motor height

[evin268fs]

I having been reading quite a bit about setups, and to improve speed and increase rpm's everyone is always suggesting raising the motor. Especially if intrested in trying 4 blade props. Since I do quite a bit of skiing, I was wondering, how does raising the motor effect holeshot? If there is a negative effect, how high before the effect becomes noticable? Also, how do jackplates effect holeshot, bette, worse, no change.

 

[WillyBWright]

Re: motor height

Setting up for speed is the exact opposite of setting up for towing. You want the motor planted as firmly in the water as possible. Surface-piercing props are useless for skiing. So are ventilation holes in the prop. If you want holeshot, get a low pitch prop and watch the RPMs on the tach so you don't overrev. Ski club boats are WAY underpropped to allow high RPMs at skiing speeds. Otherwise you're running half-throttle which means half-power.

 

[evin268fs]

Re: motor height

So raising the motor will not be something I will probably look into, thanks

 

[Crownie2]

Re: motor height

One thing - some boats have more power than they really need for skiing, so in that case raising it may not hurt your towing ability noticably, especially if you have plenty of trim-in.

Been there, done that.

Bob

 

[walleyehed]

Re: motor height

I agree with Cownie...
Although going to a lower pitch will help...a vented prop may allow you to keep from going quite so low....it can make about 2" difference equivilant in pitch for hole shot. A std 17 with vents will have close to the same hole-shot as a non-vented 15. Which ever prop you would choose, it should put you slightly above max RPM at WOT, normal load.

 

[evin268fs]

Re: motor height

I was thinking about getting one of those 17"-4 blade solas amitas (on sale now on this site), how do you think it would do?

 

[walleyehed]

Re: motor height

That would be like going to an 18P 3-blade...might be better hole-shot, but what prop are you running now?
That would help quite a bit in determining what we got here....boat type would help too...

 

[evin268fs]

Re: motor height

I will have to get back to you, I havn't actually picked the boat up yet, just put the deposit down, found researched the type of moter, (looper) got compression check, and made sure everything was in good working order, picking up from an evinrude dealer who did all of the maintenance since it was new. Used to ski behind a 1987 18" Tidecraft with an 18" Raker (old style), and 1987 115 crossflow. About 15 lbs ago I could not longer slalom with that setup, I guess 185 lbs is the threshold, (200 now) possible wet foam in that boat as well, I could drag forever but the boat would not plane and engine wind up, Can get up easily behind my uncles, overpowered 15 foot trihull (with ski pylon) and a 1970's 125 Johnson, 18 pitch(no cupping) allumium, no problem, I am scheduled to pick it up after the first of the year, just anxious, and overanalying things right now. This site is great and allows people like me to learn. For all I know, the right prop could be on the boat now, but after reading this site, I want to make sure it is set up as per the advice of the site to have the engine last a long time.