I bought the bike in question last April from Bavins of Diss.
It is a Majesty replica and he had done all the frame mods, the engine craddle has been moved upwards, the steering angle altered and the rear shocks angled.
I initially found the engine very flat and I was struggling on climbs, on short climbs it was like the power was coming in at the wrong time instead of making your speed first the power was coming in when I would usally be wanting to back off and find grip.
I looked through this site and there was alot of advice on lightening the fly wheel.
I bought a spare fly wheel and had the weight skimmed by approx half of the original, and this did make a difference, I have never tried it without a weight.
I also noticed that on uphill sections the front wheel was way too light.
I measured the wheel base and it was approx 50" so I bought swing arm extensions and had these welded in.
This made the bike much better on uphill sections.
I contacted Craig from the Majesty site and he said that 52" is about what I should be aiming for.
I do have TY Mono forks to try once I find a Mono front wheel and yokes.
At a trial I let a guy with a Majesty 175 have a go on it and he said that the gearing needed changing and the damping from the rear shocks was poor.
I changed the gearing and bought Rock Shock rear shocks and Magical front spring from Craig.
All these things have improved the bike and it does turn and handle very well it is just that I thought that the 320 mod might be the ultimate mod for the engine
I had a go on a TY175 and that did rev quicker than my 250 but at 6ft 2" and 15 stone I wonder whether it may be a bit small for me.
I have also spent a fair amount on the bike so I would like to stick with it.