Re: Throttle hesitation adjustment?
what's happening is called a "lean-out condition". Without getting too technical the carb is going from one operating state to another and there's a lack of fuel.<br /><br />the cause of this is if it's a "mercarb" is Mercruiser and their **** poor design for a carburetor. It has an inadequate transition circuit.<br /><br />The solution(s) are to adjust the float so fuel level is higher in the carb; this causes the main metering ciruit to come online quicker and you won't get the hesitation. This is the majority of the problem in the case of the mercarb. Don't go by a measurement specification (10mm or 14mm) in the service manual. Trial and error adjusting the float to raise fuel level will fix the problem. You won't hurt anything, you'll know you raised it too much when fuel drips out the booster at idle in droplets and the motor will idle terribly if at all, then you have to adjust float to lower fuel level.<br />In addition, you can also rejet the carb- replace the main metering jets (there are 2) with larger ones. This will also help with acceleration power. My model, a 2002, has stock jets of 1.55mm; I run 1.70mm with float about as high as I can get it. Find your engine model number, and carb model or casting number, and punch it in to mercurypartsexpress.com. Jets are cheap, but the bowl gasket only comes in a kit which is $30.<br /><br />The accelerator pump is not the solution. The purpose of the accelerator pump is to manually shoot a volume of fuel when the throttle is open rapidly! When this happens there is a sudden loss of vacuum and the carb doesn't know what to do. The acc. pump shoots the right amount of extra fuel when the throttle is punched so there is no bog. If you are trying to cure a lean out condition by having the accelerator pump shoot the fuel, it can be done but it's a roundabout way of fixing the problem and forces you to always jab the throttle. If you accelerate easy, the acc. pump doesn't shoot and you still have the hesitation, due to improper fuel level in bowl and/or an inadequate transition circut in the carb.
