woody

Definitely a 348 tank? They were always fibreglass as far as I remember. Only the later Cota 350 and MH349 were plastic I thought

Are you sure you're reading the numbers correctly. A 210 is a Matador, the picture is definitely a Sherpa. Not the best picture but from what I can see it has the features of a 175. Colours mean nothing as it could have been stripped bare and repainted, engine / forks could have been stripped and polished The 175cc is a model 221 so is the first 2 missing / rubbed out? Are you mis-reading it. The digit following the 221 would be a 0 so if your missing the first 2 it gives 210. It's definitely not a model 210. Both the engine and frame number should be preceded by a letter M for the motor and B for the frame, so M-221 and B-221. The M and the B may also be preceded by another letter, can't remember.

210 is a Matador chassis number. The 175 Sherpa has a 221 chassis and engine number

I had a manual for the 247 I once had and the problem with them is that they don't give a written description for the part number, you have to guess from the picture 123 does look like the valve washer, 124 being the valve body. 027 looks as though it is the second part of the valve washer assembly, ( the part that is the ring with holes in on the Bultaco forks - replaced with a square shim on some 340 forks) Not sure what 025 is but 023 is the piston with 116 the circlip that secures it to the damper rod. You reaslly need someone with a set they can strip and look at, they are the same forks on the 348 and early 349, probably 172 and early 200 as well.

Yes you need NOVA registration of the chassis number before DVLA will issue a reg. Engine number being different isn't an issue, they won't care. NOVA was never intended and therefore is not designed for registering old vehicles but DVLA don't understand that so you just have to play the game. It's why it's not straightforward to complete the form. I did it over 12 months ago when it was still fairly new and I had to print the form off and complete it manually and submit it by post. There was a flaw in the design and it was impossible to complete it online. Not sure if it is still the same. Fortunately HMRC were very helpful. They aren't really interested in old vehicles, the system was introduced to stop people directly importing new vehicles and registering them with DVLA without incurring customs duty etc. They seem happy to accept that customs duty would have been paid by the legitimate importer when the bike was imported from new and that being offroad bikes, many may not have been registered originally or, may have lost there registration details over passage of time. In the section about who the vehicle was bought from I just put private sale however many years ago, no details available. I put a covering letter with it explaining that the vehicle was first imported in whatever year by Commerfords who are no longer in business and that duty would have been paid by them at that time. If they're happy they just add the chassis number to the database. As long as it is on there DVLA will begin process of your application. HMRC were very helpful with my telephone enquiries. Unless things have changed, DVLA won't accept a dating letter from Bultaco UK as they are not on their approved list of agents who can verify a vehicle's age. There is a list on the DV;A website somewhere, or you could phone and check. I used the letter from Bultaco UK as evidence of the age to get VMCC to issue the dating letter but I'm not sure how well they perform this service now as the person that used to be dedicated to dating letters left, so may be worth checking with them first. Also, as most insurance companies only offer insurance for a 14 day period against a chassis number, it may be worth checking this with yours. If that is the case, don't take out the insurance until you actually submit the V55 to DVLA, otherwise your insurance will expire before they process your application, and some companies won't extend the 14 day cover, leaving you in s h 1 t street. If you search for NOVA in this particular forum you'll find other topics about it with more info and personal experiences of others.

I thought they came small enough but maybe not after all. Honda fitted them to small bikes such as XR75 - too big?

My money would be on a GXL

Did you ever have a MK3.... You couldn't make them any worse

Looks like a bad position for the oil cooler, no protection, could get caught or drop the bike on that side and it's easily damaged which could be end of trial Pit bike oil coolers look about the right size, usually on ebay.

You'd have to be nuts and I doubt it would be in favour with the traffic police, if at all it's even legal. The view of the vehicle number plate is partially obscured as a minimum offence. Then imagine if it drops into gear whilst in transit.......

It's been a while since I rode in this event so can't remember the course, how much roadwork is involved? Is it just a road crossing or short stint down a lane, or is there some distance involved?

