woody

Retard the ignition all the way, put a flywheel weight on it and it too will become impossible to stall. It will still pull like a train but won't try and leap out of your hands when you touch the throttle

Hi Giles, it's the return spring on the selector shaft but there are two sizes, so I'll need to measure it when I next get back into the garage. All I know is it is the larger one for the shaft that has the larger diameter piece where the spring locates (rest of the shaft is the same) Not sure about the porting on the MK1 barrel but they had a smaller crank assembly so, I think, different crank compression and should rev up quicker. They fitted a larger crank to the MK2 and the rest from '74 onwards. I had a go on a green 250 recently and was surprised at how well that picked up off the throttle, a fair bit quicker than the MK2 version that I'm more used to

He probably got mixed up with the Sherpa S 175 which wasn't a trials bike but resembled the Lobito. He's definitely referring to the late 60s as he was suggesting Bultaco were trying to compete against the 175cc and other smaller bikes that were being produced at the time, mainly here in the UK. The model 221 was created as a holiday resort rental bike for various holiday destinations in Europe, I think 175cc because that was a restriction on engine capacity without a full licence in parts of Europe. Some were released as trials bikes. Basically a sleeved down 250, model 190

There is no top hat spacer between the wheel and the split bush, it is a normal spacer. There is a top hat bush inside the front brake plate, so make sure you have these the right way around first. However, as the top hat isn't as long as the external spacer, it can't be the cause of the problem. Sometimes the spindle end is a tight fit in the fork leg due to corrosion on both spindle head and inside of spindle housing, the spindle housing may have picked up or burred or there may be muck in there. Take the wheel out, remove the split bush and just try to push the spindle through the leg on its own. If it resists, clean up both housing and spindle head and try again as I've come across this before now which has made it impossible to push the spindle full home without force.

But that was for the 'mappable' throttle body, which the standard throttle body isn't

If it's the original rim, yes they are tubeless

I remember someone telling me a few years ago, they went to a local Honda dealer they were on good terms with to see if they had any leads that would fit the standard throttle body. The assumption being that it must have been mapped in the first place so there must be a way of mapping it. This was before Sandifords went and before Honda wanted all their road bike dealers to stock off-road models. He reckoned they did it with the same mapping lead as used on a CBR600. Np idea if this is fact or not, just reporting what he said.

Unfortunate about the black flag but they knew the penalty for exceeding the stated number of laps and they screwed up. There seems to be fracutres within the HRC pit, not only between the two sides of the garage but within MM crew also. The personnel he brought with him don't seem to trust what's left of Stoner's crew because they think they may pass info to the other side of the garage as Gabbarini has ties with Suppo. It's known that Alzamora wanted all of Stoner's crew out. The Philip Island mess appears to be as a result of MM and crew he brought with him from Moto2 devising a strategy but not telling the rest of the crew. Gabbarini can clearly be seen giving the 'cut' gesture to say it was all over when MM didn't come in on lap 10. They had his bike ready and running and clearly thought he was in. Hernandez and Alzamora (MM's inner circle) had mis-interpreted the rule and thought they could go one more lap. HRC are just saying the team screwed up but it seems a little less simple than that. Also a little justice in a way as MM's recklessness ultimately resulted in Pedrosa crashing out of the previous race, a race he looked as though he may have won. Good article on the PI debacle on Motomatters.com

Jay - it's the inlet that differs, exhaust and transfers are the same on both

That's the last model with the Jumbo chassis, pretty rare and one of the best handling twinshocks as it is. Rotax clutch is the worst aspect of the bikes. The lever mechanism inside the clutch cover is abysmal and is more than half the problem of getting a smooth action as it can foul on the casing. If you take springs out it will most likely slip under real load and high gears. If you lengthen the arm inside the cover to lighten it, it will not get enough throw to clear properly. It's a really tedious juggle to get them to work, yet some (not many) seem to work without any need for tinkering. The best solution is the Aprilia clutch cover with the external arm and different actuator

When you say all the proper Vesty mods, do you mean it was one of the 40 or so bikes that had the swingarm conversion to move the pivot a bit closer to the final drive - based upon the early experiments? Or a copy of Vesty's last bike. This had some pretty big alterations all round and I didn't know they did any replicas of that - engine mounts moved to tilt engine, bashplate reshaped because of engine position, hybrid exhaust, airbox etc.

No, haven't got a contact number or email for him - do you have one? Just managed to source a decent selector shaft from ebay USA though.

Here's a question for those who understand port timing - which I don't Having a few problems with gear selection set up on my '75 310 MAR. Under the bench is another 310 engine I picked up about 25 years ago. It's a later engine from a green bike. I stripped it to compare selector mechanism and set up but whilst apart I thought I'd compare porting as I'd heard that the later bikes were different. On the 75 bike, the inlet port measures 25mm top to bottom and is 25mm high in the barrel (from bottom of liner to bottom of port) On the 79 bike, the inlet port measures 20mm top to bottom and is 30mm high in the barrel On the 79 bike the port is also narrower in width but I couldn't measure by how much. So basically, smaller size all round and higher in the barrel meaning it opens later. On both bikes, the distance from the top of the port to the top of the liner is the same. Both use the same piston. Exhaust port and transfers all appear the same. So the question is, what does this mean and how does it translate to engine performance? Just curious as I'd heard that the later bikes were sharper than the earlier lazier bikes. The later engine has been fitted with a huge counter weight on the clutch in place of the cush drive. It's a home done job but very neat but it weighs nearly as much as an ignition flywheel which suggests someone was trying to calm it down - why I've no idea as they were hardly 350 Bultaco / Montesa power. Finally, anyone any idea of sources for gear selector shafts and return springs - I'm running out of useable items trying to sort this gearbox.

