Carburetor set up help - engine stumbling while planing
06-19-2019, 12:46 PM
#21
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I had a similar issue years ago. I did not see any post about setting the floats while the boat is in the water. The Vent tubes do no look like J tubes in the picture. The J are supposed to put gas down the carb throat if float sticks. My problem - the float settings was too high and extra fuel was coming out of the boosters. Reversion is not the problem at 3,000RPM and the 800 carb worked fine. You might be surprised if you check the float level on the water. My 2 cents 
06-19-2019, 01:32 PM
#22
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Thanks for the suggestions. What am I looking for float wise - fuel to be in the window when the boat is bow high?
Here are photos of the carb and the sheet that came with it - I've not changed anything inside the carb yet. Does the carbon or black discoloration help the diagnosis?
Ryan
Here are photos of the carb and the sheet that came with it - I've not changed anything inside the carb yet. Does the carbon or black discoloration help the diagnosis?
Ryan
I would check with prosystems where he wants the float levels installed in the boat. Most carbs with windows that I've set, were at the bottom 1/4 - not inch but the actual sight glass.
Short boats that can and do go sky high when planing don't have issues with the floats set this way.
I agree with MildThunder on how idle mixture screw should be set. If too lean, can cause backfire thru carb when planing. I set carb for best idle in neutral and then usually 1/8-1/4 turn richer(counter clockwise) will make engine idle better in gear and get rid of planing backfire if caused by too lean idle mixture screw setting. heated intakes don't have as much of this issue,but who runs those.
