lsv

Could try a larger bore master cylinder - maybe off a road/trail bike model. That will make you squeeze the lever a bit harder to lock the brake...........

https://www.ebay.co.uk/itm/113158712359?mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338365712&toolid=20006&customid=EB266447402&amdata=enc%3A1RDMnJ-6DTeaZJOW2witnkA95&_trkparms=ispr%3D1

Got a complete set of spokes if needed................

Whilst the leg appears similar the bracket is a lot different TBH. I know, I have both..................

https://jbanyeres.com/product/caballete-aluminio-mitani-para-honda-rtl-250s-modelos-anos-88-89-13/

That's as maybe, but I wouldn't think Honda/Montesa would spec full compliment if they didn't think it was necessary. Full compliment have a greater load rating I believe............

It is VERY important to also check/replace the two more bearings that are in the swinging arm, these,if neglected can result in a very expensive repair....... Whilst agreeing with the above statement I would be wary of May be cheapest but they aren't the correct needle rollers in their kit - should be full compliment type..............

It is indeed a temperature related problem and I am glad you've now read the article properly. Whilst you may well get away with using AVGAS on a high revving hard working engine just be warned that you may well have the problems mentioned if used in a trials engine that is just pottering about at low revs - I know I did. As you say, safety reasons due the problem of using Ethanol as a substitute to prevent pre-ignition etc. But one of the problems IMHO is that it is a misnomer to call it LL when in fact it has a lot more TEL than the leaded fuel we used to be able to buy at the pumps. I believe the LL is just to try and appease the green lobby.....

https://resources.savvyaviation.com/wp-content/uploads/articles_aopa/AOPA_2020-07_why-valves-stick.pdf

Nothing to do with that, you will have valve sticking issues - I know this from experience............ Have a read.. https://resources.savvyaviation.com/wp-content/uploads/articles_aopa/AOPA_2020-07_why-valves-stick.pdf

Do not use neat 100LL AVGAS, you will have problems...........................

Hooray, for once a correct and sensible answer on here! Take note especially of the last sentence.

Usually 1.5mm pitch for both. Check yours with pitch gauge to be sure. (or use a standard M10 bolt to check against as they are 1.5mm pitch)

I suggest you check thread dia to see if it is 14 or 16mm then just do a search on evilbay for Honda petrol tap (loads on there) find the one that is right size etc see what model(s) it fits and buy a genuine Honda one rather than the chinese **** that proliferates on there! 🙂

Could use a honda tap - probably same thread.