belt guide

[dav 2]

I put the new Simplicity belt on the snow blower and finished cleaning up the yard. But the belt keeps jumping off the crankshaft pulley. The pulley is not an original but is pretty darn close. I put it on with the allen screw out(away from the motor) as this made the belt appear to sit right in relation to the belt guides. But it does not look like it is in the right relationship with the two pulleys below it. To reverse the pulley will be to move the belt completely out of the guides. Can someone post a pic of the pulley and belt showing which way the pulley should be and what the guide should look like? I'm not certain that the guide is the right one. Thank you

[BLT 717]

Well I would say that the most important part is to get pullies aligned to keep belt from flipping off. After that make new belt guides. Their only function is to keep the belt very loosely around drive pulley when the belt is disengaged and keep the belt from turning machinery when when disengaged. When the belt guides are adjusted to 1/16 to 1/8" pulley clearance, the belt will want to both crawl up and down the at the same time. The belt should never slide to the drive pulley if guides are doing their job.

[Kent 435]

See this page: http://simpletractors.com/operation/snow_thrower/page_4.htm

[dav 2]

Compared the guide I have with one on a 3012. Mine appears to be just a little shorter, maybe a quarter of an inch. But I think now that the new pulley is a bit smaller diameter than the original. This makes the snowblower turn faster and throw snow further. However, the smaller pulley size means that the stock belt guides were too far away from the pulley. I hope the minor tweak I did this afternoon will compensate for that. Tonights 14" to 24" will give me plenty of chance to fine tune it tomorrow

[RayS 79]

The diameter of the pulley on the engine should be 4 1/2" . My manual also says that the center of the V on the pulley to the end of the crankshaft should be 3/4" to have the right relationship with the 2 pulleys below it.

[D-17_Dave 12]

dav, I think if you'll look at the pic Kent showed in the link, you'll see the guides are well away from the pulley and they hinge in such a manner as to keep the belt close to the pulley but they don't actually touch the belt while engaged. One thing to remember on belts is it's important to have the belt come on to the next pulley straight. However it can leave the pulley offset. What I mean by this is to aline the idler that is stationary so it makes the belt come onto the crank pulley straight. As I remember the idler has some adjustment for this. That will make the belt track onto the crank pulley while it motion. The pulley that engages the blower is groved so it will self aline, and there is enough distance to the driven pulley on the blower shaft to allow the engagement pulley to float and let the belt "find" the correct place on he driven pulley. I know this sounds a little long winded, I hope I've made sence. Just remember the belt must lineup to go onto the next pulley in the routing. It can come off the pulley crooked. Also , make sure the idlers are genuine simplicity. The ones on mine were not. They were off sised and made incorrectly for the application, it all worked perfectly when I replaced em with a simplicity belt and simplicity idlers.

[mark64 0]

I think a smaller pulley on the engine will make the blower run slower? Mark

[UCD 14]

The pulleys on an FTD should be a 4½' on the engine shaft and a 5" on the blower. This will give the correct auger speed as designed by the factory. A smaller pulley on the engine will give a slower auger speed and poor performance as will a larger pulley on the blower. A larger 5" pulley on the engine or smaller pulley on blower will give higher auger speeds and throw snow further but will take more hp in the heavy stuff. When useing a newer blower designed for the RBT's on a FDT the 7" pulley should be replaced with a 5" pulley to get good performance.

[dav 2]

Mark, you're right, the smaller pulley WILL slow down the blower. Not the first time I've had things backwards. Time to find the broken pulley (I seldom throw anything away) and match it up correctly. Still, the blower has enough power to compact the wet snow we had over the weekend into tubes of ice in the chute. Last years Appliance Paint job has worn off. Next storm I'll give a try to Pam.