woody

Yes, thank you to the Congleton club for putting on what was a very enjoyable event. Proof enough that it's still possible to have a decent days trialling on good testing sections using a cheap and unmodified twinshock The balance of the sections seemed about right on the hard route, three or four difficult testers, a few tricky sections out of the streams onto muddy banks and the rest relatively straightforward but easily capable of taking marks if riders were careless. What was particularly nice was the chance to get the motor singing in 2nd and 3rd gear for the muddly climbs of sections 7 and 16. Section 16 - great section, brilliant, just like they used to be. No cobwebs left in the engine after that one... Sections like this seem to have disappeared over the years in classic trials with almost everything done in bottom gear now.. Well done also to Gerry Minshall, Peter Salt and Alan Wright for putting in the effort and trying to get a new twinshock series off the ground. This event has got the series off to a good start and will hopefully encourage riders to have a go and support other events in the series. Also had the opportunity to try some Bultacos at the trial, the orange Motak Sherpa and a couple of Spanish Sherpas. Thoughts are on the Bultaco forum.

Aren't they a bit small to sleeve something into? I think forks from a Triumph 3TA are what people use as they are a bigger diameter? Others will know for sure

Yes, Bultacos use 6205 C3 for the mains.

Mikunis in general do it, probably every Mikuni I've ever had has done it, whether an old 70s Mikuni off some Jap road bike (which yours looks like) or a brand new one - regardless of the overflow pipes being long, short or not fitted. Even if they don't flood when the bike is upright, they generally do if you lay the bike down at sections if you've no side stand, without turning the fuel off. They're a pain in the a***. The usual checks are as mentioned above, float level, float valve sitting correctly and not obstructed with something which prevents it shutting off fully when the float lifts. It would pay you to renew the float needle and needle housing - make sure you by a float needle with the rubber tip. You should be able to get them from Allens if yoou can given them any model numbers off the carb - or just email them a picture of the needle and housing. There are many variants of Mikuni.

The tensioner spring does use a roll pin to locate it as original fitment. The brake pedal assembly is nigh on impossible to fit or remove with the engine in. To have a fighting chance you have to fit the bushes after you have located the shaft - or remove the bushes before trying to remove the shaft. Without the bushes, you can get more angle on the shaft when waggling it around. The problem is usually the brake pedal as it invariably gets stuck somewhere. What I've done on mine is cut a piece off the end of the shaft on the clutch side so that there is more clearance when trying to juggle it out

Chips Quarry - great place, great venue. Some horrible sections in there, especially in he Colmore, and especially when covered in ice or snow. Picture below of a young Woody, majestically floating though a Chips section on OWP 4P, my 325 Sherpa M159. Taken at a Stratford club trial in '76 or '77. Had to sell it to buy a car not long after this was taken. About 10 years or so ago, I was selling some parts and a bloke arranged to stop by on his way home to buy something. He said he had just bought a Bultaco in pieces which was in the back of his tipper truck and could I tell him what it was. Easy enough to tell him it was an M159 model but then I saw the number plate - OWP 4P... My old bike. Couldn't believe it. I showed him the picture below and another few of the bike when it was nearly new. It inspired him to restore it. Unfortunately in the trial at Chips it broke and I had to relieve my brother of his Ossa (his first trial) and finish on that... One of the Ossa ripping it up the big hill climb in Chips Happy days, shame it's gone as a venue.

No idea about your stators but I used Bradford Ignition years ago, before they went to Spain (they're back now) They repaired two Ossa Motoplat stators which have worked fine since.

You don't need a stop light or reflector for MOT You don't need a speedo for MOT You can use a bulb horn due to the age of the bike - assuming it is Pre-73

Probably 15 - 20 is ideal. Not too far for the slower bikes and gives the field a chance to spread out a bit and reduce the chances of queues If that reduces options for the number of groups, if I was plotting it, I'd just ensure the better groups like Weston Wood and others with the big climbs and cambers etc. are in. The last group last year was a bit too tight and nadgery with a lot of leaning on trees and a bit of stop/hop in evidence. Getting some gas on up those slippery climbs, roots and rocks like Weston Wood is where it's at. There've been some good sections in there the last couple of years - oh yes, and as much mud as you can find...

Re: Magical fork springs. Magical don't do damper rods, only springs, spacers and fork caps. The replacement damper rods for Yamaha twinshocks are from Craig Mawlam who runs Yamaha-Majesty.com. He sold Magical products as well but the damper rods are his, not Magical.

I ended up using a standard road cam All I can remember about the sports cam and the high compression piston, it ran very hot. I can't remember how it actually performed but I went back to normal cam and low compression piston and ran it like that until I sold it.

