Reply
 
Thread Tools Search this Thread
 
Old 14 July 2004, 04:55   #1
Member
 
Country: Greece
Town: ATHENS
Boat name: SUN KISS II
Make: Nuova Bat 9 Falcon -
Length: 5m +
Engine: Outboard Mercury 115
Join Date: Jun 2001
Posts: 639
Send a message via Skype™ to batfalcon
Which prop ?

I have a "Bat 9 Falcon X" rib (5,3 m) powered by a Merc 115. The engine was delivered with an Aluminun 19x13 prop and worked fine with this rig, exept the fact that I added to many things (weights) during the past years, so I was forced to pitch down to 17x13 1/4. With this prop the engines tops at 5.000 rpm (don't remember the speed).
Recently I was given a standard Yamaha steel prop 19x13, which ffits fine and I tested last weekend.
I get 5.200 rpm (!!!) with this prop BUT I think that the speed had decreased. In fact the top speed now is 35,8 knots (according to gps).
I also have measured the speed at 4.500 prm which is 28,5 knots.
Any suggestions on which prop is the most recommened please ?
__________________

__________________
Michael a.k.a "Bat Falcon"

batfalcon is offline   Reply With Quote
Old 15 July 2004, 05:49   #2
Member
 
Country: Greece
Town: ATHENS
Boat name: SUN KISS II
Make: Nuova Bat 9 Falcon -
Length: 5m +
Engine: Outboard Mercury 115
Join Date: Jun 2001
Posts: 639
Send a message via Skype™ to batfalcon
It's obvious ...

... that either none around this forum is able to answer my questions, or they are insignificant. Then again maybe none saw them ....
__________________

__________________
Michael a.k.a "Bat Falcon"

batfalcon is offline   Reply With Quote
Old 15 July 2004, 15:47   #3
Member
 
Country: UK - England
Town: Looe
Make: Delta
Length: 4m +
Engine: Mercury
Join Date: Apr 2004
Posts: 1,335
Is your engine 2 or 4 stroke? A 2 stroke should rev to 5500rpm and the 4 stroke should rev to 6000. It sounds like the Yamaha prop you have got is slipping, check the bush in the middle of the prop. If it has play in it then that could cause your problem.
The general rule for props is for each pitch of prop you will go up or down about 200 rpm.Maybe with all your weight you should try a 15" pitch. If its a four stroke maybe try a 13" pitch.
__________________
Turbodiesel is offline   Reply With Quote
Old 16 July 2004, 05:19   #4
Member
 
Country: Greece
Town: ATHENS
Boat name: SUN KISS II
Make: Nuova Bat 9 Falcon -
Length: 5m +
Engine: Outboard Mercury 115
Join Date: Jun 2001
Posts: 639
Send a message via Skype™ to batfalcon
Turbodiesel

It's a 2 stroke.
The Yam prop is definetly not slipping. If it was the situation would have been worse everyday, which isn't happening.
Any other ideas ?
__________________
Michael a.k.a "Bat Falcon"

batfalcon is offline   Reply With Quote
Old 16 July 2004, 06:12   #5
Member
 
Country: UK - England
Town: Over here
Boat name: S.S. Nobstick
Make: Three Wise Monkeys
Length: 3m +
Engine: 44lbs of thrust....
Join Date: Nov 2003
Posts: 2,115
Talk to Julie at Steeldevelopments. She posts here, but it may help if you did proper speed/revs/weight checks to give her the information accurately. Also check your manual for max RPM. I thought that the 115 (Classic?) 2 stroker WOT maxed at 4750-5250.
__________________
Jono is offline   Reply With Quote
Old 17 July 2004, 04:09   #6
Member
 
Country: Greece
Town: Gloucetsreshire
Boat name: GATO DI MARE
Make: MAR.CO
Length: 9m +
Engine: Yamaha 200Vmax
MMSI: 235027678
Join Date: Sep 2002
Posts: 3,339
Send a message via MSN to Manos Send a message via Yahoo to Manos Send a message via Skype™ to Manos
...........or hire a 640SR LOLOL
__________________

Manos is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 08:38.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.