Low Idle on Sporty

[waterskiercu]

I have a '01 Sporty with the Vortec carb. Had the carb rebuilt last year by Malibu dealer -- in the early going, everything was fine; idled around 700ish. End of the season was having some issues -- may have been vapor lock due to extreme heat -- and boat stalled out a few times and idle seemed to bounce around a bit. No issues when boat is running/we skiing. This past spring, did my own oil change, fuel filter replacement, ATF, etc. Boat starts right up but the idle remains really low -- right at 500. I'm not mechanically inclined so hesitant to start messing with the idle screws. Guy that works on my car is an avid boat owner and offered to take a look. Not being cheap but the wait line and service cost of Malibu is absolutely ridiculous. Was hoping it just needs a few adjustments. Thoughts on it being the carb or potentially something else? Thanks. 

[Rednucleus]

If your buddy is comfortable with a carb basic adjustments are easy.  Should be an idle speed screw on the linkage you can easily bump up rpms a bit.

[Woodski]

I believe if an Indmar your carb will be like this one:  idle speed adjustment is done via screw 175/176 in diagram.  Google Holley carb and lots of info at your fingertips.

Edited May 3 by Woodski

[justgary]

I would guess that an idle problem is related to either a vacuum or fuel leak.  You could try spraying some starter fluid around the base and seams of the carb with the engine idling to see if you get a bump in RPM.  Fuel leaks may be harder to deduce, but double-checking the float level is a great place to start.