woody

Thanks for the info Sparks, I knew nothing of these Miller produced bikes until now

I meant to say earlier following Cleanorbust's post - I've never even heard or seen any mention before now of a Bulto/Villiers produced by Sammy Miller. Never knew they existed. Be interesting to see one. Explains why the tank looks like early Pursang if it is a copy of a Model 49 tank

No idea what the seat unit is. If you want to properly date the bike look here: http://montesacotatials.blogspot.co.uk/2010/04/247-frame-numbers.html

Tank looks very similar to an early Pursang copy in alloy

You can see pictures of the various models here http://www.ataq.qc.ca/galerie/index.php?folder=/Mus%E9e/Ossa/

I think they are only M7 on later bikes, all of my early MARs have been M6. Fork pinch bolts and bar clamps are M7 which is a pain

Not just the MK2, all bikes left the factory with fibregalss tanks but after 1973/4, due to a law change prohibiting the use of fibreglass tanks on the road, they were swapped for alloy tanks after import into the UK. Alloy were fitted to all models from then on right through to Grippers. The shape of the fibreglass tanks changed with the Verde model, as did the UK alloy version, but all of the MAR tank variants fit any MAR model The UK alloy tank for the MK2 / MK3 MAR is a different shape from the fibreglass tank so the standard decals for the MK2 / MK3 stripes won't fit, you need UK versions. MK1 had a painted green band, no decal.

Yes, it's an Ossa MAR MK1. Model year from 72 to early 74. Looks in pretty well original condition, just missing the green stripe on the tank and side panels. If the carb is mounted by rubber hose it will be a later model MK1 unless someone has fitted another cylinder, First MK1 came with a bolt on carb. Rear silencer is from another bike, probably a Montesa Cota 247 as it's been cut up a bit. Early MK1 has a peashooter style silencer (which didn't...), kater MK1 has a bullet shape. Sidestand isn't original as they bolted to the other side (not that it matters) although some MK1 didn't have the bracket on the swingarm and came without one.

MK1 and MK2 MAR had different size shock mounts top and bottom. Bottom is 12mm. Top mount is 14mm (maybe 15mm, can't remember) Sounds as though someone has left the metal inserts to the bottom bushes on the swingarm mounts. Not uncommon if they rust on and then when the shock is removed they get left behind. MK3 MAR onwards they changed the top mount to 12mm

Not sure why I read that as 5mm BTDC.... The 124 / 125 models are from '74, not '75 and the crossover gear shaft wasn't introduced until about '77 on Sherpas. Yours will have been modified which is a common mod on the Pursangs. The clutch is usually a single row chain on Sherpas with pin spring retainers until around '77, so sounds as though someone has changed the clutch too - although not inconceivable that Bultaco did some Sherpas with duplex row clutches. Not sure which shaft has been used for the gear change though, as the splines on all Sherpas are the same in my experience, the same gear lever fits the splines on all of my bikes Even with new mudguard braces, you will still get some twisting on the front - all of mine do, regardless of model

The alloy tubes at the bottom of the damper rods are just a push fit. If they've not been removed for years they will be properly stuck on. A couple of things to try. Heat them and use a blunt screwdriver or such like to gently drift them off. Or put the damper rod in the vice vertically, upside down, resting the top side of the alloy tube on the jaws of the vice. Screw a much longer allen bolt into the damper rod a few turns and then after heating the alloy tube tap the allen bolt to push the rod out of the tube. There is no standard jetting for the Bulto on the VM Mikuni so it's trial and error unless someone with the same carb can provide the size they use. No use comparing to the TY175 as it is a different type of Mikuni. A 180 main jet is too big. 130 could be right but I'd buy a 130, 140 and 150 and see which it runs best with. Not all bikes run the same with the same set up. Can't help with timing the Electrex, but it should have a standard timing mark? Standard Sherpa timing on points can be anywhere between 2 - 3.5mm BTDC depending on whether you want sharper or softer throttle response off idle. No idea what that equates to in degrees. Obviously there is no advance with the points and I'm not sure what a modern electronic advances to from what. Advancing to 5mm BTDC sounds a bit extreme to me? Be careful backing the clutch springs off as they will foul the inside of the case if you go too far, although the '74 models usually had a pin retainer for the springs rather than nuts. The later bottom yoke won't make any difference to the fork twisting as it's more to do with the mudguard brace which doesn't look as though it could provide much rigidity on yours. However, the aftermarket braces available these days don't provide that much either.

A bit conservative when a standard TLR Honda costs a minimum £2k.... I've just rebuilt a 1970 Sherpa, no fancy bits, just a straightforward rebuild, no trick alloy bits. Only concession to modern components is a tubeless back rim. Not even electronic ignition. The bike cost me £600. It needed a full engine rebuild which these days is around £500 (pistons are £150, rod kits are £150 plus rebore and crank assembly costs, all new bearings, gaskets, seals - another £120 on top of this if cylinder needs relining) Cost of bike plus full engine rebuild - £1150 so far Then new bars, wheel builds, cables, levers, tyres, frame powder coat and some polishing and re-chroming - another £500 Increases overall cost to £1650 Petrol tank repaired, lined and painted, new seat unit as original too butchered - another £200 Increases overall cost to £1850 These costs are pretty generic to most bikes if rebuilt fully. Yes a few quid can be saved by not indulging in painting / polish / re-chrome and using second hand levers / bars / tyres and not rebuilding wheels if they are solid enough, but you're still looking at around £8 - £900 for a mechanical rebuild to get it fit for use in a trial plus the cost of the bike and you can't get many bikes for £600 now no matter what condition they're in Compulsory purchase at £1500 over my dead body... I suspect you wouldn't have many entries at a trial with that in the rule book

