Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 25-04-2014, 07:11   #1
Registered User

Join Date: Nov 2011
Posts: 196
Johnson 9.9 Outboard Prop Pitch?

I am trying to replace the prop for my 2005 Johnson 9.9 2 stroke outboard that I use on an older 9ft, soft bottom Avon inflatable. I find what I need online but I have to choose a pitch I have no idea, the current prop is original and I don't recall anyone discussing pitch when we bought it, no markings to be found, and although we have a cheapie tachometer I don't think we would get helpful info from this chipped, cruddy old prop. So, I know it's a 9 1/2" 3 blade, but should the pitch be 7" 8" 9" 10"?

I don't need performance/speed (ha ha). Just average speed/oomph for tooling around. Any ideas? I was thinking of using 8" pitch but that is just a guess.
__________________

__________________
Svdestiny is offline   Reply With Quote
Old 25-04-2014, 07:23   #2
Registered User

Join Date: Feb 2009
Posts: 1,848
Re: Johnson 9.9 outboard prop pitch?

By the 7pitch
it will get you more acceleration
__________________

__________________
motion30 is offline   Reply With Quote
Old 25-04-2014, 07:30   #3
Registered User

Join Date: Nov 2011
Posts: 196
Re: Johnson 9.9 outboard prop pitch?

Thank you thank you thank you. It's been driving me crazy!
__________________
Svdestiny is offline   Reply With Quote
Old 25-04-2014, 07:50   #4
Registered User

Join Date: Oct 2009
Posts: 648
Re: Johnson 9.9 outboard prop pitch?

I had a 5 hp Nissan 2 stroke and I was not happy with the original prop which came with it, so I exchanged to for another prop. I wanted to be able to plane that inflatable with me at 200lbs and my wife at 120 and it was not possible with that original prop. I don't remember the pitch involved on either, but I'm pretty sure that I went with the highest pitch. And while it did not accelerate as fast as the lower pitch, it did obtain a higher speed thus allowing us to plane with that much weight.
__________________
lancelot9898 is offline   Reply With Quote
Old 25-04-2014, 08:02   #5
Registered User

Join Date: Nov 2011
Posts: 196
Re: Johnson 9.9 outboard prop pitch?

I don't need to plane (would probably toss the dogs off ). I just need a pitch that makes the poor old Johnson happy.
__________________
Svdestiny is offline   Reply With Quote
Old 25-04-2014, 10:36   #6
Registered User

Join Date: Dec 2008
Location: Oriental, NC
Boat: Mainship Pilot 34
Posts: 1,429
Re: Johnson 9.9 outboard prop pitch?

Buy the smallest (flattest) pitch as others have said. I assume that you are driving an inflatable. These don't need a course pitch as they won't go that fast anyway. They nead a flat pitch prop for thrust while accelerating.

I downsized the prop on my Nissan 9.9 hp 2 cycle. Before I could only plane with two on board. With the flatter pitch prop I can plane with 3 and a 40 lb dog and groceries.

David
__________________
djmarchand is offline   Reply With Quote
Old 25-04-2014, 10:54   #7
Registered User

Join Date: Nov 2011
Posts: 196
Re: Johnson 9.9 outboard prop pitch?

Huh. I actually found a local (marathon fl) inflatable parts guy who seems to know! He says that the orig outboard came with a 9" pitch. Now I just have to decide if I want to go smaller, ir bigger based on some good advice here. I'm leaning to smaller....

Thanks to EVERYONE
__________________
Svdestiny is offline   Reply With Quote
Old 25-04-2014, 18:43   #8
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 17,062
Re: Johnson 9.9 outboard prop pitch?

if you don't want to go fast, go with the flatter prop, with a flat prop it will pull like a tug boat, but you will give up speed most likely. should be easier on the old motor as long as you don't over rev it.
__________________

__________________
a64pilot is offline   Reply With Quote
Reply

Tags
outboard, pitch

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Prop Pitch on Dinghy By Invitation Propellers & Drive Systems 6 10-08-2012 05:10
Prop Pitch Adjustment Charlie Propellers & Drive Systems 29 10-02-2011 21:15
Higher Prop Pitch/Lower RPM Nirvava Engines and Propulsion Systems 8 02-12-2010 18:25
For Sale: Kiwi Prop 18.5'' Variable Pitch TOM Classifieds Archive 0 02-09-2009 02:48
Prop Size and Pitch? ciclon1942 Propellers & Drive Systems 17 26-05-2009 06:50



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 03:26.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.