Pontoon Boat & Deck Boat Forum

I own a 2009 24' starcraft sunchaser with a 90hp twin toons no underskinning. Last year had a new lower end unit put on because dealer did not service engine properly over the winter and it cracked. He replaced lower end at no cost to me. Before the replacement I was getting about 23mph full out at 6200rpm. After replacement last year it was down to 16mph at 6200mph. Called dealer he said it would come up after a year. Well this year its down to 13mph at 6200rpm. My question is: Is it possible he put a leg that is too short on? Maybe a wrong gear ratio? I am going to speak with him next week and was looking for some thoughts /input from you guys!!!
Thanks!
Smitty.

All indications point to something the dealer did BUT while you are waiting on him, I would rule out two things on your own:

1 - Added weight. Check to see if you have water in your toons.

2 - Growth on toons. Dirty toons will kill speed. Prior to having my lift, I would see that kind of speed loss (at same RPM) due to algae growth.

BobL wrote:All indications point to something the dealer did BUT while you are waiting on him, I would rule out two things on your own:

1 - Added weight. Check to see if you have water in your toons.

2 - Growth on toons. Dirty toons will kill speed. Prior to having my lift, I would see that kind of speed loss (at same RPM) due to algae growth.

Thanks BobL! I have not cleaned the algae off. That would make sense given the gradual loss.

Last year, my boat was new. I kept it in the slip.

New, I'd get 24mph per the gps with the bimini up and 6-8 people on board.

By end of year, it was at 19.6-20 topped out.

When we pulled it for the winter, everything got pressure washed off, the toons were "Clean". (Relative as they weren't "Shiny").

Put it back in this spring, top up, 24 mph.

Evidently, Algae and zebra mussels do slow em down a bit.

I wonder if the dealer replaced the lower unit with a used one? Or, a SEI unit? Or one with the wrong gear ratio off a different horsepower motor? Gear case are awfully expensive new. If he put a used lower unit on there, it could also have a problem.

It's all a lesson to be learned to have your lower unit pressure and vacuum tested from time to time to make sure the seals are good. Bad seals = water in lower unit= frozen lower units.

Start by checking for water and cleaning the toons. If speed's abnormally low, I'd have the lower unit checked out by a qualified marine mechanic.