Challenge Xtreme XSZ40

[Shaffick]

Hi all.

I decided to put my Challenge Xtreme XSZ40 self propelled mower back together again after I stripped it down last year. My question is could somebody tell me where or how the tension spring that clips onto a little clamp on the mower body connects onto the gearbox housing?. I should've taken a photo prior to strip down. Thanks.

 

[Burnerman]

The purpose of the spring is to pull the gearbox back against the power of the transmission belt.
There should be a lug or a hole on the gearbox somewhere, look for a small notch that has been caused by wear. Sometimes the spring pulls horizontal, sometimes vertical which I appreciate isn’t much help!
All I can really say is that the lug will likely to be at the back of the gearbox.
John

 

[Shaffick]

Thanks John. Could this be the reason why my self propelled wheels weren't propelling very well? Lol.

 

[Burnerman]

For sure, if the belt was slack then it wouldn't be transmitting the drive......also it may tend to slip off. Also check the belt itself - it should be a V section - and the plastic gearbox pulley. If it's edges have been worn sharp then it needs replacing.
John

 

[Shaffick]

Thanks John. In regards to changing the new belt, do you have to loosen the 3 engine retaining bolts to get a little play in order to fit the belt?

 

[Burnerman]

No, not at all.....just remove any plastic shrouds, hook the belt onto the gearbox pulley and then wind it onto the crank pulley, turning the crank as you go.
Take the spark plug cap off though, just in case it fires!
John

 

[Shaffick]

Thanks again John. Much appreciated.

 

[Shaffick]

Hi again John.

I fitted that spring today but the self propelled movement isn't very good. I think that the belt is worn. Is there a possibility that the belt has stretched?. Thanks.

 

[Burnerman]

As there isn’t much force on these belts, stretching is unlikely - more common is the belt has partially shredded or the axle pulley has worn.....its only plastic and can wear quite heavily.
Of course the belt issue has to be ruled out before you go any further as axle repairs aren’t possible.
You may have noticed a lever on the top of the gearbox that is operated by the handlebar cable so check that the cable isn’t too slack.
I’m assuming the correct drive belt has been fitted, and it isn’t a replacement!
John

 

[Shaffick]

Thanks for your reply John.
The belt is the original one. The pulley looks in serviceable condition. The cable going to the lever has the right amount of tension on it and definitely operates the lever. I stripped the gearbox and lubricated all the mechanisms. With the mower raised and the engine running and the self propelled handle applied, the rear wheels do spin but seemed underpowered once lowered back to the ground. I might just give up lol!

 

[Burnerman]

The only thing you can really do is to get the belt tight enough, just to ensure it's not slipping.
If you are happy with that and the drive is spasmodic once on the ground - perhaps you can stop the wheels by gently pulling the machine backwards when it is trying to drive - then its a replacement axle required....ebay may come to the rescue but a new one isn't cost effective, unfortunately.
Nothing to stop you popping the back wheels off and checking the drive and condition of the smaller gear pinion (if you can lift it up and down within its bushing its game over) and cleaning out the crap on both of the gear wheels teeth.
John

 

[Shaffick]

I've cleaned the gears and teeth in the wheels. I feel that the belt is at fault. It doesn't seem as tight as it should be. A new axle isn't cost effective as you said. Thanks again for your advice John.

 

[Burnerman]

No worries at all....maybe you could cobble up another spring just to increase the tension a bit?
John

 

[Shaffick]

Good thinking batman. I'll give that a go. Thanks again John.

 

[Shaffick]

Just one last question John, this engine SV150/RV150 seems to pop a lot when running. I have had 2 sovereign mowers with the same engine do the same. Is this normal for these engines?. They seem to run fine?
Cheers.