SouthernGypsy
Recruit
- Joined
- Jun 26, 2009
- Messages
- 2
I recently had to have the outdrive replaced but the only one they could find had a different ratio and now my original props are not handling right... I.e. Now has lots of noticable prop slip.
General Boat info:
1994 Four Winns Horizon 210SS Signature Series
21'6" Length Runnabout Class Bowrider
7'9" Beam
3300-3340lbs Dry Weight
50 Gallon Fuel Tank
Rated for 10 passengers and 1800 lbs.
We usually average 2-4 people on board, the ancor and 100 foot of rope, several blow up water toys, 6 or so life vest, a set of ski's, several tow and ski ropes, a spare stainless prop, a small tool kit, large first aid kit, several towels and the built-in cooler full of drinks and ice.
Powertrain info:
5.8L MPFI V8 (351cid)
240-260 original HP (which one seems to depend on what reference your looking at) but I bought the boat in the fall of 2005 with a hole in the engine because the original owner had moved to where it freezes at night sometimes in the winter from a place where it never froze and didn't know he needed to winterize with antifreeze. So I bought it and put in a brand new High Output replacement crate engine in the winter of 2006 and it's probably now closer to 280-300HP now but don't remember exact rating.
WOT should be 4400-4600 according to manufacturer, the same on both the original and the new engine.
Original gear ratio was 1.51:1
Original prop was a 19 pitch (don't know diameter) aluminum.
Original top speed according to Four Winns was supposed to be 51-53 MPH.
Before using the boat just after getting the new engine in I also replaced the original and somewhat beat up 19 pitch aluminum prop with a Michigan Wheel Rapture II XHS 21x14.25 3 Blade Stainless and this gave me a WOT of 4400 RPM and a top speed of 55 MPH.
I also got a spare prop that's a Michigan Wheel Apollo 4-Blade XHS that's a 22 pitch and I believe a 14.0 diameter though not sure about the diameter. The 4 blade 22 pitch Apollo didn't seem to make much difference over the 3 blade 21 pitch Rapture... MAYBE a hair better hole shot and a very slight dip in top speed but nothing really noticable.
All of my speeds BTW are tested with a GPS, not my speedo, even though they are almost always within a couple of MPH of each other once I'm up on plane.
So... at the start of this summer my ring and pinon cracked and also ruint the lower casing, they said the original owner probably hit something hard years ago and it took this long for the tiny fracture to break out since I know I've never hit anything with it and my props both look brand new, plus have the XHS hub system in them so if I'd hit anything very hard the prop should have spun on the rubber hub before doing damage to the drive.
The problem is the OMC Cobra SX series drives are getting hard to find and they ended up installing one with a different gear ratio, even though it looks identical... according to the tag on the side it's a 1.85:1 gear ratio, where-as the original was a 1.51:1 ratio. Oh, I also had them check the gimbal bearing (whcih was replaced last spring anyways), put in new U-joints, and check the engine alignment, since they had the drive off anyway. They used the proper full-synthetic lube and checked out the new drive as well, testing it in the shop, though not on water.
So now it vibrates and makes a growling noise with the 3 blade except at very specific trim levels/speeds. The growl of prop slip. My RPM's was showing up in the upper 5,000's range and my top speed was down in the low 40's, about 43 I think though the lake was mildly choppy that day in places.
I had the tech come out to the lake and drive it with me and he confirmed that's all it was. We tried a brand new 19 pitch alumunum prop that he had
and it didn't make much difference. Then we put on my back up prop, the 22 pitch 4 blade Apollo. It got better and on plane with the trim set right the growl from the prop slip goes away but when you turn it's back, and the amount of trim range you have (up OR down) that you dont get slippage is very limited. With the Apollo I am now down some in RPM's though can't seem to get one steady reading, but was able to get to 46 MPH one evening when the lake was very calm and I had the trim just right.
The tech had said I needed a prop with more pitch, which makes sense. He estimated maybe as much as 27, though that sounds like a lot to me. So this evening I've tried to find a formula on the internet but can't find one to tell me how much pitch I do need to correct back for the gear change from the original 1.51 gears to the new 1.85 gears.
I tried several prop selectors online and most don't seem to work very good, they just assume original gear ratios when I tell it what kind of powertrain that I have and tell me I need a 19-21 pitch, though one listed those but also noted maybe as much as 25 for top speed with a light load, or they have me put in my data and then tell me *I* entered an error when I tell them the current top speed and pitch. Mercury Marines when I tell it my current prop was 21 or 22 pitch and I am only getting 45-46 MPH it comes back and tells me that there is an Error because the Top Speed or the Current Props pitch is "out of expected range" .... Well DUH! That's why I was trying to use their prop selector in the first darn place, cause they're out of expected range!! That's the whole problem!
Anyone know the formula or way to figgure this out?
