In the UK a fastener threaded all the way was referred to as a "Set Scew" or 'Machine Screw" , Bolts always had a shank and a threaded section I believe to reduce the stress concentration around the head when subject to high torque and high tension loads.
Most 250's are almost the same, all can be de-tuned. Question therefore you may like to think about is which make has good dealer support in your area and if you go to club trials in your area you may find a strong local brand following - there is usually a good reason for that.
The Falcons are very good and Robin and team are most helpful. Bend a Betor and it is in the bin, Falcon back in a few days rebuilt. They would be top of my list.
Sounds like an air leak and ours runs best with an Amal carb. The Mikuni always worked well at one end or other of throttle opening. Added advantage of Amal is you can then run in British bike events !!
Yes, there is a kit on the market and very good it is, have it fitted on my sons TY. It is the chap who makes the 220 Yamaha conversions that Mick Andrews rode and tested in CDB magazine.
Did not know about it - have a road going Ariel, that would like a trip over the Severn bridge. One question I always ask myself as an unskilled club rider, will I make it round or are the sections aimed just at the top few. This is the sort of information that saves a 200 mile wasted journey.
Not that straight forward - Is it a Shirty Yamaha Majesty or is it one of the new frame Majesty. Use same hub but different offset also some use a flat sprocket and others the TY dished sprocket.
250 'Majesty/ frames
in Yamaha
Posted
Jonv8 does conversion of std frame as per originals.