OMC King Cobra LH / CCW prop! pref. 24+ pitch
04-19-2012 | 10:50 PM
#1
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From: Chantilly, VA
OMC King Cobra LH / CCW prop! pref. 24+ pitch
In a perfect world I'd get a 15.25" diameter 4 blade 24 pitch LEFT rotation for an OMC King Cobra, but that's asking a bit much. If anyone has one of these things sitting around, let me know. I'm willing to try anything 14.75" dia and up, and/or 23 pitch and up.
Since this is the cone clutch King Cobra, I can always change the rotation if I need to - so if you've got the perfect prop and she's a RH rotation I'll consider it as well.
Please email me at alex (at) athomasphoto.com as I might miss the PM, thanks!!
Since this is the cone clutch King Cobra, I can always change the rotation if I need to - so if you've got the perfect prop and she's a RH rotation I'll consider it as well.
Please email me at alex (at) athomasphoto.com as I might miss the PM, thanks!!
04-20-2012 | 12:24 AM
#2
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Joined: Mar 2008
Posts: 3,613
Likes: 375
From: Traverse City MI
In a perfect world I'd get a 15.25" diameter 4 blade 24 pitch LEFT rotation for an OMC King Cobra, but that's asking a bit much. If anyone has one of these things sitting around, let me know. I'm willing to try anything 14.75" dia and up, and/or 23 pitch and up.
Since this is the cone clutch King Cobra, I can always change the rotation if I need to - so if you've got the perfect prop and she's a RH rotation I'll consider it as well.
Please email me at alex (at) athomasphoto.com as I might miss the PM, thanks!!
Since this is the cone clutch King Cobra, I can always change the rotation if I need to - so if you've got the perfect prop and she's a RH rotation I'll consider it as well.
Please email me at alex (at) athomasphoto.com as I might miss the PM, thanks!!
4 Blade stainless
OMC King cobra
Left rotation
21-25 pitch? Can not remember and its driving me crazy!
04-20-2012 | 04:43 AM
#3
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Joined: Mar 2002
Posts: 4,472
Likes: 2,108
From: Milton, Fla!
Find a pair of Bravo 1's and drill them for the OMC. I do it all the time for my hot rod JohnRudes, it's easy.
Flip the prop upside down, put a 1" hole saw in a drill, WD the hole/hub for a drilling aid and remove approx. 50% of the splines from rear to front. 99% of hubs are brass so they drill easily.
The only difference between the two are the Merc's prop shafts have much longer splines on them compared to the OMC's which are much shorter (stronger shaft). Shaft diameter is same (assuming standard shaft and not the newer big shaft) as is spline sizing and count.
Same for Yamaha and Suzuki. I've run them all on my JohnRudes.
Many of them will require a different thrust washer to get correct placement on shaft but I have a box of various washers, spacers and shims for this. The prop/motor doesn't care "how" you do it, just that it's in the correct position to bolt up.
To do your first one, just flip you OMC prop upside down beside the Merc and compare spline length/depth. Take out a bit at a time until they match. It will take some clean up work at the entrance to your now squared of entrance to the splines but it will work. One trick I do for this is start the prop on the shaft backwards, just enough to engage the splines and then rock the prop back and forth in a circular motion.
I've done probably 50 this way and never had an issue.
What boat are you running these in? If you are running it hard, I'd also "pin the carrier' which I (and most JohnRude) consider mandatory on a OMC case. This means through bolting the prop shaft bearing carrier and the lower unit housing. I did both mine on 24' twin O/B Sonic.
PM me for my # if you need help and I'd be glad to walk you through either/both.
I recently did a post on another site about pinning the carrier. OMC cases get a bad rap in Hi Perf applications but if pinned and w/synthetic fluid I've not had a failure and I ABUSE my junk.
Oh, one thing I forgot about running I/O wheels on an O/B. Many of the I/O wheels do not have exhaust reliefs in the prop hubs and O/B's need these since we don't have through transom exhaust reliefs. First set I ran on mine were a pig out of the hole until I figured this out. I'm having them drilled as the stainless is too hard for my Buffy and Jody drill bits
Flip the prop upside down, put a 1" hole saw in a drill, WD the hole/hub for a drilling aid and remove approx. 50% of the splines from rear to front. 99% of hubs are brass so they drill easily.
The only difference between the two are the Merc's prop shafts have much longer splines on them compared to the OMC's which are much shorter (stronger shaft). Shaft diameter is same (assuming standard shaft and not the newer big shaft) as is spline sizing and count.
Same for Yamaha and Suzuki. I've run them all on my JohnRudes.
Many of them will require a different thrust washer to get correct placement on shaft but I have a box of various washers, spacers and shims for this. The prop/motor doesn't care "how" you do it, just that it's in the correct position to bolt up.
To do your first one, just flip you OMC prop upside down beside the Merc and compare spline length/depth. Take out a bit at a time until they match. It will take some clean up work at the entrance to your now squared of entrance to the splines but it will work. One trick I do for this is start the prop on the shaft backwards, just enough to engage the splines and then rock the prop back and forth in a circular motion.
I've done probably 50 this way and never had an issue.
What boat are you running these in? If you are running it hard, I'd also "pin the carrier' which I (and most JohnRude) consider mandatory on a OMC case. This means through bolting the prop shaft bearing carrier and the lower unit housing. I did both mine on 24' twin O/B Sonic.
PM me for my # if you need help and I'd be glad to walk you through either/both.
I recently did a post on another site about pinning the carrier. OMC cases get a bad rap in Hi Perf applications but if pinned and w/synthetic fluid I've not had a failure and I ABUSE my junk.
