polaris atv clutch on a 420cc clone

[poordad]

Hi I have found many good things on this forum so I figured I would ask the people with the information.

hear it goes I have built a buggy using a 420cc predator clone and Polaris clutches and transmission.

my question is has anybody used this setup and what kind of spring/weight setup did the best for all purpose off road driving?

I am currently running a 12t drive and a 38t driven sprocket on 24" tires.

I know I am riding the line between go kart and buggy but any help would be appreciated.

thanks

 

[landuse]

Welcome to the forum poordad. You have build a really nice buggy. I am not sure of what springs etc you should use, but someone will reply soon. It takes a while for this forum to get going. There aren't loads of active members

 

[OzFab]

I know I am riding the line between go kart and buggy but any help would be appreciated.

That's ok, we cover buggies too. Welcome to the forum.

 

[poordad]

thanks
I think it will run and ride well and I'm just trying to get the best power out to the wheels, maybe 50mph and decent uphill possibilities. if possible

 

[spyder1968]

does it have good torque now? changing the weights will make the clutch engage sooner or later than stock. if you need a bit more "outta the hole" you may want to loosen it up a bit to allow the engine to rev up a bit more before fully engaging the clutch.
how is the top speed ? do you need ALL of that speed? maybe gearing down a bit for more low end power would be the way to go.
basically....we need a bit more info......

 

[spyder1968]

sorry...just re read your second post. you haven't driven this thing yet? i would suggest at least driving it for a bit ( providing nothing seems wrong with it) before deciding to go changing the clutch rollers. i am just guessing.....but it seems like it may be over geared.
get the gearing where you want first....then fine tune the clutch to your taste

 

[Bluethunder3320]

the problem i see with that is if the polaris clutch is from a 2 stroke, it will engage at a higher RPM than your engine even reaches. i would find the specs on the clutch, engagement speeds...

looks like a nice build and good luck!

 

[poordad]

I have tested it around the yard and write now I am getting about 15mph but it has great low end pull. I know that I am not getting all of my driver (only about 1/2) but have not removed the gov, new exhaust, and jet, yet. I was hoping to be able to run in the 4,000 - 5,000 range as a top and get some decent performance at around 3,000 - 4,000 for a normal run.

now I am set up with the blue/green drive spring and 41.5g weights - black driven spring clocked at 1 & 3 with a stock helix.

The clutches are from a 325 polaris 4str and as I am learning are pretty much the same on most 2 and 4 str but are weighted and set with many different spring sets to work with the different motors.

I am thinking the next step would be to remove the gov, change the main spring to a black or softest spring made and possibly increase the drive weights?

what kind of rpm do you think it will most comfortably run @ with the governor removed?

has anyone successfully gotten performance from a polaris clutch on a 16hp clone or do you think that they are capable of running this setup?

thanks for the replies and any help/input is always appreciated

 

[fowler]

To test your clutches take a whit board marker and draw lines from your belt to the out side of the clutch

Then go hard for a bit around the yard and where the lines are erased is how high the Belt climbs

How do the Polaris stats compare to the clones
The closer the better

If u remove the governor then u may get 5 before the valves float
U could probs get 8 if u got serious and started doing some big mods

 

[Doc Sprocket]

Interesting. What did you have to do to make the driver fit on that engine shaft?

I too think that the driver's engagement RPM is very likely too high. When you start from a stop, how much throttle do you have to feed it to get moving? It probably helps quite a bit that the drive came from a 4-stroke, though.

This may be a stupid question, but are the driver and driven the correct distance apart for the belt length? If the belt is too slack you'll end up wasting revs.

The ideal setup (IMO) is to use the sled engine, but if that's not on the table, then continue on!

BTW- your buggy looks terrific! You scratch-built that? Good on ya!

 

[spyder1968]

I am very interested to see how this turns out, as I have seriously thought about using a snowmobile (or quad) cvt myself. It sounds to me like using a softer spring and heavier rollers should help your problem. You will have to experiment with spring/weight combinations. My 16hp clone (420cc lifan) with no governor revs well, but I do not know exactly how high and the valves never floated. If I had to guess I would say it is pushing close to 5000 RPMs. My motor is stock except for header and Tillotson carb.

