formariz 11,987 #1 Posted December 8, 2020 Can someone enlighten me on the function of this pulley? Came years ago with a K241. 1 Share this post Link to post Share on other sites
slim67 2,735 #2 Posted December 9, 2020 (edited) Looks exactly like a snowmobile or golf cart driven clutch. Maybe engine drove belt to other pulley and the shaft gave it the necessary length to the driven clutch? Edited December 9, 2020 by slim67 add 3 Share this post Link to post Share on other sites
DennisThornton 4,769 #3 Posted December 9, 2020 Variable but for what? 1 Share this post Link to post Share on other sites
953 nut 55,337 #4 Posted December 9, 2020 Looks like some side force applied to the three flat studs on the outside with a throwout bearing would engage the pulley to the shaft. When I was a kid we had a rater crude engine driven manure removal device that had a rope attached to a wide shovel and a pulley that would wind the rope while you held on to the shovel for dear life. You would activate it by yanking on a rope suspended from the ceiling and you were off to the races! A ball on the rope would open the clutch when you got to the top of the ramp over the manure spreader. I sort of doubt that OSHA would approve of it. 4 Share this post Link to post Share on other sites
ebinmaine 67,704 #5 Posted December 9, 2020 Can't offer anything else but for ya gotta use it for something. Share this post Link to post Share on other sites
lynnmor 7,315 #6 Posted December 9, 2020 You have half of a variable speed drive system. The other half might be mounted on a motor. One side spreads apart while the other comes together to change speeds. 4 Share this post Link to post Share on other sites
formariz 11,987 #7 Posted December 9, 2020 31 minutes ago, lynnmor said: You have half of a variable speed drive system. The other half might be mounted on a motor. One side spreads apart while the other comes together to change speeds. Would this be it? It was on the engine. 5 Share this post Link to post Share on other sites
Pullstart 62,922 #8 Posted December 9, 2020 Yep. As it spins faster, it has weights that make it skinny up the front groove, therefore tightening the belt (just like an RJ35 vari-drive system but automatic) and making the front pulley larger diameter, then the rear gets smaller. That makes it faster and faster. It’s what allows a snowmobile to holeshot at 4500 rpms, but cruise at 2500-3500 at higher speeds. 2 4 Share this post Link to post Share on other sites
Handy Don 12,250 #9 Posted December 9, 2020 Used on mini-bikes too! My Hustler had one and that little 4hp could move off very smartly in the low gear and top out at about 30. 2 Share this post Link to post Share on other sites
formariz 11,987 #10 Posted December 9, 2020 1 minute ago, pullstart said: As it spins faster, it has weights that make it skinny up the front groove, therefore tightening the belt That would be the one on the engine? 2 minutes ago, pullstart said: then the rear gets smaller. That would be the one on the shaft? This requires a large width belt? So what controls the speed would only be the throttle? 3 Share this post Link to post Share on other sites
Handy Don 12,250 #11 Posted December 9, 2020 11 minutes ago, formariz said: That would be the one on the engine? That would be the one on the shaft? This requires a large width belt? So what controls the speed would only be the throttle? Exactly right. The offset to the engine's speed trying to skinny up the pulley width (and enlarge it effective diameter) is the load as it tries to turn the pulley. So yes, its all throttle, engine RPM, and torque. In a snowmobile they actually call them torque converters. 3 1 Share this post Link to post Share on other sites
Handy Don 12,250 #12 Posted December 9, 2020 Should mention that Subaru's (and others) CVTs work essentially the same way but instead of pulleys they have two tapered drums interacting in a bath of highly engineered fluid (CVT = constant velocity transmission) 2 Share this post Link to post Share on other sites
DennisThornton 4,769 #13 Posted December 9, 2020 4 hours ago, Handy Don said: Should mention that Subaru's (and others) CVTs work essentially the same way but instead of pulleys they have two tapered drums interacting in a bath of highly engineered fluid (CVT = constant velocity transmission) Continuously variable transmission 4 1 Share this post Link to post Share on other sites
ebinmaine 67,704 #14 Posted December 9, 2020 7 hours ago, Handy Don said: others) CVTs 2 hours ago, DennisThornton said: Continuously variable transmission Trina's Honda Fit has one. Absolutely fascinating to hear and feel it run for gear jammer like me. Engine comes up to a certain RPM depending on multiple factors and just stays right there whilst you go beebopping up to speed. Zippy little sucker too. Share this post Link to post Share on other sites
slim67 2,735 #15 Posted December 9, 2020 9 hours ago, formariz said: Would this be it? It was on the engine. that would be a drive clutch 1 Share this post Link to post Share on other sites
wallfish 17,019 #16 Posted December 9, 2020 Also known as a torque converter. That's what is used on the snow plow bike. 3 Share this post Link to post Share on other sites
953 nut 55,337 #17 Posted December 9, 2020 10 hours ago, formariz said: It was on the engine. Holding out on us? 3 Share this post Link to post Share on other sites
slim67 2,735 #18 Posted December 9, 2020 13 hours ago, formariz said: Would this be it? It was on the engine. Is that a 1 inch straight shaft by 3 inch with 1/4 keyway? If so someone doing a big block conversion on a golf cart would be interested in that if your not going to use it. Golf cart engines have a short tapered shaft which makes using the OEM clutch a pain because an adapter is needed. Plus you have to usually cut off and re tap the pto shaft destroying an engine that could maybe reused for something else. That looks like a Comet but Salsbury is another manufacturer also. Share this post Link to post Share on other sites
Handy Don 12,250 #19 Posted December 9, 2020 8 hours ago, DennisThornton said: Continuously variable transmission Duh. thanks, Dennis! Share this post Link to post Share on other sites
DennisThornton 4,769 #20 Posted December 9, 2020 7 minutes ago, Handy Don said: Duh. thanks, Dennis! I'm having those moments more and more lately... Share this post Link to post Share on other sites
JoeM 7,874 #21 Posted December 9, 2020 Is that arrangement used on some side by sides too? Share this post Link to post Share on other sites
formariz 11,987 #22 Posted December 9, 2020 4 hours ago, 953 nut said: Holding out on us? Its been a few years forgot it was on it Share this post Link to post Share on other sites
formariz 11,987 #23 Posted December 9, 2020 1 hour ago, slim67 said: Is that a 1 inch straight shaft by 3 inch with 1/4 keyway? If so someone doing a big block conversion on a golf cart would be interested in that if your not going to use it. Golf cart engines have a short tapered shaft which makes using the OEM clutch a pain because an adapter is needed. Plus you have to usually cut off and re tap the pto shaft destroying an engine that could maybe reused for something else. That looks like a Comet but Salsbury is another manufacturer also. Yes it is. Unit is actually 4-1/2" but engine has a 1x3 shaft. Share this post Link to post Share on other sites
Achto 27,623 #24 Posted December 9, 2020 This clutch & torque converter system works quite well. Here is a little demo of how it works. 3 Share this post Link to post Share on other sites
slim67 2,735 #25 Posted December 9, 2020 1 hour ago, JoeM said: Is that arrangement used on some side by sides too? Polaris was first. I think a lot of others have too. Golf carts,utility vehicles, snow mobiles and 6 wheelers also use this system. It's probably on other stuff but I think of what. Share this post Link to post Share on other sites