I have a Cotton 250cc Trials bike 1966 and the engine is currently undergoing a rebuild. It was a long time ago the Villiers 250cc 37A engine came out, but I remember there was a definite problem with removing the rear engine fixing bolt. So when it comes to re-installing, what is going to be the best way to get the engine in and feed the 65mm rear securing bolt into place without taking off an outer casing? Can it be done?

Is there a special method, such as a hole in the casing to feed the bolt through or has the right hand cover got to come off before putting the engine back in place? 

Can anyone advise on best course of action as I would rather get engine back in all together.

There is no problem at all if the correct stud is used, it fits through the hole under the clutch arm through the frame tabs and engine mount. This has a fine thread at each end (cycle thread 26tpi) just fit a plain washer under each nut it will not come undone. Good to use one for the lower mount as well, Villiers Services should have them or they will point you in the right direction.

Also a good idea to cut a shallow slot to suit a screwdriver tip at one end so that the stud can be held or turned when assembling.

These are what you need https://www.ebay.co.uk/itm/271778047353 I normally get them from the show at Telford which was last week or Stafford in April.

Like the bike.

Edited February 24, 20197 yr by trialsrfun

Thanks ever so much...spoke to Villiers Services and issue in hand; great idea with the screwdriver slot. Cheers Steve