woody

No idea why he told you that about the gearbox, the 303 shares the same engine components as the TR80 Gripper and MAR trials bikes plus numerous other models. Not really describable as a hodge podge either, it's basically an evolution of the TR80, with frame changes presumably eradicating the weak points where they could break. The engine is TR80, exhaust is TR80 redesigned to go over not around the cylinder and a new slimmer tank seat unit was fitted.

Sounds as though you may have a case from an earlier model Pioneer as most early Ossas had small crank assemblies. The early MAR - MK1 from 72/73, engine number begins 34 - also had a smaller crank assembly than the MK2 onwards - yours will be a NK2 as it's 74. As it is a 74 model the layshaft will run in bronze bushes so you need one from 74 - 76 engine, in late 76/77 the layshaft assembly was changed to run in needle rollers not bushes and although the shafts look identical they are slightly different in length and diameter so won't interchange (they might assemble but the gearbox won't work properly) You need an engine from a MAR that begins 21, 22 or 23. I don't know much about Explorer specs but think one beginning 44 or 45 might match the MAR but not sure - if you could find one as they're rare in UK. Ossa ID chart here with chassis numbers (applies to engine also as they're the same) http://ossa.2y.net/ossa/reference/ossaref.html

Hi Sandy, no, sold it some time ago and it went to Denmark. I gave it a total refurb along with a Cota 350 at the same time. Rode both a few times and out of the two I preferred the 350,

Puma bike uses an exhaust from a 335, common mod in Spain

The regs have now come out for the first round, Cotswold Cups on 24th March. It seems this trial has two class categories, one for the new championship and one for the Cotswold Cup. They're available on the South Birmingham MC website http://www.sbmctrials.co.uk

Ossa MAR - probably my favourite trials bike, just glad to help if I can I'm reasonably sure it's a Whitlock frame but another thing that is missing is the rear brake pedal mount as that was located just behind the left hand footrest as the Whitlock didn't have the same brake spindle arrangement as the Ossa frame I think the swingarm is either modified or a replacement. The bottom shock mounts are the wrong type and their positioning is wrong. The Whitlock frame was made for upright shocks as on the MK1 and MK2 MAR and the s/arm mount was just about in line with the front edge of the rear hub, the same location as the MK1 and 2 MAR frame, although the MK1 had a 1 1/4" shorter arm than the MK2. On the TR77 they went back to a short swingarm like the MK1 but put the shock mount right over the spindle. On yours the shock mount is further forward than a TR77 Ossa arm which is why the arm is pushed down at such an angle. This has left the shock angle somewhere between that of an earlier MAR and the TR77 and a steeper angle on the forks with the raised back end, the mounts need to be over the spindle to match the top mount and put the shock angle right. I can't think of anything else but someone else may have something to add as there are other Ossa enthusiasts on here

Only bad if you're bothered about originality I guess. The Whitlock frames were said to be good frames, lighter than the Ossa frame. I've never had one so don't know. I'm reasonably sure it's a Whitlock from what I can see, but not sure about the swingarm as it doesn't look like the Whitlock one, but it could have been altered as well I take it you can't remember the reg number, if not and you're certain of the history of the bike, I'm assuming it would have been registered using the original frame, so you should be ok filling the V62 out and applying for the V5 using the frame number

No. it's not an Ossa frame, it's a close likeness but there are a few differences. It would explain the lack of frame number It could be a modified Whitlock frame as he made some for the earlier MK1 bikes.The footrest hangers look very much Whitlock. There are other likenesses with a Whitlock frame but then there are differences too - sidepanel mounts, additional mount for headsteady (maybe) top shock position moved, bottom shock mounts changed, Swingarm spindle slot is normally open ended on the Whitlock frame. Whitlock frames were nickel (or chrome, not sure) plated as yours is undernneath Miller didn't sell an Ossa frame but Cheney did although it doesn't look like a Cheney. I'd guess at modified Whitlock but not sure

The MK3 generally had black legs but some early versions with the normal up and over chrome front pipe may have had plain alloy (not a criticism of what you've done, I'm no purist or originality obsessive when it comes to paint jobs) The MK3 changed a bit during it's short run, early bikes had the normal MAR exhaust, then they fitted the longer front pipe and some later versions had the TR77 style rear silencer That's a good shine on that paint for silver fox - I might try some of that on a Cotton tank I have to paint

