block both ends the bulb stays compressed....but I think there is a checkvalve that keeps fuel from going back to the tank?
 
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Texasmark

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,559
What filter? OEM internal engine filters are white and you can't see thru them. Any leaking from the carb throat when tilted is the float valve not seating properly caused by a bad needle valve, or adjustment, or fuel logged float. Primer bulb should get hard when all carbs are full prior to starting. If not bad bulb or leaking carb as stated. This engine is cold natured on first start up. Fast idle up all the way, turn to start while pushing in on key to activate fuel enhancement solenoid (aka choke). Once it lights off limit rpm max to 2000 give or take. If it stutters push in on the key till it recovers. Rough idle with what you said about the rest of the operating range smells of idle screws not adjusted properly on each carb. Get a manual! I know I had one for 10 years. How did it run? Check my avatar.

Mark
 
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