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speed tips

Posted: Sun Jun 16, 2013 6:41 pm
by bostonwhaler
looking to make my boat faster if I can
Okay here goes. Im gonna give as much info as I can here, I don't know how to load a photo.
1989 skeeter sd 90 fs
1983 90 hp evinrude
13 inch 19 pitch prop
WOT is 5400 rpm 37 mph
This is with one person in the boat and I had my 2 trolling motor batteries out.
I took it out to see the speed without the batteries because they are getting charged up and I had a prop lent to me
my other prop was 12 3/4 with 17 Pitch, both are aluminum composite props,
the 17 p would red line the motor at WOT

Any tips to make this little stinger fly faster would be nice. Hole shot is very fast with both props.
boat is only rated for an 80
does anyone have any tips other than getting this old motor boredout and oversized pistons added

Re: speed tips

Posted: Sun Jun 16, 2013 7:45 pm
by moonshine
only thing I can think of is getting a stainless prop. the aluminum props flex a lot and you can only get so much out of them. 8)

Re: speed tips

Posted: Sun Jun 16, 2013 8:10 pm
by cgates
You can also get a Jack Plate that may help a bit

Re: speed tips

Posted: Sun Jun 16, 2013 8:14 pm
by bostonwhaler
Im okay with the 37 mph, but my buddy has a 96 nitro that is 2 feet longer than my boat and 15 less hp and he gets 51 mph, that kinda pee pee me off, that's all. lol If I can make her faster I would like to, also my hole shot is really fast, his is slow

Re: speed tips

Posted: Mon Jun 17, 2013 3:13 am
by Cyber
Your hole shot is faster than your buddy's because of the lower pitch prop. You can probably
get more top end with a higher pitch prop but will sacrifice that quick hole shot. :o You also
have to be very conscious of your RPM's as you go up in pitch, you don't wanna have it constantly
over revving or speed will no longer be any concern at all!!!! :shock: :shock: :wink: :lol: :lol: :lol: :lol:

P.S.: You really oughtta try out that S/S I 've got! :wink: 8)

Re: speed tips

Posted: Mon Jun 17, 2013 5:41 am
by CNs
Cyber wrote:Your hole shot is faster than your buddy's because of the lower pitch prop. You can probably
get more top end with a higher pitch prop but will sacrifice that quick hole shot. :o You also
have to be very conscious of your RPM's as you go up in pitch, you don't wanna have it constantly
over revving or speed will no longer be any concern at all!!!! :shock: :shock: :wink: :lol: :lol: :lol: :lol:

P.S.: You really oughtta try out that S/S I 've got! :wink: 8)
1) aluminum composite flexes -> alot! means less speed
2) going up in pitch means going from a 19 to a 21 inch pitch, As you move up, you lose about 200 rpm per inch. You will not over rev.
3) At wot you should be at 5800 RPM
4) What is the motor height pad to prop? most motors are mounted too low. If you have a jackplate lifting the motor 1/4 inch at a time. If you do not have a water pressure gauge this is a tricky thing to do.
5) If you do not have a jackplate - you should get at most, a 6 inch jack plate not more. This moves the motor into cleaner water changes the boat attitude, and should improve overall performance.
6) definitely try Cyber's prop - if it fits.

Re: speed tips

Posted: Mon Jun 17, 2013 8:41 am
by bostonwhaler
going to try the SS prop for sure. Hope makes a big difference.

Re: speed tips

Posted: Mon Jun 17, 2013 8:46 am
by bostonwhaler
If I go up in pitch it will bring my RPM down, its allready low at 5400 rpm, so I am thinking that if I do a lateral move to the SS prop I should be safe, unless switching to stainless affects your rpm as well

Re: speed tips

Posted: Mon Jun 17, 2013 9:45 am
by impactfishing
Sometimes going down a pitch will actually increase your speed, going to a 17 pitch would up your RPM to 5800ish and could push the boat faster than the higher pitch 19

Re: speed tips

Posted: Mon Jun 17, 2013 11:28 am
by bcjohnso99
Here is an interesting read...

http://bassclubdigest.org/columns/perfect_setup.htm

If you choose to go up in pitch, prop vents might let you maintain your current strong holeshot.

I have a 19" Merc prop with Power Vent. 19" is a bit high for a deep V multi-species boat so a prop with vents was chosen. I have not actually tried removing the plugs yet because the holeshot is adequate, but others have indicated that removing them will improve hole-shot but not hurt top speed.