Malta Fishing Forum
International Game Fish Association
News:
 
*
Latest Gallery Pictures






Pages: [1]
  Print  
Author Topic: Kaptan boat with 9.9 yamaha vs 15 Evenrude  (Read 10762 times)
0 Members and 1 Guest are viewing this topic.
bigboy
Guest
« on: July 31, 2008, 13:14:49 CET »

Guys i have a really big dillema and also am a bit worried. We just got a 13ft Kaptan boat powered by a 9.9 yamaha. On my Albatross i have an Evenrude 15hp and we decided to try it out on the kaptan. The results we got were really worrying and shocking. With the 9.9 it was giving a clear 16.5 knots with 2 persons and with the 15 it gave us 14.2 knots with the same load.

We were waiting that with the 15 it would do at least 20 knots because it is much more pwerful than the yamaha. Could it be i have some sort of trouble in my engine or what  Huh Btw they are both long shaft.

Help from you guys would be kindly appreciated.
Logged
benri
VIP Member
Active User
*****
Offline Offline

Posts: 940



« Reply #1 on: July 31, 2008, 13:40:05 CET »

Is the propellor pitch the same? 99.9% the only reason is that you need a different propellor on the bigger motor for the Kaptan.
Logged

I'd rather be fishing.....
shanook
Senior Moderator Team
Active User
*****
Offline Offline

Posts: 2993



« Reply #2 on: July 31, 2008, 14:55:44 CET »

i had a kaptan 13ft and i used to do 18knots with a 9.9 Force. u should do better with a 15hp. kaptan boats plane a lot better than other boats
Logged
visa
VIP Member
Active User
*****
Offline Offline

Posts: 221


my biggest catch


« Reply #3 on: July 31, 2008, 16:07:48 CET »

big boy first check if the 9.9hp is opened to 15hp this is oftern done so that the owner is not made to regester the 9.9hp i had one and used to push my 19ft boat at around 7/8 knots. and most probely htats the reason. Have fun and dont worry about your 15hp it could be that it just needs a better propeller as benri suggested.
Logged

RASCALA 24ft. with DF225 hp SUZUKI v6 4 stroke
busumark
Premium Member
Active User
***
Offline Offline

Posts: 1114



« Reply #4 on: July 31, 2008, 16:49:53 CET »

most probably the 9.9 is changed to 15hp but basically they are the same engine there isnt a lot of difenrence between them
Logged
bigboy
Guest
« Reply #5 on: July 31, 2008, 17:55:25 CET »

no it is not changed. It is a 9.9.
Logged
skip
Administrator
Active User
******
Offline Offline

Posts: 3952



WWW
« Reply #6 on: August 01, 2008, 04:59:55 CET »

On the basis that a 15hp is probably factory propped to push a heavier boat I would say off hand you don't have enough pitch on the prop. Have a look at the stamping on the prop of both and let us know. You're looking for something like 9.3 x 8 for example.

If you connected a rev counter temp to the 15 you'd probably find you are at the top end of its WOT, so you're not getting that extra power without putting a more aggresive pitch.
Logged
bigboy
Guest
« Reply #7 on: August 01, 2008, 07:36:26 CET »

Skip what does WOT mean please? i will try get the size and pitch numbers of the propellers tonight. Thanks very much for your help Smiley it is much appreciated
Logged
skip
Administrator
Active User
******
Offline Offline

Posts: 3952



WWW
« Reply #8 on: August 01, 2008, 07:49:51 CET »

WOT is Wide Open Throttle and it's a range specified by the manufacturer to indicate the ideal maximum engine operating range, probably something in the region of 5200-5800rpm for your engine. The WOT is used as a guide to select the correct pitch allowing the engine to sit comfortably in that range.

If I were testing the boat on my own with a lightish load I would be looking to be at the top end of the WOT, ie 5800rpm so that when you then add some people and equipment you will sit comfortably in the middle of that range.

It's important that you have the rpm guage so you know where you are.
Logged
bigboy
Guest
« Reply #9 on: August 01, 2008, 07:54:25 CET »

Skip where can the RPM gauge be connected to please ?
Logged
skip
Administrator
Active User
******
Offline Offline

Posts: 3952



WWW
« Reply #10 on: August 01, 2008, 09:36:22 CET »

It has to go into the wiring loom within the engine where there should be a connector. I need to investigate the same thing with mine in order to check it as well.
Logged
Pages: [1]
  Print  
 
Jump to:  

Recent Posts
[August 21, 2023, 14:47:46 CET]

[August 21, 2023, 14:43:36 CET]

[February 19, 2023, 22:21:25 CET]

[May 13, 2022, 11:24:21 CET]

[April 26, 2022, 12:29:18 CET]

by Fila
[August 27, 2021, 11:38:53 CET]

by Fila
[August 27, 2021, 10:01:12 CET]

[August 26, 2021, 08:36:30 CET]

by skip
[June 13, 2021, 19:46:39 CET]

[April 18, 2021, 15:54:53 CET]

[March 30, 2021, 14:25:37 CET]

[March 12, 2021, 09:27:01 CET]

[February 05, 2021, 19:54:44 CET]

by skip
[January 10, 2021, 22:11:26 CET]
Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines | TinyPortal v0.9.8 © Bloc

Valid XHTML 1.0! Valid CSS! Dilber MC Theme by HarzeM