I have a Mountfield mower. The blades dont spin as they should, I can see the belt underneath has come loose or broken.

Any ideas if its something I could try to repair myself ? Any good websites with info about how to do this ? Funds are limited and I would need to arrange a trailer etc to get it somewhere to be repaired.

Can you turn it on its side and post a photo? Spares will be available from a Mountfield dealer or good garden equipment dealer/repairer and fitting will be easy-peasy.

Have you had a look on YouTube? When my ride on stopped working I found some great service vids on there made by people who clearly have far too much time on their hands! Mine wasn’t a Mountfield though

I was not sure about turning it on its side. Worried about oil or fuel getting somewhere it shouldn’t be. Is it an issue ?

On my Countax there was a lever underneath that moved the deck backwards to tension the belt that went from the engine to the deck – no adjustment, it was either tensioned or not and was there to make removing the deck easier.
It occasionally undid itself so the drive belt looked loose. Check to see if you’ve got one similar and that it’s in the right position.

Basically a belt either works or is broken – you can easily see if it’s the latter.

Work on these is very DIYable (especially belts) but youo just need to cope with the size of the machine as they can weigh more than you think. I have an engine hoist that I used to lift the front of the mower into the air so I have better access.

Edit: chances are you’ll have two belts:
1) from under the engine to the deck – this powers the deck
2) the deck belt which takes the drive from the deck pulley that ^ is connected to and turns the blades. If this has broken nothing will turn, but there will also be a tensioner pulley on the deck that’s spring loaded and maintains the correct deck belt tension. If the spring has gone the belt will be too slack so lack of drive.
You could also have knackered deck pulley bearings which could also give poor cutting.

Our Countax is a bit heavy for turning on its side and stuff!

Don’t know where you are but Stockbridge Garden Machinery are very good if you are anywhere near there… They will come to you, too.

Thanks for the replies.
Its just about possible to lift it onto its side but wont that stuff the engine ? One website recommended draining all the oil and fuel first ?? Seems a bit much.
I’m down Hampshire way. I’d rather not spend too much, just glad it failed on the last few feet so I have a week or two before the grass grows enough to tickle where it shouldn’t
I’ll have another look on the weekend. Determined to fix it myself, cant be that tricky.

DO NOT TURN IT ON ITS SIDE. You’ll probably get it wrong, and it won’t do it any good whatsoever. Stuff that will possibly leak, in no particular order: oil, battery acid, petrol, fermenting rain water, all the grass clippings that settled internally, and a bit of wee from you when it invariably goes wrong and you get crushed underneath.

Belt replacement will be a bit of a faff, but almost certainly doable with the mower in a normal position.

Have a look at the deck – you’ll probably need to undo a couple of bolts to drop it down into a service position, but ultimately it shouldn’t be too hard to get the belt off. Chances are it’ll be in a slightly weird serpentine fashion which means it doesn’t have anything “inside” it.

Can give you Stockbridge Garden Machinery’s mobile number if it helps… Nice chap and good service and prices.

Not related to him – just a satisfied customer!

So..
Finally got some time to take another look.
The belt had only come off all the pulleys, no sign of damage, belt looks fine. Refitted it, now the mower stalls when you engage the blades and they don’t turn. You can pull it round by hand, drive pulley feels a little stiff but turns Ok.

About to take the belt off and see if the drive pulley spins when engaged.

Any ideas ?

Probably one of the blade bearings has seized, which often causes the belt to get thrown off.

Take the belt back off, and try spinning each blade. Depending on the blade brake setup, you may need to lever the brake off (usually a pad that rubs on the edge of the blade pulley, if it’s a direct blade brake type). If the blade doesn’t spin freely, then that’s your problem. Also check for play that would indicate one of the bearings has collapsed.

If the bearings have failed, it’s usually easier and often just as cheap to just get a complete bearing housing assembly, as they’re a pain to dismantle, typically use odd ball size bearings. A new housing you just swap the pulley/blade and off you go again.

There are plenty places online that supply parts, but it usually means finding a part no, however just google for the model number (sticker under the seat normally). Mountfield are just rebranded Murray mowers IIRC, so parts are relatively cheap.

Its the drive pulley. It doesn’t move when engaged. When I turn it by hand it feels very stiff, squeaks too.
Its odd as when the belt first came off it wasn’t stalling, just no blades spinning and you could hear the drive pulley spinning. As if the belt had come loose or snapped but now its stalling ?

Sounds about normal.
It depends how the bearing has failed, as quite often it’s the momentum of everything spinning then one bit suddenly stopping, or at least reaching the point things slacken off to the point a bit extra load will throw the belt of.

With the belt back on, the extra load of a seized pulley while trying to get everything spinning will just stall the engine.

Actually, what do you mean by drive pulley? The one attached to the engine?

Yep, straight from underneath the engine. Pondering taking it apart to see what’s going on. There’s no play at all

When I try to undo the nut holding the drive pulley on, the pulley stays still and the bit above spins and in turn spins the belt driving the rear wheels. So I can’t loosen it ?

The drive pulley is connected to the engine when it’s engaged, so that’s fine. The squeaking will be the brake, as if it’s a clutch pulley, the brake is part of the pulley/clutch assembly.

Have you checked the blades and tensioner/guide pulleys spin freely with the belt of?

Yes they are fine. With the belt taken of it still stalls the engine when you engage it

Internals have probably fallen apart then.

You’ll need to somehow lock up the engine to remove the bolt as it screws into the end of the crankshaft, or find someone with an impact gun to rattle it off.
Taking the top cover of the engine will let you get access to the flywheel, but try and avoid using the cooling fins for locking it, as they are fairly brittle.

Right….

Engine cover off, nut undone and pulley assembly now sat on my lap.

Excuse my ignorance but I appear to have the pulley and above that is a disk which moves up and down, its being pushed against two parts which appear to be like brake pads. If I push this disk down the pulley spins freely. Is this a clutch or sutin ?

There is a lead which goes into this assembly, Would I be right in thinking the mechanism to push the disk to allow the pulley to spin is probably what’s not working ?

Took is apart as much as was possible, re-greased and cleaned everything and its working !!!!!!

So chuffed, god knows why it has seized but running fine now.

Thanks for all the advice..

Without pics or a diagram, it’s hard to say.

However the pulley will normally be held spring loaded against a static braking surface, and then when engaged, it’ll be pulled away from the static surface and against a moving surface attached to the crankshaft. There are quite a few designs, but it’s been several years since I’ve had one apart.