no speed on 135 inboard help help

[gregthomasstar]

I have had my 2004 fisher 221 dlx for a couple years now. the specs from fisher say it should go 25 mph. I realize this is probably in a perfect world (propped right, trimmed right, less weight etc) However, with a 11p prop wot at 4800 rpm i could only get about 14 or 15 mph out of it. I switched to a 13 inch prop and it helped by only 1- 2 mph with wot still about 4500- 4600rpm. I also installed a good "whale tail" last year which again helped only by about 1-2 mph for a top speed of about 18mph wot 4500-4600 rpm. What else can i do to get more top end out of it? do i need to install 3rd toon or install water glide for a $1000.00? Also, i saw on newer pontoons they are now installing strakes which run the length of the pontoon on the inside and outside of the pontoon. However even if i could do this the trailer would have to be altered. Should i try a prop with 14, 15, or 16" pitch?? different kind of prop??? boat seems to be really pushing alot of water when cruising Help????

[dockholiday]

Welcome

Merc's specs call for 4400 to 4800 rpm. So it looks like you are there rpm wise. Not that familiar with the propping on I/O's, but with 135hp you should be able to get the 25 seems to me. Are you using speedo or gps for the speed recording? It's going to be a big jump from 18 to 25mph for a prop change. As you have found out a few hundred rpm an a few mph are the norm. Could try the enertia 14p, but they are pretty costly, but would be worth it if you had someone that would let you try diff props till you found the right one.
doc

[TX0303]

According to iBoats.com, that boat has a dry weight of 2880 lbs, which is heavy for a 22 footer but I guess includes the weight of the motor. When testing, how much extra weight are you carrying? Are you sure there is no water in the logs?

[WaltF]

Our 22 foot with a 135 i/o goes about 25 mph with less then 4 on board at WOT (4800).
The prop is an 11 pitch x 16 dia aluminum 3 blade.
Trimming so its a bit nose high seems to help as far as the toon having to 'push' its way through the water....