G1 Clutch RPM

[paulhut]

I have a G1 with a Polaris engine and I want more speed. Right now it does about 30mph at 5,000 RPM and gets up to full speed very quickly but I want MORE!

To go faster I am going to replace the transmission with one that has a better gear ratio. At the moment I am thinking of building one so I can control the final speed of the cart by simply changing out sprockets on the final drive.

In order to estimate the final speed of the cart I need to know the RPM of the secondary clutch when the primary is fully closed. Does anyone have any idea how fast the secondary clutch spins at full speed?

Thanks!

[slonomo]

Couple of questions:

Is the Polaris engine a 2 or 4 stroke?

Are you using the stock 2 stroke secondary clutch?

[paulhut]

The Polaris engine is a 2 cylinder 2 stroke engine and yes, I am going to use the stock clutch.

[DOOmsman]

D times pi is circumference do the math on
each clutch and you will have the ratio.

[yamarancher]

how fast you wanta go? Plowmans have a 100 hp rotary engine. that should make er go. might try a smaller secondary? delco makes a mechanical hand held tach you could check the shaft speed with.

[slonomo]

Is 5000 rpm the redline? I thought those 2 strokes were good for 8k or 9k? Maybe you just need more RPM? Rev limiter? 30 mph at 5k doesn't sound right, it ought to be faster than that. My little G1 215cc will top out at 26mph on flat ground, I'm guessing the rpm on mine to be in the 6k range but I'd be guessing. I'd think that unless you have ultra low gears in that transaxle you should be getting to 45 or 50 mph?

You'll have to find out your final drive ratio is to see if you have low gears, maybe you do.

Take belt off, take rear tires off, put a mark on the shaft of secondary clutch and a mark on the rear hub, turn secondary slowly counting the rotations until you get one full rotation on the hub. This will give you your ratio.

Once you have that, it might clue us in on what you need to do to get more speed.

[slonomo]

I'm not a snowmobile guy, but my quick research shows a Polaris 500 should max out at 7800 rpm. Not sure what engine you have but it should be close.

Also, if you can't get any more rpm out of that motor, it could be a problem with the primary clutch not shifting out all the way. Might need a rebuild on that? I assume you are using the stock polaris sled clutch? Does it look like this?

[DOOmsman]

Mark the clutch faces with a magic marker and take a ride.
Check to see how far the belt is moving under load.

[slonomo]

Originally Posted by DOOmsman

Mark the clutch faces with a magic marker and take a ride.
Check to see how far the belt is moving under load.

Good call Doom, sometimes I overthink things...

[spriddle]

I'd like to see pic's of the engine! Bet this thing could be scary!! Have you considered going with a newer rearend and getting some high speed gears. It would take a little fabbing but worth checking into. I'd go with high performance clutches both front and rear with this engine. Anything stock is going to wear out quick if your turning really high rpms. Most Polaris two strokes are nothing but bad to bone power from what I've seen. I've personally never messed with them myself but they are a heck of an engine. If we are talking a 2 stroke Polaris snowmobile engine.