mercarb overhaul advice

inchman

Cadet
Joined
Apr 18, 2007
Messages
24
hi ive a baylner trophy with a 3.0 l mercruiser engine (1987) ive tracked down a miss at 3000 rpm and 3500 rpm to my carb. i printed of the mercruiser manual and i'm setting the float height. the manual isnt too clear and i would like to know where exactly to measure to on the float. its a black plastic float with a seam running horizontally along it.

cheers Gary
 

fixb52s

Chief Petty Officer
Joined
May 14, 2004
Messages
463
Re: mercarb overhaul advice

Does your float have the 2 "dots" like in the photo? You have to measure it from the one shown to the carb base, with the gasket in place. Don't forget to use the same reference when checking for both float cutout AND float hang.​

If your kit came with a small ruler, MAKE sure you read it correctly. On mine, the measurements were in different increments than the value. The float cutout was 9/16 (with the spring loaded needle) and hang is 1 1/4.​

Also make sure you check and see if your carb has the check balls in both the accelerator pump chamber (under a clip and screen) and in the body itself. Depending on what carb you have, you might have both check balls or just one. Also ensure that passage that goes from the accelerator pump to the metering area is clear. Every carb I rebuilt has this passage totally blocked, and it takes some cleaner and compressed air to clear it.​
 

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inchman

Cadet
Joined
Apr 18, 2007
Messages
24
Re: mercarb overhaul advice

thats my problem, there are no dots on my float just a a step at the end. Ill check the passageway . thankyou very much for the advice.

cheers Gary
 
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