timdog

As above, left side of headstock. It may of been painted over several times so it’s worth stripping paint off the area to check

C15T 101-301 were 1959 trials engines. Seems unusual a trial engine ended up as road bike, but who knows what has been done over the years. Do you have the frame number. It would be great if you could locate any paperwork or registration documents. Restoration depends on how much you can do yourself, how much time and interest you have, how much money you are prepared to spend and whether to restore as road bike or use engine as donor for a brand new pre65 trials bike.

Also don’t tighten the gap so it nips the feeler gauge, just touching so it will slide in/out ok, Too small as gap is as bad or worse

Piston rises to top of stroke on compression and exhaust stroke, with spark plug out you can feel the slight pressure on compression by putting thumb over the hole, then align the marks when you know it’s the compression stroke. haven’t adjusted mine so I’m not sure of the timing marks used on beta flywheel. Some decent videos on YouTube of how to do it . Has to be compression as that’s when the intake and exhaust valves are shut.

Did you set them while on top dead centre ensuring it was on the compression stroke.. must be on compression stroke

I bought one from eBay “Ryde small motorcycle cover.” Only £8, covered trials bike well and survived motorway journey from Kent to Northumberland in the rain. Not completely waterproof but kept all the road muck off

Also Villiers services are handy site for engine spares if needed

Shows up, barely, on this one

I got a set of tank stickers from vmccshop.net

Jitsie omnia pants, still stretchy and comfy but not skin tight spray on, I bought a size up from usual and they are loose enough

Try Richard Allen trials spares on Facebook

Everything Jonboy said is true, very friendly sport, lots of people take it up around this age. Details of local clubs are on acu.org in members area. You can join a club and get your licence online. One way to get a bit of practice would be to go to a trial and learn how to observe, then you can observe a few trials with your bike, have a bit of a ride round and practice off road while there. When ready find out which are the easier venues near you and enter, you can always skip anything to really don’t like until confidence builds. Best practice will be taking part, beauty of trials is we all fall off. People will just give you help and advice.

Agree re front sprocket as above, Bosi exhaust and it will sound superb

I’ve had 2 beta 4ts and never had any problems over and above the normal servicing. Only niggle I find is they don’t like stalling, so if it does when hot and won’t start after 2 kicks, pull the red hot start lever out to start it. Personal preference but I find the fast standard throttle too quick(maybe perfect for you) Amal 80/200 throttle makes big difference just put the nipple in the “spare” hole on carb end, it’s obvious when you look and it fits perfect. Other than that I love them, very different to 2 stroke

Changed my c15 to historic vehicle. No need for insurance as vehicle is SORN

If you can get/borrow a volt meter check the voltage of each of the batteries after charging. A charged 12v battery should read about 12.7v if it shows 12v it’s actually classed as discharged and that means dodgy battery. However sounds like your Oset charger itself may be dodgy, we went through two when had Osets over 4 years. As above charge each battery separately and check they are ok then replace charger.

Other brands are available!!

Jet is too except in certain area such as teeside Yorkshire the Humber and Scotland

Meant to say I put it in fuel for 2T and 4T bikes too. No issues if a bike stands unused either.

Haven’t had any issues with Fantic tank. I use ethanol shield fuel stabiliser, originally for small chainsaw engines it’s supposed to prolong the shelf life of petrol and prevent the corrosive effect of ethanol, stops it absorbing water. It’s relatively cheap, only needs tiny amount for 5l of petrol. I can leave petrol in chainsaw for months on end as it doesn’t get used much and it still starts and runs fine.

As above, buy copy of the book, separate one for engine, it’s worth it’s weight in engine oil. Explains everything including improvements. Having had problems with clutch slipping on starting from cold I run chaincase dry. The Oil is only for the chain. As bike doesn’t do road work at constant higher revs I just use chain lube on primary chain, sprayed onto it via breather pipe hole. Works for me.

Beta 4t with one tooth less on front sprocket. Amal 80/200 throttle slows throttle response, softens it noticeabley. Beauty of this throttle is cable just swaps onto the spare hole on throttle cam and tension then perfect (it’s easy to see when look at one)Doesn’t need anything else, bike is very forgiving and pulls so well in any gear. I haven’t rode a montesa 260 but friends with them say my beta is “softer”. Owned two and never had any issues or had to adjust valve clearance

If concerned check engine and vin number against v5 and that sellers details match v5. As above, hpi check Are there 2 sets of keys

You mention 4 stroke, 4 stroke beta is VERY soft in power delivery. Very forgiving and easy to ride and maintain. Certainly can’t fault the montesa for build quality, it’s all personal preference and not everyone likes 4t but thumbs up for the beta, particularly if you put slow action throttle on.

I can recommend soft brake linings used by Villiers services. Simple to book relining on the website just send old shoes in