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1991 90HP Merc oil injected, tough to start hesitates from idle to full throttle

U

utfd701

New member
Hi all, new here and new to boat ownership. I have a 1991 Blue Fin with a 1991 Merc 90hp oil injected motor.
My problem, it can be tough to start and requires some throttle to get it going. Once is it warmed up seems to idle just fine. Additionally if I am idling or running very slow speeds and decide to jump on it, it hesitates and sometimes stalls (will start right back up). I have to ease into the throttle and once it is past the hesitation i can get on it. It is currently winterized but I plan on some 'remodeling' soon and would like to get after the motor soon. Thanks in advance for any help.
 
First thing is to check your compression, it's easy to do. if that's good try merc power tune, follow directions on can.

If that doesn't do it then maybe carbs would be a good bet. Could be timing perhaps but carbs would be my guess.

if compression is good you likely have a good motor. Put a new water pump in it stat. Make sure you have fresh gas and use good oil! Check spark plugs too. Do some research.
 
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