Thread: 2 speed
09-25-2009, 05:50 PM #1
- Join Date
- Sep 2009
Just purchased a cheap '96 Polaris Sl900 with a whopping 47 hrs on it. Bought it off of a good friend who purchased it new then left it sit for years at a time. Picked it up for $181.56 (cost of getting it to start at a dealership he took it to). After more tinckering to get it to "run" not just "start", it runs well on the river. Was wondering if anyone tried to put at least a 2 speed into one of these pwcs. Instead of screaming down the river at 6k+ rpm it would be cool to switch to a higher gear for topend. Had some concerns over impeller speed though. Tried searching couldn't pull up anything.
09-25-2009, 09:28 PM #2
I'm not up on the technical terms.....a boat ain't a car. Shift into overdrive in a boat and you won't be making enough power to turn the prop.
09-25-2009, 09:36 PM #3
He is probably correct. The current tune of any engine in a watercraft has it's power band shifted upward (porting/timing on 2 strokes, cam/timing selections on 4strk) to make transmission shifting a very tough project. If you did get it right, that might be cool. Add in the weight, complexity and tuning, and you might end up with a much heavier form of what you started with.
I'd love to see someone make it work... Not sure you could.
If you want to make your watercraft more enjoyable, then fix the problems with it first. A SL900 SHOULD be cruising at 6500rpm's or so, with very snappy acceleration.
Slap in a 1200cc motorcycle engine with transmission and let me know how it turns out.
09-26-2009, 10:05 AM #4
welcome to the forum...
There is a close balance of matched parts that makes the ski perform as it does,,
To do what you asking would require alot of torque, the motor you have in the ski is for making horsepower, hence why it revs..
now maybe if you can get a light enough diesel,,, that would be something.....
09-26-2009, 10:38 AM #5
How about a GM 2-speed trans without the bellhousing cover off it?. It could fit in there pretty easily I would think. They do make 2-speed boat props, iv'e seen. When the rpm's get high enough, the inside of the propellor "shifts" into the higher gear. And the blades change orientation.
Same motor, same everything, just shifts at a certain speed.
Slap a 1200 in it for power. it will move regardless of how much power loss by weight or design flaws. Run a shaft to a REAL 2-speed prop and a rudder control.. It should work. Remeber that 1 post with the surface prop on it and a mazda engine? that thing flew! Welcome to the hulk.!!
Last edited by bowsniper; 10-01-2009 at 07:13 PM.
09-26-2009, 10:49 AM #6
way off topic....
Where is that catholic school and do they have a need for a new maintenance man?
09-26-2009, 02:07 PM #7
- Join Date
- Sep 2009
Thanks all! It was just something I was thinking about, can't ever leave well enough alone. Oh, and I second the maintenance position!
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