On 1/3/2015 9:20 AM, Bob Engelhardt wrote:
I have a self-propelled leaf blower/vac. The wheels are driven by a
belt that goes down from the horizontal shaft of the engine, turns
horizontal to go under the deck, and turns vertical again to drive the
axle. All that turning is problematic and the belt keeps coming off.

This is a blower that I reconstructed from the parts of 2 scrapped ones.
Same model, so no fabrication involved, just bolting together. At
first I thought that I had gotten something oriented wrong, but I've
ruled that out (most parts only go one way and I have a parts diagram
that agrees).

Here is a picture of the underside. The arrow points to the spot on a
pulley where the belt "enters" it at an angle. Of course, the belt
wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it by
changing something. But this is the way that it came from the factory
and it should work. What am I missing?

Thanks,
Bob
My large mowers have 1/8" hard wire bolted to the chassis and over the
belt - keeping the belt between the loop of the wire on both sides.
As pressure on the belt (from motor or wheels) the belt tends to shorten
on one end and lengthen on the other for the start up. Belt jerks are
common. These loops are then more like 7 or a z where the bottom bolts
on and the vertical section goes over the height of the pulley and the
wire bends over the pulley. keeps the belt with some slack on the
pulley. And so on.

Martin