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Modifing direct drive to gear reduction



How hard and what would need to be done to convert my direct drive Caddy 15' Rivermaster to a gear reduction boat? Would the engine handle it or would I have to change engines also. Do you have to modify the rigging? How much would it cost for someone to do it? I have started saving my mad money for one of Waterthunders motors. BUT in the meantime I can buy a gear reduction unit, have it, and run for a year or so. Or is it even worth the time and trouble. Just trade it? I am very happy at how this boat handles in deep water. You can dive off the sides when the boat is stoped in deep water. Feeling safe is worth a fortune. It is what you all call a ride boat. Most of my running is in deep water. But I would love to pull up to the landing and dry load this boat, or know I can run dry if I go to Melbourne and run where I grew up. A little info from my last posts is, I changed my prop to a 0 and found out that 0 is 0 and all I did was sit there when I tried to go. I backed it up to the 1 mark and can turn 2150 rpm and no more. I changed the timing chain and bolted the hub. The timing is set at 34 deg. total but need to back off that a litthl as it is slow starting when hot. I will try a 1/2 after this week end. Don't get me wrong I love this boat but always looking for a little better.
KJ, sounds like you may have an engine problem. I dont know much about your prop, but with my direct drive cad, I could turn a 78x34 paddle prop around 2800, and a 6 blade warp drive around 3100 rpm. The more rpms around 3000 you can get, the closer you are in the peak HP and tourque curve for that motor. I increased the performance of my motor by using a special ground cam, a holley 600 square bore carb that was supposed to be for low rpm applications(gained 300 rpm from standard spead bore 600 carb)also if you dont have headers they help and HEI ignition. also be careful advancing the timing I had a problem breaking starters due to kickback. This application on a 13' glass hull would run the hill with 3 people and coolers, just wouldnt run the hill real fast.
I saw a 15 ft river master with a 2 blade power shift all ss rigging run up the dike down the dike any where he wanted to go and it had a 500 caddie.he told me that the prop made all the diffrence in the world. I've herd that alot latley.

Some time ago I gave you the number for Greg Abbott of new Port Richey, FL. He has the exact boat and prop you have and runs dry with ease. IM me or leave me a message here and I will give it to you once again.

There is something else going on here. Plenty of 15' Rivermasters run dry many places with direct drive 472 / 500 Caddis. No auto direct drive will ever run dry as good as a hot reduction gear set up or as a small boat with aircraft power.

Powershift Patty has the data for you on reductions gear or belt drives to make the most of your Caddi if that is the route you choose. There should be gobs of torque that way.

Check out the Caddi Upgrades thread. I have seen two different 350s (both my son's) that had worn out cam shafts and they just would not pull under a load. You need to hook up with a Caddi man to check nder the rocks. There is something there.
K jc Too answer your original question I did convert my direct drive to gear drive.. and it was a good project. I had to cut the engine stand in two and take out enough height to make up for the height of the gear drive then i had to move the whole thing forward to make up for the extra length. I had to relocate the gas tank to balnace the boat again and I was smart enough to leave some adjustment room to adjust the pitch of the motor. All in all it was fairly easy but I was workin with square mild steel tubing and had a good grinder to smooth out the welds. It got me by for a while but my motor was not strong back then. It basically was a stock 350 with rv cam and fuelie heads edelbrock 600 carb. If you go to one of water thunders motors please get a stand built correctly. My motor is not as strong as one of his and flooring it on the hill and having the mounts break and the stand bend then the prop comes through the cage and the motor hits you in the back is not what I called fun. My stand was built by a good company but runnin the hill took its toll and all the warning I had was a loud snap at the stop before the final one. I looked it all over and saw nothing wrong so off we went runnin more dry ground bouncin all over the place and then at 2 am as I watched everyone fading off in the darkness my world lit up. luckily they stopped again and saw my flares but I had to wait till I heard them stopping and luckily they were looking back my way. I was sittin and enjoying the moonlight with my lady and didnt leave when they all left. It was a long night but made some new friends LOL.
Country - "I was sittin and enjoying the moonlight with my lady"

Sounds like the airboat itch to me - just gotta keep scratchin it.

Been there, done that, broke down after, too. Ain't airboatin' great? [/i]