Oh, one thing I forgot about running I/O wheels on an O/B. Many of the I/O wheels do not have exhaust reliefs in the prop hubs and O/B's need these since we don't have through transom exhaust reliefs. First set I ran on mine were a pig out of the hole until I figured this out. I'm having them drilled as the stainless is too hard for my Buffy and Jody drill bits
Last edited by Twin O/B Sonic; 04-20-2012 at 04:47 AM.
05-14-2012 | 03:29 PM
#4
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Joined: Mar 2012
Posts: 27
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From: Chantilly, VA
Find a pair of Bravo 1's and drill them for the OMC. I do it all the time for my hot rod JohnRudes, it's easy.
Flip the prop upside down, put a 1" hole saw in a drill, WD the hole/hub for a drilling aid and remove approx. 50% of the splines from rear to front. 99% of hubs are brass so they drill easily.
The only difference between the two are the Merc's prop shafts have much longer splines on them compared to the OMC's which are much shorter (stronger shaft). Shaft diameter is same (assuming standard shaft and not the newer big shaft) as is spline sizing and count.
Same for Yamaha and Suzuki. I've run them all on my JohnRudes.
Many of them will require a different thrust washer to get correct placement on shaft but I have a box of various washers, spacers and shims for this. The prop/motor doesn't care "how" you do it, just that it's in the correct position to bolt up.
To do your first one, just flip you OMC prop upside down beside the Merc and compare spline length/depth. Take out a bit at a time until they match. It will take some clean up work at the entrance to your now squared of entrance to the splines but it will work. One trick I do for this is start the prop on the shaft backwards, just enough to engage the splines and then rock the prop back and forth in a circular motion.
I've done probably 50 this way and never had an issue.
What boat are you running these in? If you are running it hard, I'd also "pin the carrier' which I (and most JohnRude) consider mandatory on a OMC case. This means through bolting the prop shaft bearing carrier and the lower unit housing. I did both mine on 24' twin O/B Sonic.
PM me for my # if you need help and I'd be glad to walk you through either/both.
I recently did a post on another site about pinning the carrier. OMC cases get a bad rap in Hi Perf applications but if pinned and w/synthetic fluid I've not had a failure and I ABUSE my junk.
Oh, one thing I forgot about running I/O wheels on an O/B. Many of the I/O wheels do not have exhaust reliefs in the prop hubs and O/B's need these since we don't have through transom exhaust reliefs. First set I ran on mine were a pig out of the hole until I figured this out. I'm having them drilled as the stainless is too hard for my Buffy and Jody drill bits
Flip the prop upside down, put a 1" hole saw in a drill, WD the hole/hub for a drilling aid and remove approx. 50% of the splines from rear to front. 99% of hubs are brass so they drill easily.
The only difference between the two are the Merc's prop shafts have much longer splines on them compared to the OMC's which are much shorter (stronger shaft). Shaft diameter is same (assuming standard shaft and not the newer big shaft) as is spline sizing and count.
Same for Yamaha and Suzuki. I've run them all on my JohnRudes.
Many of them will require a different thrust washer to get correct placement on shaft but I have a box of various washers, spacers and shims for this. The prop/motor doesn't care "how" you do it, just that it's in the correct position to bolt up.
To do your first one, just flip you OMC prop upside down beside the Merc and compare spline length/depth. Take out a bit at a time until they match. It will take some clean up work at the entrance to your now squared of entrance to the splines but it will work. One trick I do for this is start the prop on the shaft backwards, just enough to engage the splines and then rock the prop back and forth in a circular motion.
I've done probably 50 this way and never had an issue.
What boat are you running these in? If you are running it hard, I'd also "pin the carrier' which I (and most JohnRude) consider mandatory on a OMC case. This means through bolting the prop shaft bearing carrier and the lower unit housing. I did both mine on 24' twin O/B Sonic.
PM me for my # if you need help and I'd be glad to walk you through either/both.
I recently did a post on another site about pinning the carrier. OMC cases get a bad rap in Hi Perf applications but if pinned and w/synthetic fluid I've not had a failure and I ABUSE my junk.
Oh, one thing I forgot about running I/O wheels on an O/B. Many of the I/O wheels do not have exhaust reliefs in the prop hubs and O/B's need these since we don't have through transom exhaust reliefs. First set I ran on mine were a pig out of the hole until I figured this out. I'm having them drilled as the stainless is too hard for my Buffy and Jody drill bits
It's going on a 24' Donzi w/ 490hp high compression 454, through the "daddy" king cobra drive (I haven't heard any requirements for thru-bolting or strengthening, there was a guy running a twin turbo CBB at 780hp for a while and blew like 3 engines before selling the boat with the still-original king cobra haha).
offshorexcursion - let me know what you have sitting around, I wouldn't mind a genuine OMC-fit prop to have laying around.
05-15-2012 | 04:07 AM
#5
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Joined: Mar 2002
Posts: 4,472
Likes: 2,108
From: Milton, Fla!
Be very, very careful putting that much power through that drive. That's the same lower unit they ran on their 300 HP O/B's and was one of the issues with longevity.
And yeah, if you have replaceable hubs you're done.
I'm playing w/a set of Bravo 1's on my Johnrudes that I just changed hubs on.
And yeah, if you have replaceable hubs you're done.
I'm playing w/a set of Bravo 1's on my Johnrudes that I just changed hubs on.
06-19-2012 | 10:15 AM
#6
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Joined: Mar 2008
Posts: 3,613
Likes: 375
From: Traverse City MI
Heres what I have for sale. HC CL22L Q IV. It came with a used King Cobra I bought for my old boat that could bearly turn a 19P 3 blade. Its been a while but I thought the splines fit on the king cobra shaft. Not sure if the hub could be changed out for a bravo or not. Good condition 4 blade left hand hydromotive.
Thanks
Kevin
231-534-5060
Thanks
Kevin
231-534-5060