News from the organisers for next year's series There are 8 rounds, 7 new venues, 6 new clubs. Our aim is to rotate the clubs and venues each year to keep the series fresh, there are now 15 clubs interested in hosting events. 22nd March Congleton MCC Mow Cop 19th April Nene Valley MCC Daventry 14th June. Red Rose Classic Lancashire 26th July Zona 1 MCC Gloucestershire 9th August Cornish Centre Wadebridge 23rd August North of England Newcastleton 13th September Aqueduct Classics. Llangollen 26th October. Central Wales Auto. Knighton Website currently being rebuilt by Kia and should be more user friendly in the future. Some rule changes and a new class to follow! Follow updates via the face book page - National Twinshock Championship NOTE: There may be a change to the Red Rose date of 14th June as there are other classic events on both that and the previous weekend (a Miller round and Alvie 2 day) Updates will communicated on the Twinshock Trials Championship facebook page

They changed the fork legs for a different spindle fitting in '72 with the model 91/92 From the model 91 the spindle nut is recessed (like the 198a) along with the new style conical front hub Prior to that, the spindle nut located on the outside of the fork leg and the front wheel was the older style, not the conical type You should be able to modify them ok, from memory. You have to be careful with Bultaco forks, much of the components look the same but there are subtle differences. The forks on 250 models from the 158 to the 190 are shorter than the 350 forks from the same years because of the different frame. The bottom yoke is also not as deep. They reverted to normal length from the 198.

That is this bike, it should have a silver frame, it's been repainted red. Some still had the older type kickstart

349/4 was the first one to have this frame and kicked up swingarm, it followed the white model. Then came the 350 which was essentially the same bike, different colour scheme and some minor detail changes (didn't know about the oil check screw mentioned above) That's what this bike looks like, the 350 variant. I had one when they were new. Great bike apart from the clutch which must date back to the 60s, but the new era twinshocks like Fantics, Armstrong etc were better for the trick riding that was prevalent then. Superb bike for classic events now, which don't require all that trick stuff. The 349 motor is one of the best twinshock engines ever. Then there is the MH349 which is also the same bike, again with different colours. This is the model that was being sold off cheap for £799 by Appleyards during the air-cooled mono era when most new bikes were probably £1600 and more

I've always found the opposite.... They act as a great rear / engine brake as long as the rear tyre has traction. If it is used on a slippery surface, the engine braking affect just stalls the engine as the rear wheel is unable to bite into the surface and overcome the engine braking to keep it rotating, the wheel skids and the engine just stops. There is less engine braking affect without the decrompressor. Pull the decrompressor in on ice and see what happens. I became pretty good at using them as I used to use those fitted to my Bultacos and Ossas a lot back in the 70s, but only if the surface gave the rear tyre something to bite into, otherwise it was front brake only and a whiff of rear with engine braking on slippy descents. Most fun use on the Ossa was on the road and pulling it in on high revs whilst passing bus stops or crowded pavements as the noise scared the cr@p out of people

Had a 325 when it was a couple of years old and liked it but Fantics and Armstrongs etc were on the way in, so it was becoming out dated. Superb motor and gripped really well For today's classic sections they will cope easily. I've a last model 325 tucked away waiting for a rebuild, but there are a couple of Sherpas need finishing first. Intention is to ride it in some Miller rounds and/or twinshock series.

Thanks Sparks - good tip about surface speed of the flywheel, I hadn't thought of that. I think I had the speed about 800 if I can work out the reading correctly... I was actually skimming the face of it, theory being that if I keep the larger diameter, it will retain most of the inertia characteristic whilst being a bit lighter, helping it pick up a bit quicker but not losing inertia and causing it to stall easily. Feels as though I may have taken a bit much off riding it around the garden but won't know really until I get it out under proper conditions. Three attempts at fixing the broken kickstart shaft now and three failures, but you don't know if you don't try... I enjoy having a go but know my limitations... and keep finding new ones. But I've learned from others and taught myself a bit so I can at least do most of the stuff on my own bikes now. All part of the overall experience which culminates in what I enjoy most - riding trials.

