Hayter Spirit 41 Rattle

[TimF]

My mower is running well but has developed a loud rattle when the forward drive is engaged which seems to be getting worse. There is also some loss of Drive power and some variation in Drive power too. It sounds as if the chain is striking the chain guard and the chain seems quite loose but this wouldn't seem to explain the loss of Drive power.
I've looked at some of the posts/replies and investigated the variator pulley. The two central discs seem to be moving freely on the central spline. However a couple of pieces of thin metal fell out from between them. There is one thin metal disc between the two central discs but I wonder if there are supposed to be 2 and whether the metal that fell out is part of one that has failed and whether this could be the cause of the rattle.
Is anyone able to help please?

[Mick]

Hi TimF, and welcome to TGMF.

I have seen the Spirit do this before, it was the shaft (pin / key) slipping in the left hand side end of the plastic roller.  Make sure you don't have too much side play in the roller or t will let that key jump out of the slot. They also have a habit of the roller end collapsing and breaking out.  I would check that first.

The variator pulleys do have those little this tin rings, and they do fall out in pieces.   They usually.  I would first check the roller, and if you're lucky enough that the variator still drive ok I wouldn't worry about changing it. They are quite pricey. 

[TimF]

Hi Mick and many thanks for such a quick reply.
There doesn't seem to be any side play in the roller or damage to either end of the roller.
I'm wondering if one or both of the drive belts is causing it - the tension seems ok but maybe there is some wear to their edges. They haven't been replaced for at least 8 years

[Mick]

I was more concentrating on the rattle you mentioned, to be honest the belts even if worn shouldn't cause it to rattle.  They can obviously run loose and slip when worn though.

Did you manage to find anything?

[TimF]

Hi Mick,
I'm still at a bit of a loss to understand what is going on. The main symptom is the rattling chain but there is some loss/intermittent power to the roller so wondered if the belts were slipping and causing the chain tension to vary causing the rattle.

[Mick]

Have you removed the chain cover to see what's happening with the chain?  it's only one bolt to remove the cover so might be worth a look..

[TimF]

I've taken the cover off and the chain seems quite loose, although not so loose that it would slip off the sprocket. The chain itself seems in good condition.
 I think I will have to put oil back and run the mower to see what is going on with the chain as I'm sure the rattle is caused by the chain against the guard

[TimF]

I convinced myself the problem was the belts and/or pulley so I replaced them all. Unfortunately the rattle and variable drive power are still present. However the torque on the roller is much better.
I can now only conclude that the problem is the chain - it's very loose so I am going to replace it.

[Mick]

The chains can get quite loose, and even more so if the roller bushes and shaft have wear in them.  Hopefully it is just the chain though.  For curiosity I would just drive it without the chain cover on for a bit and you'll see exactly what's going on there. 

[TimF]

Chain replaced - all is now running perfectly

[TimF]

Many thanks for your thoughts and help Mick