My memory is not so bad then... My name is Dave Wood but your dad won't know me, I only saw him those few times he came over to the quarry and a couple of times when we went in the van to a trial, sitting in the back on the wheelarches... this would have been '76 and '77. Plus a few times at the shop around the same time when my mate Neil was working there as apprentice. When they had that crazy dog that chased cars down Slade Road. I actually saw more of Roy as he was a member of my club at that time, Sutton Town, in the 80s. I doubt Roy would know me by name but he might still recognise me. Last time I saw him was when he MOT'd my TYZ about 10 or 12 years ago If you're at the AMCA trial this Sunday, I'll be there on my Bultaco or Ossa MAR.

Nice job, you ought to market that.

I didn't remember it looking like that, if your dad is Norman? I remember Norman riding a Bantam in the 70s, he came over to the quarry sometimes that we used to ride in as kids which is now the golf range and Asda on Queslett road. I went to a couple of trials with them as well, as my mate at the time worked at the shop as an apprentice. I can only remember it as having an alloy tank with orange stripe across it - but it was a long time ago...

Their tubed Radial was utter rubbish. A Pirelli Corsa would have given more grip in mud.

If you have Akront rims on your bikes (like the SWM has) you'd be ok as at normal trials pressure the tubeless tyres sit ok on Akront tubed rims using a tube. No need to change to a tubeless rim to use the tyre. The DID and Takasago rims can be a problem though and I've never been able to run a tubeless tyre on them, they drop into the rim at anything less than 10psi Not sure about other makes as I've never had a bike with anything else.

It says you can't run it tubeless, you have to have a tube inside it. So you have to consider that if you're thinking of fitting a tubeless rear rim and are thinking of entering the trial. This presents a real problem if you have a puncture as you are going to have a real problem getting the tube out as you have to break the bead of a tubeless tyre to get at it. That is very very difficult to do without a bead breaker or something else to hand to do the job. Unlikely during a trial so it could end your day. It's one of the daftest and ill thought out rules - actually acheives nothing.

True, but I've had bikes fitted with a grease nipple there as well.

I'd imagine it only applies to insuring your own bike, in other words a bike that is registered to you, as this is generally a standard requirement to insure a vehicle For a definitive answer you need to speak to the insurers themselves as the answers you get on here will no doubt vary.

It's debatable whether they are any advantage these days - with modern soft linings which can be oversize, then machined down to fit the hub better, brakes are better than they were back in twinshock days I still had perfect working brakes on my Ossa yesterday at the end of the trial which included several sections in streams.

The gearbox and clutch share the same oil - 1 litre - I use Silkolene light. The gearbox drain plug under the engine is the only drain. The small screw towards the lower front of the clutch case is the level plug, not a drain. You put the oil in through the inspection cover by the kickstart

Even if you do, I don't see how it can grease the bushes. If one is fitted (there is a pre-drilled hole in the swingarm) and you pump grease in, as far as I can tell, all it will do is fill the cavity in the middle of the tube between the two bushes. How can it actually get into the bush itself? Don't you need to modify the spindle with holes / grooves so that the grease can actually get between the bush / spindle - using new bolts possibly, that are drilled and have a grease nipple in the end, the bolt also has holes drilled cross-sectionally, so that when you pump the grease in, it can escape through the holes in the bolt, through the holes in the spindle and sit in the grooves which will keep the bush face with the spindle lubricated? Or something like that anyway...

Personally, I favour the Castrol oil over Silkolene as Silkolene used to gum up the exhaust with its oily residue whereas the Castrol (now called Power 1 I think) is much cleaner. For the rings as well. I run at 50:1 but as said, it's personal choice and you'll get varied answers. I'd say anything between 40 and 60:1 is ok, most I know use 50.

I'd have thought any modern gearbox oil would do the job, such as Silkolene or other manufacturer's equivalent. 600cc As it is separate from the clutch you don't have to consider the affect of the oil on the clutch action, so whether you used say, Silkolene light, medium or heavy, I doubt there would be any difference I use Silkolebe light in mine with no issues If you still have a steel clutch, use ATF in the clutch. 300cc If you have fibre plates, you can still use ATF but not sure if light gearbox oil would be better. I still use ATF and I have Barnett plates.

No-one is going to worry about a TLS brake. There are no rules excluding them anyway, it's a drum brake and a period mod, available on a YZ from '81 I think. Nice bebuild to a nice looking bike - I sincerely hope that you're going to get it absolutely caked in crap at your Miller round. i had a ride recently on Ian Pederby's 200 Whitehawk, same model as yours I think and also has Yam mono forks. It's set up really, really well, as he's spent years sorting it. Rode superbly, a really nice bike.