 

[Doc Sprocket]

My 16hp clone (420cc lifan) with no governor revs well, but I do not know exactly how high and the valves never floated. If I had to guess I would say it is pushing close to 5000 RPMs. My motor is stock except for header and Tillotson carb.

Interesting. Not to jack the thread, but have you managed to clock your top speed and reverse-calculate RPM? The fact that you have no valve flutter suggests that you are limited by your gearing- which is ideal, really.

 

[spyder1968]

Clocked speed with my wifes GPS on her phone top speed seems to be 46 mph. Not really sure though as the GPS takes a few seconds to react, and at that speed I run out of room quickly. I am planning on changing the driven to a 8.5" diameter (44 mag) instead of the current 7.5" diameter for some low end power, as I do not need my current top speed but can always use more low end power. I guess I will find out if I am (or was) gear limited when I change the driven. Currently I have a 10t on the driven and a 70t on the axle (with 22" rear tires) and the kart is HEAVY!

 

[poordad]

thanks

I used a adapter from this place to fit the clutch

http://www.cartpartsplus.com/tapered-clutch-adapter.html?osCsid=e4ce4264646da5a4dd208bb332e48c49

my distance is 10.3" shaft to shaft and the belt seams to be tight but I have thought about a more adjustable mount so I can try different settings on this as well.

does anyone have a link to the clone stats so I can compare the 325 polaris and find out where I'm at.

toystory it sound like you are getting good results.
how heavy is your buggy and what kind of transmission are you running i.e. clutch or CV?

mine ways about 600lbs

I guess I will let you know if my lite spring and heaver weights work

 

[Doc Sprocket]

My first course of action would be a bit of research. I would want to know the following-

* The original pulley spacing on the donor snowmobile. For a CVT to perform correctly, this is pretty critical info. Experimentation will prove time consuming and frustrating.

* The original RPM range (engagement and redline) of the snowmobile. This will indicate whether you actually need to alter the CVT's characteristics. You may not have to, based on the first point.

My own stats (were) as follows-

Honda GX340 pretty much bone stock. Air box removed, homemade cherry bomb muffler, carb re-jetted. Governor adjust screw removed, running about 4250RPM. Comet 40 CVT, with driven retensioned to shift a bit later. Tires measuring 17" at desired inflation pressure. 4.8:1 gearing, loaded weight including driver about 450lbs. GPS and speedo verified top speed 46 MPH (72Km/h). Note that acceleration was not wonderful at that ratio. Had I not planned an engine swap, I would have geared down further, and removed the governor. This would result in better acceleration without sacrificing speed.

EDIT- I can't believe how much they charge for that dang adapter!

 

[mister twister]

didnt we already establish that this cvt is from a four wheeler?

 

[Doc Sprocket]

didnt we already establish that this cvt is from a four wheeler?

Did we? Meh- Same principles apply.

 

[poordad]

thanks for the information on your motor as this definitely helps with a baseline for expectation

My spacing is the same as the quad that the clutches came from but I may dead to add shims adjust the belt spacing on the sheave face.

the adapter is pricey but considering the price of a comet 40 and the fact that a build clone may exceed the limits, it may be worth it

its all just trial and error until it gets figured out.

 

[poordad]

Ive bean messing with my clutch and gearing lately and think I am getting closer to the ride that I am looking for.

I changed the weights on my primary to 55g from 41g with a blue/green spring and clocked my secondary at 3 on the sheave and 2 on the helix with a black secondary spring.

I have set my UNI / and strait pipe-silencer up and now I am looking at a re jet. drill and jet tomorrow, test

Is anyone running a mikuni 34mm carb and if so can you post pics of your setup?

 

[poordad]

some video of my buggy

I set the driven clutch with a black spring at 3 on the sheave and 1 on the helix

the driver has a blue/green spring and 55g weights

I removed the gov and drilled the stock carb to .040

running about 4500rpm I get about 35mph with a little left over

http://www.youtube.com/watch?v=xC36UhIeoak

http://www.youtube.com/watch?v=Ty8O0-1pzb4

http://www.youtube.com/watch?v=kGTjBlziN4Q

http://www.youtube.com/watch?v=H0xwKNScsw4