Here are a few more photos, note the magnesium clutch boss, and that there are only five clutch plates. Enjoy.

Edited May 28, 201412 yr by ksmith

I do like that clutch cover...

Hi jonv8. Thank`s for your comments, it`s a shame that the clutch cover does not fit the standard TY engine, if it did a patten could be taken from it but the shape and hole centres are different.

That flywheel assembly seems to have a massive amount of lightening. Did you by any chance weigh it? The magnesium also looks to be in excellent condition. Remember to paint or lacquer it to keep it that way!

Just love the selector drum

Hi Mattylad. No, I never thought to weigh it, but I can tell you that the web thickness and all the diameters are greater than the standard TY.

And yes I do agree Woody, the selector is great, that and the clutch basket are my favourite components, Thanks.

Shouldn't the big holes in the crankshaft be covered with something for maximum pump effect?

One can still see the punch marks to keep them in place.

Shouldn't the big holes in the crankshaft be covered with something for maximum pump effect?

One can still see the punch marks to keep them in place.

Yes it must have had plugs in the balancing holes at some stage

Something odd: I've not seen crank balancing holes on the opposite side of the crank wheels to the big end pin on a trials bike before.

I'm thinking aloud about what might be the reason: We know this motor is currently 250cc. Maybe when the crank was made, it only had balancing holes in the pin side of the crank wheels, and it was balanced to suit a bigger diameter(heavier) piston than what is in it now. Then for some reason the motor was then converted to a smaller piston (the 250cc it is now), and to get the crank balance right, balancing holes had to be put in the non-pin side of the crank wheels

Shouldn't the big holes in the crankshaft be covered with something for maximum pump effect?

One can still see the punch marks to keep them in place.

Yes guys you are right, when the engine was new and fitted in the works Yamaha 0W10 bike the holes had nylon plugs fitted within them, what you have to bear in mind is by the time Yamaha donated the engines to Majesty five years had past by, the works barrels and pistons where just not practical for a small team like Majesty, the barrels where made from magnesium with paper thin chrome plated liners and the pistons where forged from some strange alloy to suit, both by this time genuinely unobtainable, this is why Majesty had to develop there 'S' Type barrel, it also enabled them to use standard TY pistons, it was at this point that the plugs where removed.

As with all small teams they had to chop change and alter what was available until they where happy, in a conversation that I had with John Hulme about the changes to the bike he summed it up very nicely, quote ( it just worked ) even thought it was made from bits.

And yes I agree with what you say feetupfun, but I am sorry to say that I just don`t know if it is right or not. All of the information that you see about this topic was very kindly told to me by Mick Andrews, Sam Brownlee and John Hulme. Sorry.

Edited June 7, 201412 yr by ksmith

the pattern of the holes in this IT250/YZ250 crankshaft advertised on eBay UK looks a lot like the pattern of holes in the works crankshaft shown above

I would be curious to know the stroke on both.

Guy

the pattern of the holes in this IT250/YZ250 crankshaft advertised on eBay UK looks a lot like the pattern of holes in the works crankshaft shown above

Thanks for the photo feetupfun, the crank is very similar in pattern apart from the primary gear which is key located.

I would be curious to know the stroke on both.

Guy

Hi guy53 I have been asked the stroke dimension of the works Majesty before, so I will measure it ASAP and let you know.

( It is 63 mm )

Edited June 13, 201412 yr by ksmith

I use to see a lot of crankshaft like those being shown, when I raced Yamaha engines in go-karts. We would drill or grind the holes in the crankshaft to lighen then and the fill the holes back in with nylon or aluminum. The reason was to get the engine to spin up faster. We would rebalance the whole assembly, chankshaft, rod, wrist pin,piston as a unit. This could be what and why it was done in the OW engine.

Thanks so much for the images and observations. They're fascinating, and add to the history of TYs and Majesty.

Did you get a colour match for the Majesty yellow before you had the frame blasted? I'd like to have an authentic colour reference as I've just obtained a TY175 with what I believe to be a Majesty frame. Like yours it has yellow under silver, though I haven't yet exposed enough to do a colour match. Any comments gratefully received...