Nice comeback - seems he's on the British humour wavelength Eddie Lejeune could ride either no-stop or stop and hop as sections demanded. The trick riding started long before Tarres and his Beta. Riders were stopping, hopping, reversing on twinshocks. The advent of monos just made it easier and riders like Tarres moved it on a level

One of John Reynolds' Bultacos? One of those has been up for sale on ebay a few times recently. Dave Renham will be able to tell you if it was a bike modded by Commerfords for one of their supported riders.

The Twinshockshop do a set of yokes for the TY Mono with repositioned bar mounting which look as though you can also use risers with http://www.thetwinshockshop.co.uk/parts.php Just scroll down the page and you'll come to them

Not a lot of experience no, a mate has one which I've had a few rides on and it has a nice feel to the chassis. Impressive for a 1968 bike. But... the picture you've posted doesn't look like his and the tank with Cheetah on it is too big for something that would have been fitted to a trials bike. Footrests don't look right either. Obviously the picture doesn't show all of the bike so difficult to tell, but I'm not sure it's a Cheetah See if you can get some pictures of both sides and with the tank and seat off. I think Westyfield has a Cheetah so I guess he could tell you for sure

Chassis number should be stamped on the headstock. Is the frame chrome? They were all chrome as far as I know You don't need the engine number to apply for the V5 - The V62 form you use only asks for the chassis number I think. Plus £25 fee.

When you say no V5, do you mean it has a registration number but you haven't got the log book or that it has never been registered at all and you want to register it? Two completely different processes First one is easy, just complete a V62 which you can download off DVLA website and send it to them with £25 fee. They'll write to the last recorded owner for confirmation but if they get no reply within 2 weeks they issue you with the V5 anyway To register it, you first have to get it (more accurately, the chassis number) recorded on the NOVA database with HMRC as without it being recorded on there DVLA won't issue a registration number for it. Recording it on NOVA tells DVLA that no VAT is due on the vehicle. DVLA now check the NOVA database on every V55/5 registration application they get. If the vehicle isn't recorded on NOVA they send them back to the applicant.

The Cheetah is a nice bike to ride with a more modern feel than you'd expect from a late 60s bike. Chassis is stable and it turns well without having any nasty traits that need 'modernising'. It feels comfortable riding either non-stop or stop/go balancing using the clutch/brakes. Footrest position is high but footrest positioning is personal preference anyway. Villiers 250 is a good engine but there are so many variants... In 'normal' or 'proper' trials trim they're more than adequate for classic trials or B route in modern trials. Things like suspension and brakes are going to depend on what's fitted but with decent units, no geometry changes are necessary to make them work well (my opinion only, obviously, but based upon having ridden one) I've had no problem with old fibreglass tanks using Shell V-power and that includes leaving the fuel in it and not draining. Obviously, some other petrol brands aren't so kind on them. I'll ask someone who has one about the chassis number. Villiers engine numbers are a different matter and it's probably best to speak to Simon at Nametab if no-one on here can help

NOVA only came to being in April this year, so if your Honda was imported in the last couple of years it's doubtful it's going to be on that database, so be prepared to get your application back as requiring NOVA approval. One day, DVLA might grasp how this process is supposed to work and the real reason it was introduced. Until then, we're probably all going to suffer when trying to do things properly in getting old bikes road legal Shame about the Experts, always look forward to and enjoy that event.

Have you had your bike recorded on the NOVA database with HMRC? DVLA will no longer registter an old vehicle that's been imported (ie: anything that wasn't of UK manufacture) without it being recorded on NOVA to confirm no VAT is due. It doesn't mention this anywhere on their website for registering old vehicles on an age related plate but it is a pre-requisite now with no exception I took my V55/5 into the local DVLA office on August 3rd, they checked the paperwork, confirmed it in order and sent the forms to Swansea saying I'd have the registration in about 10 days. They confirmed what I believed, that NOVA wasn't required as the bikes had been in the UK for 30 - 40 years and VAT would have been paid when they were imported. Two of them were too old for VAT anyway... Nearly 3 weeks later I got the paperwork back, rejected because my bikes weren't recorded on NOVA with HMRC. I sent the necessary forms to HMRC - you can do it online or manually by post. I defy anyone to be able to complete them online as they aren't appropriate for old vehicles with the information they require - even HMRC staff couldn't complete it online for me with me reading out the bike details, bike age, date brought into the UK, name of seller etc. The NOVA recording is supposed to be for vehicles brought into the UK independently from April this year to prove VAT has been paid. DVLA don;t seem to understand this and want EVERY application to be recorded on NOVA first. It's nothing to do with HMRC, it's DVLA not being able to apply their own rules properly. If you can complete NOVA online, your vehicle goes onto the database immediately. If you apply by post it takes about 3 weeks turnaround. Mine were eventually put on NOVA and I sent my V/55 applications back to Swansea over a week ago. I'm now hoping they will be registered. I'm waiting to either get tax discs in the post or the applications returned for another missing requirement with the documentation. Nearly 2 months so far for what used to take a matter of hours at the local DVLA office....

From the engines I've worked on over the years the gear cog goes the way it is shown in your photo at the start of the topic. Thanks for the offer re: the parts list but now I know the shim should be there I'll know to look out for it when I get around to stripping the 198a. Everything else is normal Sherpa.

ok, thanks for that, explains why I've never seen one in engines I've worked on. I have a 198a to rebuild so at least I won't be wondering what that shim is doing there when I get around to doing it. Can't recall my 199b having one though

So is that a parts book specifically for the 198/199a? It's not in any of the parts diagrams in manuals I have, or any engine I've ever taken apart, but as I mentioned before, I've never had an 'a' model engine apart