I'm asking this question for a friend and you guys are the experts.
The boat will run about 32 mph GPS, and turn about 4200 rpm. It has a 21p prop. It also porpoises very bad and you just can't find a sweet spot in the trim. There is no jack plate on the boat.
Does anyone have one of these boats? He's interested in what speed you get and prop you are using. Any help or advice would be appreciated.
Sounds like its over propped to me
1999 Stratos 273 DC
1999 Johnson 115
2021 Ram Limited
That's what I was thinking. We ran a compression check yesterday, it's a little weak, between 95-100 on all cylinders. Going to try a 19p prop today.
So the deal with compression tests are is that gauges read differently so you really don't know if it's weak or not. The important thing is that the numbers are all withing 10% of each other which they are.Originally Posted by Kenfuel
My guess is it's over propped, not getting full throttle or something like the boats water logged, but I don't think the cylinders are wore out.
Anyway, good luck
2000 Javelin Renegade 20 DC.
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Thanks for the reply. Tried the 19p and picked up 300 rpm but no more speed. I checked and all the carbs are fully opening. Motor is smooth and sounds good.
I've used the same compression gauge on my 175 and it checked 120-125 on all cylinders. Maybe it is water logged, its definately not loaded heavy, 3 batts and a half tank fuel, with very little equipment. Shouldn't this boat run at least 40-45 mph?
what kind of prop is it?aluminum or stainless performance prop or
just a regular ol prop?
Both pitches were factory mercury props, and stainless. I dont know the part numbers.
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