If you're absolutely certain that the engine and frame are the original pairing then the frame number will be the same as the engine number, just prefixed B instead of M. If you fill out DVLA form V62, leaving the reg number blank if you don't know it and using the engine number for the chassis number but prefix B, they will match the chassis number to the reg number and send you the V5. As you will be the registered owner on their records it should simplify things but I'd put a covering letter with the form saying you've lost the V5 which is why you're applying for it I don't know why your frame isn't stamped (replacement maybe?) as generally, after the MK1, the trials bikes were stamped on the headstock, stick on numbers were only used on the MK1 as far as I know If there is a frame somewhere with your number on it and it is registered to someone else, be prepare for some questions from DVLA as t why you're applying for someone else's V5, but from what you've said I'd think that unlikely I'm currently in a tussle with DVLA as someone has sent in a V62 applying for a V5 which I own.... Because it's a Bultaco and the frame and engine numbers didn't match on early bikes because of the way Comerfords sold them, I suspect someone has the engine that came with my bike from the factory, has an unregistered bike, and has applied for a V5 using the engine number as the chassis number in the hope they get a V5. 12 months on and DVLA still haven't sorted it...

VW/Audi Mars red is a good match

Engine numbers start with an M, the frame number starts with the B. The identification chart quotes frame numbers which is why the prefix is B, but the engine and frame numbers matched when the bikes were built. On early MAR the frame number was on a sticker sticker on the headstock but from around 1973 they were stamped into the headstock which is where yours should be

There's not much info on it and as far as I know it's not an 'offical' ACU series which is maybe why there is nothing on their website about it, I haven't looked. Tim's idea was to run as a regional pilot this year with 4 or 5 rounds and if interest took off expand to a full series next year if clubs are interested in organising a round It's called the Central England Classic Championship - Cotswold Cup, Sam Cooper, Greensmith and Guy Fawkes. I haven't seen any dates other than the two Midland Centre trials as they're on our calendar, Sam Cooper 26th May and Greensmith 20th October I just hope there is room on the calender for all these events as more and more are appearing and there are going to be clashes Some info here https://www.oldbikemart.co.uk/coming-up-in-the-december-issue-of-obm-central-england-classic-trials/

Common answer is petrol but if you look at the underneath of the tank is that discoloured too? Usually not, my SWM tank was still perfect yellow underneath and also under the tank badges if they were removed, whereas all surfaces touched by sunlight went darker.The entire tank surface should be affected if it's caused by petrol shouldn't it? Ultra violet from sunlight discolours plastic, just look at garden furniture or kids toys like slides, plastic bikes, swings etc. If these tanks seeped petrol vapour like they're said to, if you left one in a closed garage for any length of time it should reek of petrol, so why don't I smell any?

No is the short answer and I've no idea how or why claims like that originate. Not a full 350, only 302cc so no Bultaco 325 type power on tap but noticeably more than the 250 which is fairly flat. It will pull 2nd or 3rd gear better where the 250 struggles. Later TR77 versions supposedly have sharper porting than the white bikes but never tried one so can't comment. Mine is the first model from 1975 and is a nice bike to ride. Just shave a few ounces off the ignition flywheel for quicker pick up if needed

KIA series in the Spanish class - just me and Chris Myers on Bultacos The rest seem to be facebook queens...

I have one of these kits and it worked fine to remove the drive gear on my 247 https://www.machinemart.co.uk/p/cht249-14-pce-bearing-separator-angle-ge/

The shock bolts are normal M6 on the earlier bikes, MK1 2 and 3, they went to M7 on the green bikes Strangely, the fork yoke bolts are M7 on the earlier bikes and changed to M6 on the later bikes... Fitting the engine, I've never been able to fit one with the barrel in place, or remove it. I take the barrel off before removing and fit it after the engine is back in the frame - I could never do a rubik cube either...

