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30 mph from a '99 115 merc.
Posted: Mon Feb 16, 2015 11:23 am
by gobeernet
What does it take to get 30 mph from a 115 2 stroke on a 22' pontoon. Lifting strakes? Third Toon? Both? Not gonna happen?
I took mine out last weekend and got 22mph GPS w/ a bent 15 pitch stainless prop. Engine reaches max RPM. Prop is at the prop shop right now. The toon is 22' with 22" or 23" pontoons. I ran across a 23' 25" center log with transom and lifting strakes. Its not cheap or close, but the price and the distance would be worth it to me if it got me to the 30mph mark in addition to handling rough water better. Also the diameter, length and transom seem to make it the "easiest" arrangement for a triton retrofit on my boat.
Re: 30 mph from a '99 115 merc.
Posted: Mon Feb 16, 2015 1:07 pm
by rdeterman
Seems like a lot of work to get a few more mph out of your current boat. I would say if you are dead set on keeping your boat and not putting your money towards something else with a larger motor and/or third toon it might work. My last boat was a 24ft 2 toon with a Yamaha F115 and it would run 27mph gps, but if i were you id get that prop fixed first then go from there, you might not be as far away from 30 as you think.
Re: 30 mph from a '99 115 merc.
Posted: Mon Feb 16, 2015 3:22 pm
by Ddancers
24' (actual 25' 8") 2 tubes 27" - Lifting strakes - Yamaha 115 4 stroke - 2 people 18 gals 27.3 mph GPS . I would think 30 mph on 22' is in the ball park .
Re: 30 mph from a '99 115 merc.
Posted: Mon Feb 16, 2015 7:06 pm
by gobeernet
rdeterman wrote:Seems like a lot of work to get a few more mph out of your current boat. I would say if you are dead set on keeping your boat and not putting your money towards something else with a larger motor and/or third toon it might work. My last boat was a 24ft 2 toon with a Yamaha F115 and it would run 27mph gps, but if i were you id get that prop fixed first then go from there, you might not be as far away from 30 as you think.
I agree about getting the prop fixed and go from there. What diameter toons were on your 24'? Also did it have lifting strakes?
I'm not against selling and purchasing a nicer/faster boat, but it doesn't seem cost effective. I figure $1200-$1500 and a weekend to retrofit a third toon to this boat. Price to upgrade to a tritoon with same or bigger motor is probably $4-$5k+
Re: 30 mph from a '99 115 merc.
Posted: Mon Feb 16, 2015 7:08 pm
by gobeernet
Ddancers wrote:24' (actual 25' 8") 2 tubes 27" - Lifting strakes - Yamaha 115 4 stroke - 2 people 18 gals 27.3 mph GPS . I would think 30 mph on 22' is in the ball park .
I'm guessing 24-25mph from mine when prop is fixed.
27" diameter w/ lifting strakes sounds like the extra few mph on your pontoon over mine.
Re: 30 mph from a '99 115 merc.
Posted: Mon Feb 16, 2015 7:11 pm
by RcgTexas
With a center log with lifting strakes it is possible! MY 23 footer does 32+ but it isn't your normal tri toon.
Re: 30 mph from a '99 115 merc.
Posted: Mon Feb 16, 2015 8:22 pm
by gobeernet
RcgTexas wrote:With a center log with lifting strakes it is possible! MY 23 footer does 32+ but it isn't your normal tri toon.
So tell me more - Got a write up of the conversion?
Re: 30 mph from a '99 115 merc.
Posted: Tue Feb 17, 2015 8:11 am
by RcgTexas
Sorry No write up. But I do have pictures they are posted on here. I may can answer questions if I remember the answers.

Be glad to help if I can.
Here is the link to my rebuild:
viewtopic.php?f=16&t=19016
Re: 30 mph from a '99 115 merc.
Posted: Tue Feb 17, 2015 9:25 am
by rdeterman
gobeernet wrote:rdeterman wrote:Seems like a lot of work to get a few more mph out of your current boat. I would say if you are dead set on keeping your boat and not putting your money towards something else with a larger motor and/or third toon it might work. My last boat was a 24ft 2 toon with a Yamaha F115 and it would run 27mph gps, but if i were you id get that prop fixed first then go from there, you might not be as far away from 30 as you think.
I agree about getting the prop fixed and go from there. What diameter toons were on your 24'? Also did it have lifting strakes?
I'm not against selling and purchasing a nicer/faster boat, but it doesn't seem cost effective. I figure $1200-$1500 and a weekend to retrofit a third toon to this boat. Price to upgrade to a tritoon with same or bigger motor is probably $4-$5k+
My old boat had 25" toons and no lifting strakes.
Re: 30 mph from a '99 115 merc.
Posted: Tue Feb 17, 2015 10:27 am
by Waterlogged
22' 26" toons with strakes, 115 merc 4s, 15p prop, I've seen 31 mph gps with 2 onboard abt 40 gal fuel.
Glenn
Re: 30 mph from a '99 115 merc.
Posted: Tue Feb 17, 2015 7:16 pm
by gobeernet
RcgTexas wrote:Sorry No write up. But I do have pictures they are posted on here. I may can answer questions if I remember the answers.

Be glad to help if I can.
Here is the link to my rebuild:
viewtopic.php?f=16&t=19016
Thank ya. Its a good read. I wish I knew someone around here that would build a toon'hull similiar to that. I think you should make the (Knot Normal) in your signature a link to your build page.
Re: 30 mph from a '99 115 merc.
Posted: Wed Feb 18, 2015 5:11 pm
by RcgTexas
Ha ! if only I knew how.

Re: 30 mph from a '99 115 merc.
Posted: Fri Feb 20, 2015 6:51 pm
by gobeernet
RcgTexas wrote:Ha ! if only I knew how.

Click on "user control panel" in top right of website.
Left side has Profile listed under Options.
Select "edit signature" and paste the below text.
You'll have to add a "[" before the first world "url" and a "]" after the last word "url".
Change this line to say what you want. url=
viewtopic.php?f=16&t=19016][Knot Normal][/url
Re: 30 mph from a '99 115 merc.
Posted: Fri Feb 20, 2015 9:09 pm
by RcgTexas
Thanks for the help! That's works great!
Re: 30 mph from a '99 115 merc.
Posted: Wed Feb 25, 2015 8:25 am
by STEVEBRENDA
There is no mention of how much furniture and other weight you have on your boat. When our boat was new, we could get 32-33 mph with our 125 HP. Now that it is a little older we only get 27 MPH. But also note we have a lot of furniture on our boat.
When you add the center log you are also adding more weight so your gains might not be as great as you think they are. With that said, I would still add the third log. The ride is so much better and safer. You may not get all of your money back when selling, but I think you will get most of it back.
You never did mention how big you 15 pitch prop is.