Do you think more pitch will help?

Hey guys,

I'm running an 87 Starcraft FM160 with an 87 Suzuki DT65. I really like the power of this motor, it gets the boat up on plane right away and pushes it the same speed no matter the body count (I've run with 4 onboard and one in tow and it just goes). However, it seems to top out max speed at 3/4 throttle. When I push it to 100% throttle you can hear the engine rev up a bit more yet I gain absolutely no speed. (Note: This is NOT the famous rev-limiter problem, the engine is revving all the way). The prop it came with (when I got it) is a Michigan 032042, 13x11 1/8". The boat isn't heavy, and this happens even if there are only two of us with only 6gal on the boat on a flat day. My best guess is that I am just under propped? I do not have a tach so I cannot say for sure what RPMs I am running, I just know by ear that the engine easily rev higher without increasing speed. Thoughts? If you had this motor on this boat what prop would you automatically select? Mostly used for fishing inland or near shore (got a kicker for trolling) but we like to get out on Lake Erie to play in the summer too.

Thanks!

Nick

Re: Do you think more pitch will help?

32bit.flannel said:

Hey guys,
I do not have a tach so I cannot say for sure what RPMs I am running, I just know by ear that the engine easily rev higher without increasing speed.

Nick

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Hi Nick,

You cannot accurately determine what prop you need without knowing your WOT RPM. Just about ALL engine manufacturers (outboard, I/O, inboard, etc) suggest a prop that will give you an RPM in the maximum recommended "range" with the throttle at WOT and the boat loaded (AND NOT over loaded) where you will operate "most" of the time.

Assuming the engine is running correctly, and the boat is typically loaded............without knowing your WOT RPM, it's pretty much impossible to tell.....

Re: Do you think more pitch will help?

Nick: It is also typical with 2 strokes that when you go from 3/4 throttle to full throttle the engine will make a lot more noise, use a lot more fuel, and only go a couple of miles faster--if that.

Delivering the same speed with all loads does sound a bit like you are underpropped BUT--as stated above, without a tachometer and RPM readings you simply are shooting in the dark. "You can't get to where you are going unless you know where you are starting"