[balmoralboy]

I have had a certain amount of trouble with my Husqvarna 970 rider, which i think relates to poor service from the dealer the last owner took it to.

The deck on this unit is belt driven through an intermediate jackshaft. I usually refer to them as the back (meaning the belt that runs from the main engine shaft to the jackshaft) and the front (meaning the belt that runs from the jackshaft to the deck) Just for reference, there is a second belt running from the engine main shaft to the transmission.

<img SRC=http://www.balmoralmotel.ca/350/Husq0005.jpg>

In the picture the upper belt is the transmission drive belt, the silver wheel with the cable on it is part of the steering system, and the lower belt is the belt driving the jackshaft. The piece of bent steel rod is a guard over the lower belt.

I have replaced a number of parts including idlers and belts on the front deck and have been running trouble-free for about 6 hours.

Suddenly, the machine has begun throwing the rear deck drive belt which runs between the engine and the jackshaft. the LOWER belt which in the picture is shown running upward to the left. The first time it came off I had been running in reverse for 25 or 30 feet. Since then it comes off every time I mow in and out of a hollow or go up a short incline. This time it was on a flat section and the belt is badly torn up.

Logically, one would think that the jackshaft or the engine shaft must be flexing and causing the belt to be thrown. However, they are extremely rigid, and that isn't the cause.

So, What's Up with this? and how do I cure it?

 

[guest2]

Not sure what's causing it but on my craftsman GT when the belt came off twice it was due to a bad pulley. Once the belt gets thrown off a few times it's pretty much trash even it looks OK. Did you check the pulleys to be sure they're not bent or seperating? Only other thing I can think of would be the belt itself,are you sure it's the correct size?

 

[Neil_nassau]

Check the grooves of the drive pulleys closely for any piece of a stick or debris that prevents belt from running through smoothly.

Is there an idler of any kind in the drive from engine to intermediate (or mule drive ) pulley. Is it lined up and floating freely through its entire range if its spring loaded or tensioned properly if its bolted.

Are your blades dull causing excess belly in the drive belt. Remeber a belt is "pushed" on one side and "pulled" on the other side of a drive causing slack in one and tension on the other.

Was the belt guard moved out of postion from the first incident..........guard s like this usually have to be VERY close to belt/pulley.

Good luck.

 

[balmoralboy]

Thanks, Neil

Originally posted by Neil_nassau
Check the grooves of the drive pulleys closely for any piece of a stick or debris that prevents belt from running through smoothly.

Is there an idler of any kind in the drive from engine to intermediate (or mule drive ) pulley. Is it lined up and floating freely through its entire range if its spring loaded or tensioned properly if its bolted.

Are your blades dull causing excess belly in the drive belt. Remeber a belt is "pushed" on one side and "pulled" on the other side of a drive causing slack in one and tension on the other.

Was the belt guard moved out of postion from the first incident..........guard s like this usually have to be VERY close to belt/pulley.

Good luck.

Thanks, Neil

The idler between the engine and jackshaft is a steel smooth-faced idler controlled by a cable. This is actuated by the deck lowering lever so that power is transmitted to the deck when the deck is down.

Pulleys are smooth and clean.

Guard is in proper alignment.

I have new blades I'll put on, that may be part of it. Also, from another thread I've picked up that I should be cutting back the engine speed before engaging the deck. Hopefully, between the two that'll do it!

Thanks again

 

[jd8567985]

Try having the engine speed down to idle when turning on the blades. Turning on the blades at a high engine speed may stretch the belts. That may not be why as I am only 12 years old.