Also make sure you have the centre spacer tube fitted between the bearings as if it is missing, or too short if it's the wrong one, when you tighten the spindle it will push the centre of the bearings inwards and that can cause them to fail pretty quickly

Frame is a MK1 as is the swingarm - MK1 swingarm has the shock mount just over the blob of weld that acts as a stop for the snail cam. MK2 had an extra 1" added to it behind the shock so the shock mount is forward of the snail cam stop. MK1 and MK2 shock position is the same, only difference is the extra 1" arm length behind the shock MK3 swingarm was the MK2 but with shock mounts over the spindle and top shock mounts by bottom screw on sidepanel so they were laid down more than on the later green bikes. Green bikes have the top shock mount lifted to the top screw of the sidepanel, reducing their angle, swingarm shock mounts still over spindle but may have been slightly shorter than MK3. If the engine is a 250, then as mentioned, the barrel is from a later green bike. Head is MK2 or 3. All 350 engines had barrels with cut-outs in the fins so could also be a 350 engine fitted - engine number will confirm. 350 top end won't fit on a 250. All 350 had stub fitting push on carbs, not bolt on. Carb is MK2 Amal which was standard fit to green 250 bikes. The picture is very grained, does it have a reed valve? Rear mudguard loop has been shortened

Not sure if it is the reason why you had to do it, but from memory, the Godden swingarm is narrower across the spindle than the TY frame

I put Montesa by mistake (writing on another forum at the same time) and didn't finish editing it - its a Yam TY wheel, Yam torque arm lug and speedo drive in brake plate Forks are Ossa

Forks are Ossa, wheel looks Montesa 247/348 You can use anything together if you can make them fit

I forgot one of the bikes is accessible so measured the spacer which is 20mm. Spindle length is hard to get whilst in the bike but roughly 23 - 24cm However, as mentioned before the spacer length won't cause your problem. If it's too long the fork leg will be pushed out, not in. Too short and the spindle will just sit further in with more thread showing the other end, the leg will be unaffected and remain in its position. As Steve said above, the missing speedo drive isn't an issue, it is replaced with a spacer Are you sure the spindle isn't picking up inside the leg and pushing it inwards? Take the wheel out and make sure the spindle pushes smoothly and cleanly right though the left side leg.

The first thing I'd suspect is the ignition. A mate of mine has had one of those and it's been back to them four times to sort out and it still won't run properly or anything like. The bike is now back on points and running as it should. I know of someone else who has had nothing but bother with one as well on his 349. First thing I'd do if it was mine is put the points back on without touching anything else. If the problem persists put the original carb back on with the points and take it from there.

I'm guessing you mean that when you have the bike stationary in gear, with the clutch in, it lurches when you slip the clutch out as opposed to moves off smoothly? One possibility is warped plates, another is a sticking cable, another is the slots in the basket where the friction plate 'fingers' slide are badly ridged causing the plates to stick rather than move in and out smoothly. The cable and/or the ridges are the most likely although there may be other reasons. Remove the cable and pull the inner through back and forth, if it is notchy just buy a new one. To examine the basket, you'll have to remove the clutch case. You can see the ridges without having to remove the plates. If it is ridged they can be filed smooth again after removing the plates but it takes a lot of patience.

I was thinking the same, surely if they go up and down in a manner even resembling controlled, they're not elligible for a Pre60 scrambler...

MK1 and MK2 wheels are the same externally so either can be used. Only difference is inside the hub, the MK1 has narrower brake shoes The difference is in the forks. The MK2 fork fits up against the brake plate whereas the MK1 doesn't which is why it has the spacer on that side as well. I won't be able to measure anything until the weekend but if you refit the wheel with the spacer, push the spindle fully home and pump the forks, you'll see if they are in line or not. If they move up and down freely it could be as simple as someone just manually pushing the left side fork leg inwards and clamping it there for some reason

Hard to see how the spindle is pulling the forks in as the left hand leg 'floats' on the spindle. The larger diameter section of the spindle clamps against the spacer which in turn clamps against the bearing when the spindle is tightened. It shouldn't pull the left fork leg in as the spindle should pass right through the leg. If the spacer is too short it will just pull the spindle further through the leg until it meets the spacer. Is it the correct spindle which should look like this http://www.ebay.com/itm/Ossa-Plonker-250-FRONT-WHEEL-AXLE-PIVOT-BOLT-OEM-/400831268520?hash=item5d5367c6a8&vxp=mtr

Other models had the brake on the left but for the MAR, original fitment was always on the right for all versions

It's Alan who had the new fork sliders on his stand at Telford and they can be had with different size bushes to take different diameter stanchions. Looked very nice and very reasonably priced as far as I know. Much better solution than ruining two pairs of forks just to make one. As mentioned above, you just fit your stanchions straight in.