Prop slip around 30%, very hard to get on plane
Today, 07:44 AM
#71
Registered
This may have been covered but you did go for a "sea trial" correct? The seller got it on plane and you went for a ride? I know it's difficult to tell if there is anything peculiar about a boat you have never been on but wondering if you felt a vibration?? On your next visit to the boat, take pics of the props and also spin them with your hand and see if they wobble or not. I suppose that finding both props with the same damage is a reach but it appears that both sides have identical problems so lets start eliminating things.
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baja 33outlaw (Today)
Today, 09:20 AM
#72
Is anyone on this thread using 2" shorter lower units? I'd like to see a pic if you are. I was looking at the video again and it appears that the props are simply loosing bite and it's not a case of BOTH drives popping out of forward or the hubs spinning because IMHO the rpm would INSTANTLY go to the limiters and his does not. I had an old school press in rubber hub let go and that's what happened to me. Anyway, I thought in the interest of eliminating variables I would take a pic of my stone stock B-1 lower units with a tape measure in the pic showing the drop from both "plates" to the centerline of the prop shaft and in doing so, I now am wondering where the 2" loss in height comes from. I see the 2" between the plates, is that it?? Is there still the lower cavitation plate on a 2" shorter unit or does that just go away? FYI, the one dimension is 10-1/2" and the other is 8-1/4".
Today, 09:36 AM
#73
This may have been covered but you did go for a "sea trial" correct? The seller got it on plane and you went for a ride? I know it's difficult to tell if there is anything peculiar about a boat you have never been on but wondering if you felt a vibration?? On your next visit to the boat, take pics of the props and also spin them with your hand and see if they wobble or not. I suppose that finding both props with the same damage is a reach but it appears that both sides have identical problems so lets start eliminating things.
I don't notice any vibrations, and the props don't wobble when I've spin them while on the trailer.
Today, 10:02 AM
#74
VIP Member
VIP Member
did a sea trial, the seller drove. He slowly eased it up on plane, I don't remember if the props were blowing out slightly on him. I imagine they were, I just wasn't aware of that going on. Until I've had it in lake erie for a few weeks I can slowly get it on plane, while doing so the props are blowing out. Once it's bottom is too dirty, no matter what I do it won't plane.
I don't notice any vibrations, and the props don't wobble when I've spin them while on the trailer.
I don't notice any vibrations, and the props don't wobble when I've spin them while on the trailer.
I'm very curious about the drive shower pickups. It's something I hadn't thought of that would definitely check the boxes. I'd wager that, if they are on the wrong side, there's your culprit.
You still need to address those cone clutches. Just sayin'....
For the record, I'm contributing to learn. As much as it may seem otherwise, I am listening way more than I'm talking.
Thanks. Brad.
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baja 33outlaw (Today)
Today, 01:55 PM
#75
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Is anyone on this thread using 2" shorter lower units? I'd like to see a pic if you are. I was looking at the video again and it appears that the props are simply loosing bite and it's not a case of BOTH drives popping out of forward or the hubs spinning because IMHO the rpm would INSTANTLY go to the limiters and his does not. I had an old school press in rubber hub let go and that's what happened to me. Anyway, I thought in the interest of eliminating variables I would take a pic of my stone stock B-1 lower units with a tape measure in the pic showing the drop from both "plates" to the centerline of the prop shaft and in doing so, I now am wondering where the 2" loss in height comes from. I see the 2" between the plates, is that it?? Is there still the lower cavitation plate on a 2" shorter unit or does that just go away? FYI, the one dimension is 10-1/2" and the other is 8-1/4".
Today, 02:26 PM
#76
Registered
The area where it is shorted is below the cavitation plate and above the area of the gear case that is shaped like a bullet, where the gears and shaft are housed, they then follow the lines of the trailing edge of the gear case and remove the rear section from cavitation plate on up.
Today, 04:47 PM
#77
Registered
It sounds like the prop shaft centerline is too high. (Or, for some crazy reason he cannot trim the drive all the way in.)
~OR~ he has a set of -2" lowers making it hard to plane.
I would also add that his prop diameter "may" be too small, however, he would be hitting the rev limiter - so I do not believe this to be the case. He should easily be getting 5200-5400 RPM. Can you try a smaller pitch prop, like a 24" pitch but verify it is the same diameter. Anyone around you have one of those? Can you tell us your prop diameter?
I am in the area and I'll ask around if anyone has a 24" pitch Bravo prop. If you could get it on the trailer, someone up around us can help you check the prop shaft centerline.
These all sound like issues I would have trying to run drives / X-dim too high or too small of a prop diameter on my boat. I chose to eventually run spacers, and keep prop diameter high at 18" (surfacing drives).
Can someone confirm the X-dim or prop shaft centerline to hull bottom measurement of the stock setup?
My buddy had a 36 outlaw and it planed like a ski boat. Can you ask the prior owner if he ever had the drives raised up??? OR, knows of shorty lowers (-2") being installed?
~OR~ he has a set of -2" lowers making it hard to plane.
I would also add that his prop diameter "may" be too small, however, he would be hitting the rev limiter - so I do not believe this to be the case. He should easily be getting 5200-5400 RPM. Can you try a smaller pitch prop, like a 24" pitch but verify it is the same diameter. Anyone around you have one of those? Can you tell us your prop diameter?
I am in the area and I'll ask around if anyone has a 24" pitch Bravo prop. If you could get it on the trailer, someone up around us can help you check the prop shaft centerline.
These all sound like issues I would have trying to run drives / X-dim too high or too small of a prop diameter on my boat. I chose to eventually run spacers, and keep prop diameter high at 18" (surfacing drives).
Can someone confirm the X-dim or prop shaft centerline to hull bottom measurement of the stock setup?
My buddy had a 36 outlaw and it planed like a ski boat. Can you ask the prior owner if he ever had the drives raised up??? OR, knows of shorty lowers (-2") being installed?
Last edited by frickstyle; Today at 04:51 PM.
Today, 05:45 PM
#78
VIP Member
VIP Member
JaayTeee,
I get that. But, with twins, the engines are typically counter rotating, correct? (Genuine question) Or do they just put all that gear thrust against the top cap of the LH drive?
I suppose with just 496HOs, it's probably not enough HP to really hurt anything. But, from a mechanical engineering standpoint (Which is where most of my reasoning comes from), it just seems like a bad idea to place the higher force against the weaker structure, even if failure thresholds are not exceeded.
Thanks. Brad.
I get that. But, with twins, the engines are typically counter rotating, correct? (Genuine question) Or do they just put all that gear thrust against the top cap of the LH drive?
I suppose with just 496HOs, it's probably not enough HP to really hurt anything. But, from a mechanical engineering standpoint (Which is where most of my reasoning comes from), it just seems like a bad idea to place the higher force against the weaker structure, even if failure thresholds are not exceeded.
Thanks. Brad.
SSM’s NXTs alpha’s are rotation specific
the top gear in a bravo will rotate the prop shaft ccw, the bottom will
rotate the propshaft cw