Ford silver fox used around 1970 is a good match but not sure where you can get that now unless a local paint shop can mix you an aerosol for it. I don't know the RAL code. NOTE - If you use Halfords paint it will dissolve at the merest touch of petrol, it will need a coating of petrol proof lacquer otherwise you'll be really peed off with the outcome. And whereas Halfords paint does spray very nicely and evenly out of the can and leaves a really nice finish, their petrol proof lacquer doesn't, it splutters out so you need to be very careful when applying it

This is the same casing as Scotty's bike as all the MAR models had the same casing it's just that the one in your picture is in original condition. Many UK bikes had their casings modified with the slot cut in and the back end cut off to relieve mud build up and also to help hook the chain back on using the slot should it have come off the engine sprocket. See the casing in the picture on my bike. The back end of the case can also get smashed off by a chain derail and it's not uncommon for the bottom rear screw mount to be missing altogether. You're right about the mudguard brackets which is a good ID point but it looked as though it is missing in the picture. I was just meaning the basic frame is the same - on all MAR models in fact apart from the top shock mounts on MK3 and green bikes. I think the Verde also has the short swingarm and mudguard bracket I think Scotty's bike is a MK1 with replacement tank and panels rather than a bitsa, in which case the forks and wheels should be MK1 also

It is a MAR. The MAR ran from '71 right through to '79 and changed little. The MK1 ran from '71 - '73. In '74 it became the MK2 MAR with a longer swingarm, bigger crank assembly and the inlet was changed for a push on not bolt on carb. Hubs changed (although externally looking the same apart from black, not polished) to take slightly bigger brake shoes. Green tank stripe changed from broad stripe from side to side to thinner stripe running lengthways. Biggest change came in '76 with the MK3 when it received angled shocks, longer forks and a longer front pipe. In '77 they changed it from silver frame with white tank and sidepanels to black frame with green tank and sidepanels and changed the rear silencer for an abortionate looking thing stuffed with wire wool. On the green bike the barrel got different porting (maybe) and in '79 the frame and mudguards also went green. It was referred to as the MAR throughout this time but I guess in reality the only true MAR was the MKI1 which ran from '71 - '73 as Mick Andrews had leftt for Yamaha by then. You have a MK1 or MK2 frame (they're the same) which would have been silver. If it has a frame number on the headstock which begins 340--- then it's a MK1. If there is no number it's probably still a MK1 as they usually had a sticker with the chassis number rather than it being stamped. The engine looks MK1 due to the split outer fin on the head and the inlet manifold with studs to take a bolt on carb - these could obviously have been changed in 40 odd years but again, the engine number will tell you as it will also begin 340--- if MK1. You need to know for an engine rebuild as the MK1 had a smaller crank than the following models and the crank pin is stepped. The later pin won't fit. The head is on back to front but it doesn't actually make a difference to the way it will run. The tank is from the last green model, it's not the original. The original would have been fibreglass and a different shape. From MK2 onwards the UK bikes had an alloy replacement, different from the original fibregloass shape, which was the same whether for the white and the green bikes, apart from the last all green bike where it had the extended front part like yours. Side panels also look as though they are from the green bike but there's not enough showing in the picture Bike below is a MK1 with a longer MK2 arm and MK2 barrel. The bottom picture is a MK2 but with the original fibreglass tank

Anyone out there who owns, or knows someone who owns an Ossa Pennine trials. Alan Wright is looking for one to display at Telford in February, so if you have one that you're willing to show or know of someone that might be, then Alan would be keen to hear from you

Press in, just two cups and a ball, same as those in your picture apart from no extensions either side of the middle component for O rings. Mine are a few years old now but assuming they still use the same set up. I'm not familiar with the latter set up you mention but I don't think I actually know what a 'proper' spherical bearing actually is... When I showed my local bearing supplier the bearing/bush from my Magical shock (referring to it as spherical) to see if he could supply them he said no and that they weren't spherical bearings

Very similar to the bearings fitted to the Magical shocks, except those fitted to the pair I had didn't have the O rings. Had them fitted for a few years and didn't give any trouble, no wear etc

If they're being fitted to a MAR then the top shock mount is bigger (at 14mm if I remember - it's bigger anyway) than the bottom mount which is the more common 12mm The way I'd do it is to just fit a normal rubber bush with 14mm id to replace the rose joint bearing. Falcon do different size bushes and as B and J Racing Products in the US are Falcon agents, they'd probably provide some