ksmith

Hi jesb No sorry I don't know what the exact colour is, I do know that the Majesty tanks and frames where powder coated by a firm in Manchester. I think you should ask the same question as a new topic, I'm sure that's lots of forum members will have the answer. Kevin.

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 )

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

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.

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.

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.

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

No the clutch arm is on top, here are some photo`s from the rebuild.

Please take a look at some photos of interest on the Yamaha forum. I originally wanted to put them on this forum but they ended up in the Yamaha section ?. Here`s one anyway.

Here is a photo of one of the engine bolts, they are all the same just different length`s, individually turned in Titanium, note the feed marks and the end centre. there are lots of talking points about this bike and I have lots of photos. Just ask.

I have never had the chance to compare my engine with another, it would be nice but very unlikely, here`s a photo of the engine number and frame number (the frame has since been glass blasted).

Yes this 250cc OW10 engine was from the 1973 cantilever bike, but it is worth pointing out that all other Yamaha Works Trials bikes ( what ever the model ) had there engines numbered OW10, they are all are very different, ( O= prototype W= works and the 10 denotes TY). note the clutch case and clutch cable on Mick Andrews OW10 cantilever bike below. About ten (250cc) engines were made for the cantilever bike but only a few have survived, at a glance they look like TY twinshock engine`s but none of the components are interchangeable they are one off`s. The barrel is the Majesty S type only used on the Majesty Works bike`s it is a TY barrel bored to 74 mm and re`sleeved with new port timing, the finished bore is 70 mm ID with a stroke of 63 mm. Please see the photos below. Many thanks to Mr Clay Seltzer (vintageworksbikes.com) and Mr Torsten Hallman (four times World MX Champion) for explaining the meaning of Yamaha works numbers.

The clutch cover is in one because the Works engine has no oil pump, the casings are sand cast in RZ5 Magnesium, take a look at these photos and note the straight cut primary gear with titanium nut and billet machined clutch basket, other titanium components include , the spring compression screws, clutch retaining nut, barrel studs, drain plug, all the small fastening`s and plate`s within the engine, the chain ring bolts and rear brake cam. Also the primary gear is on splines to the crank, and the crank in supported by 6306 C3 bearings (30mm ID- 72mm OD- 19mm W).

Here are a few photos that some of you may find interesting. I am sure that most of you know that in the early 1980s Majesty produced two works bikes fitted with works Yamaha 250cc, OW10 engines (from the 1973 cantilever bike), one for Mick Andrews and the other for John Hulme. the bike that Mick andrews rode is well documented but Johns bike is not, so for the first time in nearly thirty years here are photos of Johns bike. It is now up and running and ready to be restored after being stored in boxes inside my old Hen house all of that time (1988) the bike is in original condition apart from the brake lever, tyres, cables, and paint. I would just like to say a big Thank You to, 'Sam' Brownlee (Majesty`s team mechanic) who knows every nut bolt and washer on this bike, without his help this Topic would not have been possible.

Hello. I would like to hear from anyone who as any information about the Works Yamaha OW 10 engine. I would also like to share the information that I already know, I know that there are less than 10 in existence, the casings are Magnesium lots of the internal components are Titanium and the clutch lever is on top of the engine. Here are a few photos of my engine. Kind Regards.