Buying a prop, such as a 25 pitch which is my first instinct, just to see if it is correct could get expensive and we don't have any of those places around us who let you try one before you buy it or exchange it afterwards if your a little off.
General Boat info:
1994 Four Winns Horizon 210SS Signature Series
21'6" Length Runnabout Class Bowrider
7'9" Beam
3300-3340lbs Dry Weight
50 Gallon Fuel Tank
Rated for 10 passengers and 1800 lbs.
We usually average 2-4 people on board, the ancor and 100 foot of rope, several blow up water toys, 6 or so life vest, a set of ski's, several tow and ski ropes, a spare stainless prop, a small tool kit, large first aid kit, several towels and the built-in cooler full of drinks and ice.
Powertrain info:
5.8L MPFI V8 (351cid)
240-260 original HP (which one seems to depend on what reference your looking at) but I bought the boat in the fall of 2005 with a hole in the engine because the original owner had moved to where it freezes at night sometimes in the winter from a place where it never froze and didn't know he needed to winterize with antifreeze. So I bought it and put in a brand new High Output replacement crate engine in the winter of 2006 and it's probably now closer to 280-300HP now but don't remember exact rating.
WOT should be 4400-4600 according to manufacturer, the same on both the original and the new engine.
Original gear ratio was 1.51:1
Original prop was a 19 pitch (don't know diameter) aluminum.
Original top speed according to Four Winns was supposed to be 51-53 MPH.
Before using the boat just after getting the new engine in I also replaced the original and somewhat beat up 19 pitch aluminum prop with a Michigan Wheel Rapture II XHS 21x14.25 3 Blade Stainless and this gave me a WOT of 4400 RPM and a top speed of 55 MPH.
I also got a spare prop that's a Michigan Wheel Apollo 4-Blade XHS that's a 22 pitch and I believe a 14.0 diameter though not sure about the diameter. The 4 blade 22 pitch Apollo didn't seem to make much difference over the 3 blade 21 pitch Rapture... MAYBE a hair better hole shot and a very slight dip in top speed but nothing really noticable.
All of my speeds BTW are tested with a GPS, not my speedo, even though they are almost always within a couple of MPH of each other once I'm up on plane.
So... at the start of this summer my ring and pinon cracked and also ruint the lower casing, they said the original owner probably hit something hard years ago and it took this long for the tiny fracture to break out since I know I've never hit anything with it and my props both look brand new, plus have the XHS hub system in them so if I'd hit anything very hard the prop should have spun on the rubber hub before doing damage to the drive.
The problem is the OMC Cobra SX series drives are getting hard to find and they ended up installing one with a different gear ratio, even though it looks identical... according to the tag on the side it's a 1.85:1 gear ratio, where-as the original was a 1.51:1 ratio. Oh, I also had them check the gimbal bearing (whcih was replaced last spring anyways), put in new U-joints, and check the engine alignment, since they had the drive off anyway. They used the proper full-synthetic lube and checked out the new drive as well, testing it in the shop, though not on water.
So now it vibrates and makes a growling noise with the 3 blade except at very specific trim levels/speeds. The growl of prop slip. My RPM's was showing up in the upper 5,000's range and my top speed was down in the low 40's, about 43 I think though the lake was mildly choppy that day in places.
I had the tech come out to the lake and drive it with me and he confirmed that's all it was. We tried a brand new 19 pitch alumunum prop that he had
and it didn't make much difference. Then we put on my back up prop, the 22 pitch 4 blade Apollo. It got better and on plane with the trim set right the growl from the prop slip goes away but when you turn it's back, and the amount of trim range you have (up OR down) that you dont get slippage is very limited. With the Apollo I am now down some in RPM's though can't seem to get one steady reading, but was able to get to 46 MPH one evening when the lake was very calm and I had the trim just right.
The tech had said I needed a prop with more pitch, which makes sense. He estimated maybe as much as 27, though that sounds like a lot to me. So this evening I've tried to find a formula on the internet but can't find one to tell me how much pitch I do need to correct back for the gear change from the original 1.51 gears to the new 1.85 gears.
I tried several prop selectors online and most don't seem to work very good, they just assume original gear ratios when I tell it what kind of powertrain that I have and tell me I need a 19-21 pitch, though one listed those but also noted maybe as much as 25 for top speed with a light load, or they have me put in my data and then tell me *I* entered an error when I tell them the current top speed and pitch. Mercury Marines when I tell it my current prop was 21 or 22 pitch and I am only getting 45-46 MPH it comes back and tells me that there is an Error because the Top Speed or the Current Props pitch is "out of expected range" .... Well DUH! That's why I was trying to use their prop selector in the first darn place, cause they're out of expected range!! That's the whole problem!
Anyone know the formula or way to figgure this out?
Buying a prop, such as a 25 pitch which is my first instinct, just to see if it is correct could get expensive and we don't have any of those places around us who let you try one before you buy it or exchange it afterwards if your a little off.
