[Motivator]

Hi all have a bit of a problem with this old fav of mine .
 The blades will not rotate and there is no self drive , There seems to
 be a lot of slack in the chain . Am  right in thinking it could sheered its
 gears .

[Gwiz]

I don't quite know the set up on the more modern ones, but they used to have a centifugal clutch next to the engine, this engaged the primary drive chain to the blades, and a pulley on the other side of the blades, took the drive via a v belt, to the rear roller.
With the side casing removed, start the mower, and see if the chain turns when you throttle up. if it doesn't, either the top cog has become loose/ or it may have worn the drive shaft, or there is a fault in the centrifugal clutch.
keep me posted!

[Motivator]

Thanks fella the top cog does seem slack . There is no chain drive under power .

[Gwiz]

yep, seems to me that it may have become a tad loose. it does have a sqaure drive centre, which can wear if the nut becomes loose. don't worry too much if it has worn out, spares are very cheap and plentiful!, I might even have the bits for one stashed away in a dark and dingy corner of the equipment shed someplace (unless aunt sally has put it away somewhere safe)
let me know how you get on.

[Motivator]

Thanks Graham will take a look tomorrow see it will tighten up .
 Will let you know.

[Motivator]

Well nut is not loose will have to look a bit closer .

[Gwiz]

I've found an entire mower, should you need bits.

[Motivator]

Thanks Graham will take a look tonight and some pics .

[Motivator]

All very stange there seems to be a lot of slack on the chain and a lot
 of movement in the shaft .


http://s70.photobucket.com/albums/i90/peterfroud/?action=view&current=22-05-08_1932.jpg

http://s70.photobucket.com/albums/i90/peterfroud/?action=view&current=22-05-08_1931.jpg

[Gwiz]

okey dokey, where the small cog is, the shaft goes through the side plate. on the othere side, it passes through a bronze bearing, which will (if not cleaned and lubricated reguarly) wear out (goes oval). you then get a lot of "play" up and down, where there should be none at all.
likewise, the rotating blades should have no up and down movement whatsoever, but often a lack of grease and oil will destroy these bearings in double quick time as well.
there is a small bronze bearing insert within the bell housing of the clutch. this will wear too, but nowhere near as much as the others I have mentioned.
check these out. You can adjust the chain on the plastic covered slider under your finger in the first photo.
keep me posted, I haven't thrown that old mower away yet!

[Motivator]

Will be looking later Graham thanks for the advice . Dont throw away
the mower just yet.

[Gwiz]

Thanks for the pm.
can you turn the blades by hand? if so, then the problem will be in the clutch.
if you are having problems with the self drive, the drive belt is adjustable.
not only does it have a screw thread adjuster on the cable, but the front pulley comes in two half's, with spacing shims between them. when the belt gets a little , shall we say, worn, you can pop out a spacer or two to get the belt a little tighter on the pulleys.
as for the clutch, its centrifugal, and consists of two clutch shoes (like brakes) and a couple of springs.
sometimes the springs get rusted and seize, and sometimes the clutch shoes covering just wears away completely so that there is no covering at all! that just leaves you with a metal to metal surface that isn't very efficient.

[Motivator]

Hi Graham yes the blades turn by hand . Just a quick question where
 is the clutch located exactly is the clutch located . I see what your saying
 as there is no drive atall to the blades when your power up the throttle.
 Will have to look at adjusting the clutch .

 Will be in touch.

[Gwiz]

the clutch is located in a bell housing between the engine and the side plate (asuming that yours has an engine and isn't one of the electric models)
to get to the clutch to have a look at it, you can just undo the four 13mm bolts that hold the engine on and slide it out of the way. you will see the clutch shoes on the plate that comes away with the engine.

[dorimower]

Quick safety note....never ever attempt to run an engine fitted with centrifugal clutch with the engine off the machine..ie; with shoes exposed.
It is so tempting to do....but at the very least it destroys the return springs....and the shoes could fly off and cause serious injury, etc........

Check it all out whilst static, do the repairs....then re assemble engine to chassis so that the shoes are correctly and safely housed within their drum before any attempt to run engine.

"Dori."