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duckdoctor
MMT Member
Joined: Thu Dec 01, 2011 8:21 pm Posts: 17
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 GDSD RPM'S
I was wondering what a stock Go-Devil surface drives RPM's should be in the water and out of the water. It is a marine non-CDI. Right now, I am getting 4200 out of the water but only 3300 in the water (with just me in the boat)...where should they be? thanks
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Tue Sep 04, 2012 7:33 am |
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duckdoctor
MMT Member
Joined: Thu Dec 01, 2011 8:21 pm Posts: 17
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 Re: GDSD RPM'S
sorry - it is a 35hp with a brand new 3 blade prop
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Tue Sep 04, 2012 7:34 am |
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ŁukeŁeBlanc
MMT Member
Joined: Thu Aug 23, 2012 4:02 pm Posts: 37
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 Re: GDSD RPM'S
I run 4350 out of the water 3700 trimmed down and 3900-4000 trimmed up with the Marine 35 GDSD
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Tue Sep 04, 2012 7:45 am |
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Gigafowl
MMT Elite Member
Joined: Tue Jan 13, 2009 7:19 pm Posts: 6441 Location: Trinity Bay - Texas
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 Re: GDSD RPM'S
Well your governor sounds like it's set right if you get 4200 out of water...
Under power you should shoot for 3500 to 3800 to get max speeds you can set your trim knob or just press down a bit on your handle to let the prop "breathe" a bit...
If you just got it - some guys will bend their lower fins - up in the rear to get a deeper bite - often on an old prop which is blowing out they will do this a bit too much and then when you do put a new prop on it runs too deep... So straightening the lower fins might be in order... A little goes a long way so do it in small 1/8" incriments....
_________________ Eat - Sleep - Hunt ! ! !
"It is good to have an end to journey toward; but it is the journey that matters, in the end."
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Tue Sep 04, 2012 8:21 am |
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barnes_53
MMT 1000 Club
Joined: Wed Jul 18, 2012 4:14 pm Posts: 4781
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 Re: GDSD RPM'S
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Tue Sep 04, 2012 9:53 am |
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bbb
MMT 1000 Club
Joined: Wed Sep 02, 2009 2:54 pm Posts: 1554 Location: SW Georgia
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 Re: GDSD RPM'S
_________________ 19x54 Seminole Extreme with a 35hp CDI GDSD. Mikuni. Marsh Mellow. Heads. Cam.
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Tue Sep 04, 2012 11:29 am |
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ŁukeŁeBlanc
MMT Member
Joined: Thu Aug 23, 2012 4:02 pm Posts: 37
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 Re: GDSD RPM'S
I got mine on a 16x38 go devil and I get about 28-29 @ 3700rpms
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Tue Sep 04, 2012 11:49 am |
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duckdoctor
MMT Member
Joined: Thu Dec 01, 2011 8:21 pm Posts: 17
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 Re: GDSD RPM'S
My boat is a 17x54 beavertail and I'm around 230 lbs. When I first had motor, I could run around 28,29 but didn't have a tach, so I don't know what the RPM's were. The motor is getting to be around 3 years old and has been to the shop for valve repair in early 2011. The heads had to end up being replaced...too much leak off
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Tue Sep 04, 2012 3:13 pm |
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vertical_edge_800
MMT Pro Member
Joined: Thu Dec 30, 2010 5:48 am Posts: 274 Location: Palmer, Alaska
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 Re: GDSD RPM'S
Mine was running about 3600 RPM before I modified it to get into the sweet spot. It runs 4300+ now.. but the biggest pain in the butt is that trim tab. I cut mine off and welded bigger ones on to help hold it down, turns out it worked really well, until you get into the weeds, then they snag onto everything. I'm thinking about cutting them off again, welding stock type ones back on, then putting about 20 lbs of lead weight on the top of the cavitation plate to help hold it in the water. The GDSD is too much of a neutral balanced motor in my opinion.. sees like the general consensus is that it is hard to keep that prop in the water. Sorry that was a little bit of a tangent.. 3600 RPM- good to go!
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Tue Sep 04, 2012 10:19 pm |
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Robn1020
MMT 1000 Club
Joined: Mon Feb 16, 2009 6:09 pm Posts: 4232 Location: Cypress, TX
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 Re: GDSD RPM'S
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Wed Sep 05, 2012 12:44 am |
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ŁukeŁeBlanc
MMT Member
Joined: Thu Aug 23, 2012 4:02 pm Posts: 37
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 Re: GDSD RPM'S
So is there a way to help keep It in the water?
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Wed Sep 05, 2012 7:29 am |
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Gigafowl
MMT Elite Member
Joined: Tue Jan 13, 2009 7:19 pm Posts: 6441 Location: Trinity Bay - Texas
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 Re: GDSD RPM'S
_________________ Eat - Sleep - Hunt ! ! !
"It is good to have an end to journey toward; but it is the journey that matters, in the end."
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Wed Sep 05, 2012 11:01 am |
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Gigafowl
MMT Elite Member
Joined: Tue Jan 13, 2009 7:19 pm Posts: 6441 Location: Trinity Bay - Texas
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 Re: GDSD RPM'S
_________________ Eat - Sleep - Hunt ! ! !
"It is good to have an end to journey toward; but it is the journey that matters, in the end."
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Wed Sep 05, 2012 11:03 am |
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ŁukeŁeBlanc
MMT Member
Joined: Thu Aug 23, 2012 4:02 pm Posts: 37
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 Re: GDSD RPM'S
I just got a new prop I swapped from the kohler 27 to the marine 35 last week but since day one with the kohler it never really stayed in the water and it's a go devil boat
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Wed Sep 05, 2012 11:03 am |
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