woody

No, just the bushes

If you search the twinshock or Montesa forums you'll find info on removing these - they are tapered and can be stubborn. Look out for O rings on the bolts (either side) that hold the crankcases together as this was Montesa's excellent way of making the gearbox and crankcase oil / air tight. Make a note of which bolts have them for reassembly. There are shims either side of the crankshaft underneath the crank seal carriers When you split the cases try and leave the gearbox sitting in the R/H side casing (ie: final drive side) There are shims on either end of some shafts and you won't want them rolling around on the bench with gear cogs etc. Also, some cogs slide on needle rollers, not cages but 3 loose rollers, so watch they don't fall out as well as they are different lengths for different cogs.

170lbs for a KT.... I doubt the works bikes were that light, have you checked your scales... The 2012 spec lightweight Cubs and James would struggle to achieve that A stock KT is about 215lbs and most of that is the frame which is way too heavy and over-engineered. The motor is actually quite light, especially compared to the TY250 motor which is a huge lump. Even Sammy Miller's Bultacos with the lightweight frames and all his other weight saving tricks were still around 190lbs. As regards the original question, Trials is physical and if you get fatigued doing light physical activity, you are definitely going to get fatigued just riding a bike over rough ground, regardless of the bike. Riding a smaller lighter bike will minimise that, hence your question no doubt, so a TY175 or Fantic 200 would be my choice as both are comparitively light and won't have too much power that they pull you around, which will also tire you out. Both will have more than adequate power for what you need. If you can afford it, a modernised Bantam is about as light as you can get If you choose modern, avoid 250 or bigger as they will pull you around. A 200 Beta is an excellent bike, as is a 4-stroke 125/175/200 Scorpa Another considersation is not just the riding of the bike, it's manhandling it when things go wrong, holding onto it and picking it up again, all of which will tire you quickly if you are already tired from riding. All of the above are easy to start, although a bike that starts in gear is always less hassle. If budget stretches, I know someone who has done a couple of electric start TLR200 Hondas using the ching-chang engines (or whatever they're called) It doesn't get any easier than that...

The fact that it is happening consistently with you operating the kill switch could indicate a possible problem with it - they can and do give problems, particularly cheap versions. I'd replace it as a matter of course. A spark you can see at the plug can get extinguished under cylinder pressure at the speed a kickstart turns the engine if there is a bad connection somewhere. Once a bike is running there is enough power generated to overcome bad connections, so you don't have a problem until you stop it again, or revs drop to almost stall speed. Genuine Yamaha are very good and around £15 http://www.ebay.co.uk/itm/Yamaha-TZ250-89-99-Kill-Switch-Gen-Yam-New-/400369891579?pt=UK_Motorcycle_Parts&hash=item5d37e7b8fb or there are patterns a bit cheaper but for the sake of a few quid I'd get genuine. Timing won't be the cause of the problem and if the bike runs fine when going the timing is likely to be correct anyway. The bike will still start with the timing advanced or retarded. I ran my SWM with the timing on full retard. If the timing was out markedly performance would suffer and it would either pink/knock when hot or suffer from lack of power and have a slow pick up. I'd begin by looking to the kill button and then check that you don't have any nicks in wire insulation from stator to cool. I think you're worrying too much about this 2-stroke 4-stroke thing Nothing to do with starting problems but I'd run it on Shell V-power or equivalent anyway rather than the lower octane stuff. These bikes used to run on 4 star when new. To adjust the timing you just remove the flywheel and rotate the backplate in the direction of the flywheel rotation in order that the points open nearer TDC. But I really wouldn't bother with this as it is not going to solve your problem. Consider fitting a decompressor kit too as these can be used to aid starting. Hold the lever in and give the engine 3 or 4 good kicks on full throttle - this puts a charge into the engine without flooding it, then let the lever out and give one good kick which should see it fire u. With practise you can actually use the decompressor on the 'start kick' also as it removes the resistance from compression when first trying to kick it.

What carburettor is it as you mention a choke lever and the original Amal fitted to the Cota doesn't have one, they have a 'tickler' to flood the carb to help cold starting. If it is fitted with a Mikuni which is a popular conversion, they are buggers for flooding and yes it will affect starting if too much fuel is leaking from the carb down the intake when warm (despite the overflow that lets fuel escape) If it is a Mikuni and it doesn't have one fitted already, swap the float needle for one with a rubber tip to get a better seal when the float height should shut the supply of fuel off. You can get them from Allens. PS - I really wouldn't hold a naked flame over the plug hole to burn off fuel. Bikes have been set on fire simply by the spark from the plug when checking for a spark. Holding a naked flame over the plug hole with all that vapour is a huge risk - add to that possible leakage from the alloy tank due to age and stress related related cracks.... Your flirtation with 2-strokes could be a brief one if you hold to that practise...

It's to cushion the rebound of the forks when they fully extend or 'top out' on rebound. If you pull your forks up hard without any oil in (or even with oil in, in the case of Bultacos...) the clunk you hear is the metal sleeve that's locked in place with a circlip in the botton of the chrome stanchion, comping into contact with the top of the damper rod. This is the impact that the spring softens. The plates they sit on, damping valve and seat, are what help control the oil flow to provide damping. No idea if you can get these parts new anymore, try Bultaco UK as mentioned above or: John Collins at JC Motorcycles Port Talbot Sammy Miller Alternatively, it may be worth looking out for a pair of scrap rusty forks on ebay for the innards, or for used parts, try: Ellastone Offroad breakers Wakefield Offroad have broken lots of trials bikes. You could also use damper rod parts from an Ossa as they are the same forks, the Ossa just has slightly different damping characteristics (better) You can use the damper rod assembly complete off an early Ossa with the shorter forks as they are the same length. Later Ossa forks ('76 on) are longer, so the rods may be longer too, can't remember. The individual parts, the springs, valve and seat, would be fine though.