Looks as though it is the Cota 350 version but with a red frame, they were silver/grey originally All of the 349 range began 51 so that doesn't help identify it as a specific variant

Too late for the yellow card Sparks, I had to yellow card myself from the lathe this evening following a skirmish with an Ossa ignition flywheel. An attempt to lighten one saw it stage a successful bid for freedom from the chuck. 7lbs of spinning mayhem flew across the bench like one of Barnes Wallace's finest creations. Fortunately the direction it took saw it trapped in the corner at the end of the bench where it finally span and bounced itself to rest. If it had come my way, I may well have a new head with Motoplat stamped on it... A sharp lesson of a little knowledge and ambition far outweighing the skill set.... I did persevere and get it done, but it appears I've taken off too much after trying it on the bike... I won't mention too much detail of the earlier attempt to pin and weld my broken BSA kickstart shaft, but the attempt to start the bike with the 'repaired' shaft, the subsequent cracking sound and accompanying cry of pain, and a kickstart hanging limply from the shaft, may suggest to some that it wasn't the success it first seemed to be... Tomorrow will be a spanners only day

Standard there are two seals per leg, I can't remember the actual thickness of them now, but probably 5 or 6mm . There is no spacer between them. I only use one 10mm thick seal, same size as for the KTM SX65, so if you buy a genuine KTM seal you know it should be good quality. Not sure if the seals have identifying markings as to whether they're rotary or hydraulic but any seal distributor should know. I believe rotary type can leak quite quickly if used in forks.

ok, firstly, when it comes to giving advice on stuff like this I'm not an engineer, so it isn't necessarily the correct way, but it works for me... Fit shoes to brake plate and put in lathe. I made a 'mandrel' to fit the brake plate onto and it is a tight push fit, so the mandrel can be held in the chuck, not the brake plate itself (basically it is just a tight fitting spindle) Then skim the shoes until they will just fit into the hub. I've used a normal metal cutting tool for this (no idea if it is an alloy or steel tool or if there is even any difference) Can't really advise you on chuck speed either, I think it's about 800rpm. With the brake plate sitting on the mandrel, if the tool does snag it just stops the brake plate revolving as the mandrel can continue spinning with the chuck. This way you don't have brake shoes making a break for freedom and dancing around your garage Once you have the shoes so that they just fit into the hub you can either stop at that or, go a bit further. If you stop here the shoes will give a good contact patch onto the lining. You test how much by fitting the brake plate and spindle, applying the brake arm so that the brake just bites and revolving the brake plate several times. Take it out and look at the markings on the shoes to see where they contact. It may be enough Or, you can open the shoes slightly and hold them in that position by cable tying the brake arm or jamming something in the cam to hold them. Now, they won't fit back into the hub as they are slightly open. Put them back in the lathe and skim again. This should only remove material from the wider part of the arc at the cam end initially. Keep skimming until material is being removed from the entire surface so that the circumference of the shoe surface is round again. Now refit into the hub, operate the brake as before and revolve the brake plate. Check the contact area which should now be virtually 100%. If not repeat until you have the contact patch you're happy with.

Are you sure they are proper fork seals and not rotary seals? Why ATF? Use 10W fork oil. May be a combination of rotary seals and ATF that's letting oil through? Otherwise, no idea on that one, if there is no apparent damage to the stanchion surface that would let oil past. Can't see strapping it down would cause it, the oil should just flow through the damper rod. It's really hard impacts that burst seals. MAR forks work pretty well without any mods from my experience. The standard springs are good, if they aren't worn or sagging. You can't say specifically what length spring is required as it depends on the spring being used, so 17" or 19" would both work if they are a correct rating. The bottoming will be due to low oil more likely than the springs. I'd replace with proper fork seals just to be sure (1 of 35 x 47 x 10 in each leg) fill with 180cc of 10W oil and try again and see what happens.

Colin at TY Offroad has rebuilt a good number of TLR and RTL engines http://tyoffroad.weebly.com/

They're all at least 30 years old so regardless of which was the best when new it's no guarantee what state it will be in now. Worn hubs, worn cams, cam bush in brake plate worn, who knows. I've had Honda, TY and Grimeca front wheels over the years which have had pretty useless front brakes. Even the Yamaha motocross brake plate I used in a mono front wheel was no good. All used current off the shelf brake shoes. Now, there are better linings available to have existing shoes relined. Whichever wheel you use, if you have the drum skimmed to ensure it's round / true, get modern oversize linings suitable for trials fitted to the shoes and skim them to fit the hub for full contact, then you'll have a decent brake