Rochester 2G hesitation?

I have an older 87 bayliner, with a 3.0 and OMC outdrive. it runs great but it has a hesitation just off idle. It happens when you put it in gear its fine but then start to throttle up, the very initial throttle application almost kills it if you nurse it through that it is fine. Doesnt seem to do it once under way and you try to accelerate.

I was thinking it might be accelerator pump, but I would think this woudl occur at all speeds, unless the off idle transition circuit in the carb cant keep up like the main metering can once you are under way. I have thought about rebuilding the carb to see if it takes care of it but thought i would look at other possibilities as well.

I did notice that with the throttle linkage removed, you can work the thottle arm by hand and there is some play in it where you can move and see the throttle blades start to open just a little before the pump kicks in. My original thought was that this was causing the hesitation, but the slack, sems to be inside the carb with the accelerator plunger itself not with the outside linkage. Would a new carb kit take care of this slack in the system?

FYI
Its a Rochester 2G carb.. Are there any adapters available to put a Holley 2barrel on in place of it?

Re: Rochester 2G hesitation?

My Merc 3.0l with a Mercarb was doing the same thing. I rebuilt the carb, and it was better but still a hesitation. I did more research and found the accelerator pump rod actually should be "carefully" bent to ensure the proper engagement time for the pum. Mine was 1-5/32" from the top of the air horn ring to the top of the rod. Works like a charm now. I guess the pump wasn't kicking in soon enough. Good luck.

Re: Rochester 2G hesitation?

Are you talking about the rod that runs from the throttle shaft up to the pump? Or a rod inside the carb?

I thought the same thing about the rod on the outside but adjusting the length of it changed nothing, it still has a hesitation in the pump shot.

Re: Rochester 2G hesitation?

MBAKER,

Did you fix the problem ? The same thing is happening to my 1987 bayliner capri. Let me know if you fix it. Thanks