www.iFourWinns.com

I have a 24 ft vista with a 260hp 5.7L engine. The boat struggles to get on plane and it has to be floored with the trim tabs all the way down before it will level out. The top speed is 26mph. I am hoping someone who has the same boat can tell me what speed they get, what size prop they are using and any suggestions. Last year I had a three blade 15x17 prop which gave me a top speed of 32mph but at 5500rpm (way to high). This year I have a 4 blade 14.5 x 16, my max rpms are 4200. The engine has less than 200 hours and the carb was rebuilt last year. Anyone with any suggestions?
Thanks

Well, since you have no replies from "same model" owners, I'll just pitch in a thought or two.

First ..... assuming that the engine is running properly and making the power that it should be ... AND .... you are trimming the drive out to the most efficient cruise and WOT:

Your current WOT RPM is a bit low. I think with the four blade prop (which, in theory, is good for efficient cruise and pulling out of the hole), you now have too much pitch. I would try a 14" pitch on the four blade (as opposed to the current 16" pitch). This would raise your WOT RPM by 400 to 600 RPM and certainly help your getting out of the hole and up on plane.

With this said, I am suspicious of your curent engine power, when looking at your prior and current numbers. Have you put the old prop back on, for a test?

_________________
Gordon Arnold
New Hampshire

2003 268 Vista ..................................................................Prior: 97 245 Sundowner

Thanks for the reply. I switched the prop to a 15x19 and it made it worse, the boat would not even get up on plane. I am waiting for my old prop which is in the shop being repaired. Thanks for the advice, I will be looking to change the pitch down to see if it helps.

I have an 1989 245 VISTA with a 5.7L and was told by the factory that the prop should be 15.5 X 15. I have the same problem with plane and speed. I get about 26mph at 3500 - 4000rpm. I am not able to check my prop yet to see what mine is. I hope that this helps.

Bill
wmm383@yahoo.com

I put on the original prop and have the same problem. I found one problem with a bad gasket on the fuel separator which caused gas problems. I just did a major tune up, plugs,wires,dis cap, condenser and new filter. The boat got up to 27mph and ran fine for about eight minutes then slowed down to 10mph and would not get any faster. RPM's stayed the same. I changed the filter again and it worked fine for about five minutes then slowed down all buy itself. After plowing through the water for 10 minutes it fixed itself and went back up to 27MPH. No one seems to know why it is doing this.