135 hp on 14.5 ft arrow glass cougar prop help???

I have a 135 evinrude that I had on a 15.5 foot ranger bass boat and it ran great would run 5100 trimmed up. I took it off the ranger and put it on the cougar and now it will go go to 5900 with out even trimming it up. I can only run about 3/4 throttle to keep it at 5000. It has a 12 3/4 x21 stainless omc prop. The motor is mounted as low as it can be where the cavitation plate is even with the bottom of the hull. It will make it to about 30 mph on the gps and that is about it. My question is do I just need a bigger prop going from the bass hull to a trihull?

I was thinking I need to move the motor up but I figured it would make the rpms higher. Second question if the motor is to low would it have to much drag making the prop slip more and the rpms go higher.

It also has a new hub in the prop any help would be great.

Re: 135 hp on 14.5 ft arrow glass cougar prop help???

Your Engine can safely run at 5500 RPM without issue. The operating range is 4500-5500 however hitting 6000 RPM won't hurt it any. You are under propped you should be running a 23" stainless with that combination. The engine could move up a little but it is not that critical as long as the ventilation plate is even with the bottom of the hull.

I ran a 17" deep vee with a 78 140 with 23 pitch prop she would turn 6000 at WOT trimmed out.

Re: 135 hp on 14.5 ft arrow glass cougar prop help???

So 5500-6000 is ok i swear the plate on the motor says 4000-5000 as the operating range. Iboats says 5000 in the motor info and the prop sites say 5000-6000. What is the definative answer.

Talked to the prop shop they have a 13 1/2 x 22 raker they want me to try what do you guys think.

Thanks for the help

Re: 135 hp on 14.5 ft arrow glass cougar prop help???

I would put the raker on and see what she turns. The brochure for the 1975 135 says 4500-5500 with a 135 horse being produced at 5000 RPM. OMC always went 500 above and below the peak horsepower RPM.

Re: 135 hp on 14.5 ft arrow glass cougar prop help???

That works I will have to go down and get the raker prop when I get home from racing up here in NJ and give it a try.

Re: 135 hp on 14.5 ft arrow glass cougar prop help???

hey I might have found my problem. Which might mean there was no problem in the first place. The tach I got from our local boat yard was used they said it was on the same style motor and was set on the right pulses I got to thinking about it and the motor did seam to get rpm pretty fast on the tach. Looked at the tach when I got home and sure enough the thing was set on 2 pulse and the destructions on the teleflex website say 6 pulse for OMCs. I am guessing my data was a little scewed so i will have to take to boat out and try it again before I waste money on a diffrent prop.

Thanks for the help

Re: 135 hp on 14.5 ft arrow glass cougar prop help???

Finally got a chance to take the boat out again last week. With the tach set right the reading look a little better. Pretty much runs the same as it did on the bass boat. Now to make is faster. Trimmed all the way up on flat water the RPMs top off about 4800-5000. I am looking at a 13x18 Raker prop for it. I dont know if it will raise the rpms up enough though. What do you guys think??