tried

Thanks for your help. I have now sorted the problem.

I will further investigate. The spindle looks Worn ! Cheers

So I guess that the pinch bolt will remove the play once tightened? Cheers

My son's beta Evo factory 2019 has got tech forks. Should there be two spindle wheel spacers. I have one on the caliper side and no spacer on the right hand side. I've noticed a little play on this side. Can somebody help?

In my experience trials in the 70s, 80s and 90s (my era when Britain produced many world class riders) there were over 150 riders entered every weekend, full of families. Trials these days are full of solo's with the odd Father/mother and Son/daughter team. There is no soul in the sport. Some Youth riders have support, but many talented riders don't . We've been there! If you want world class trials riders we must find ways of encouraging youths to continue with the sport and not venture into mx/enduro, football etc. We now compete in mx where entries are full and competition is very hard, but you get a sense of a big family! I've not had that in trials for years! You never know it might bring some money into the sport !!!

Hello, yes it's a mystery! I've been told that ithe in the early 80s, Honda were starting to get involved with montesa , hence , the H. I now know that the bike is a 349 frame with a 349 engine. Thank you for your help

There's the number

A better picture of the number. 51H ? 0221.

I forgot to mention , there is no number near front engine mount.

Hello, thank you for your help. I brought the bike thinking it was a 349 frame with a 348 engine. I guess it is a complete 349. My wife has confirmed the engine number as being 51 H 00221 . It is a sidecar outfit! It was running spot on, and then started seriously back firing. I think we've traced the problem to being a worn keyway ignition side. I've got a couple of ideas how to fix it, but fear it will need a new crankshaft. Do you know where I can get a crankshaft from , also, anybody to fit it as i don'tI have the skills/tools to do the job. A picture of the beast. Thanks

Hello, thanks for your quick reply. You can just about see the whole number. Thanks

Hello, can anybody help? I have a montesa engine number of 51H00221 . I've looked at engine and the serial numbers and the 348 should start with 51M. Im Confused! Any help appreciated as I need engine parts, thanks.

Yes, brand new plug, which oiled up quickly.

Thankyou for everybody's help. I measured the carburettor and it's a 28mm Mikuni. So i dn't think its that. Going to to address tha timming, points and condensor, also the leak down test next. Cheers