Ive got a 1988 runabout that I bought in 1999. Its been running good. I like to slalom ski and have used a 17 pitch SS 3 blade and a 19 pitch Hi Five over the years. Ive been running the 5 for about 4 years with results like the 3 blade but with a tweaked PVS I think the engine is getting up to 3800 rpm during skier holeshot as opposed to getting stuck at 2500 rpm with the regular 17 pitch 3 blade. 3 second holeshot (no load), 0-30 in around 6-7 sec (no load) if memory servs, reaches over 4600 rpm wot but I dont let it go over 4600 since thats the spec.
I was rebuilding the carb and ran across a saying on the net that said one could rejet the main jets in this carb for more power and better acceleration. That would be great for my slalom skiing since deep water start is hard for me.
I have a 1988 year model boat and 3.0L mercruiser with a 1389-9562 model 2 bbl mercarb with 145 main jets operated at 530 ft above sea level in middle Georgia.
Since the engine runs well and there are no issues really with how it runs (aside from being limited on torque and hp for slalom skiing) would it be possible and beneficial to experiment with the jet sizes (larger) and possibly find more power to pull a skier out of the hole? I do see that newer models have different models of mercarb that look like they have larger bore sizes and also larger main jets. How does that affect the power area that I would be looking for? Why is my carb using the smaller bore size? Thanks for any advice or thoughts you might have.
i,d say your chipmunk is doing exceptionally well considering its doing the job of a horse you could bump the timing a we bit to perk it up a bit but listen for pinging of too much timing
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rejet mercarb for better performance
Posted - Jun 03 2012 : 09:17:11