Fuel isn't a problem as he uses ethanol resistant resin. I've had the 'prototype' tank on my 340 for 12 months now with no problem and I never drain it, it always has fuel in it. I've never actually had a problem with fuel in any of the bikes, both the M49 I used to have and the M92 I've been riding this year used the original Bultaco tanks and neither suffered fuel related problems. The M92 has had fuel in it constantly since I got the bike at the start of the year, I've never drained it. Even the two holes I 'repaired' with araldite have held up. I only use Shell V-power unless I'm away somewhere and can't get it. Edit:- forgot to mention the TY mono cover. The reason for the cover, rather than an actual tank, is purely to tidy up the old weathered plastic tanks. As the tanks are structurally ok they don't need replacing, so the cover is just a way of giving them a new appearance and allows a custom finish as well.

John Collins of JC Motorcycles Port Talbot has a lot of used Bultaco parts so may be able to help. Wakefield offroad have broken loads of trials bikes over the years, so worth a try. Ellastone Offroad breakers Keep a look out on ebay as it's full of Bultaco parts. This part is the same for most Bultacos from the 70s and 80s, so look out for Pursangs, Alpinas etc as well as Sherpas. Even if you end up having to get one from ebay USA it won't cost that much to get it here.

You can buy a new one from Shedworks Bultaco UK and Millers also did them but not sure if they still do now.

All the 'slimline' bikes from M80 up to the 1975 M150/1 had the red fibreglass tank seat unit fitted by the factory. Somewhere around 1974 fibreglass tanks were outlawed in the UK, so the UK importers replaced the tanks with the alloy tank/seat unit, like the one on the front of the Haynes manual. These alloy tanks were blue. It's not unusual for this alloy tank to have been fitted to other models over the years. Your 92 would originally have been sold with the red fibreglass tank/seat.

Colin Leese and Alan Miles lost their bags at the recent Downland Trohy trial. Both bags had been left with the petrol cans in the carpark by an observer who had brought them back from the last but one group of sections, but someone else has picked them up. The bumbag is blue with three pockets and contains some useful tools, the camelbak has a burn on it from a bike exhaust. They'd like to get them back if possible, so if anyone has a blue bumbag and a camelbak they are wondering what to do with, please give Colin a call on 07815 977323

As mentioned above, the spark can look weak when checking, but the HT coils can give trouble on the aftermarket ignitions, so worth checking. They're cheap to replace if warranty has gone..

I'm not saying that is the plug to use, just that it is the plug I have in mine and the bike runs fine on it. I've used between BP5ES and BP7ES with no problems in all my Bults and Ossas. I doubt you'd tell any difference between them. I can't anyway, they're too close together in the heat range. The only plugs I don't use are the micro-tipped things which are no good for trials bikes, they're made for constantly high revving engines and need the revs to keep clean, such as motocross. As soon as you run the engine slowly like on a trials, or as we did, an enduro bike, they can whisker and pack up. No idea whether TTS is semi or fully synthetic, I've used it for years and never had problems, it doesn't gum up rings or exhaust and the piston is always nicely coated when I've removed a cylinder, as is big end. It's what I've run my 340 on in the two years since it was rebuilt and it still sounds like new and it has taken some real abuse in sections and done a lot of roadwork.

Nothing you mention will make it 'easier to start'. The Bultaco will start first time on points and Amal if in good order. I have electronic ignition and a Dellorto on my 340 and it is no different to kick up than my old model 92 which is on points. I think if you spend money on new ignition and new carb, you're going to be disappointed. I'm guessing you're having problems because of the high kickstart, kickstart gear ratio and the compression. Try and get the technique better. Get the kickstart positioned by pulling in the clutch, rotating it then letting it back up to where it is comfortable, just on or past the vertical, then usually one hard push will do it. Don't kick or thrash at it, as that usually just results in a kick-back and your knee in the bars. Not sure a decompressor will help on the Bultaco due to the ratio and short throw but if you can get one fitted relatively cheaply it's worth a try. If you do end up getting electronic and from the UK, i'd get one from Bultaco UK or Rex Caunt (same ignition I think) rather than Electrex. I use 50:1 with Castrol TTS and a two year old rebuilt motor still sounds as new and it has had a good hammering in that time with regular use. Won't make any difference to starting over 40:1 though. Plug is NGKBP6ES Nice Stingray

I remember seeing loads of those tank units when I called into Gateshead (or Sunderland) to get some spares, mid 90s I think. Not a shop though, a unit. There were a lot.... always wondered what happened to them all.

TLM50 bored out to about 70 - 80cc

That's how I remember it, the 323 was out first with the red frame, the 240 followed with the blue frame. I had a 323 from Robinsons in Rochdale, tested one at Back Cowm quarry and bought it. It was my first mono. Really wanted a TY Yam but couldn't afford one and Robinsons were pushing the JCM so got a deal on it. The 323 had a lovely motor and wasn't a bad bike actually, although memory a bit hazy now on the finer points. The shock went but they replaced it no problem but eventually it got traded for a new TY Mono when I could afford one. Not with Robinsons though, those barstewards wouldn't have it back and kept making up all sorts of excuses about not having any TY monos available. That was the last I ever dealt with them.

For some good advice on Bantam builds you could try Jim Pickering on 07850 836571 who builds the Drayton Bantams He has a good number of years experience developing the Bantam trials and has turned out some very nice bikes. The engine in the rigid Bantam that Juan Knight won the Manx Classic on was one of jim's and he has done work for a few other 'names' as well. He can supply parts, build engines or complete bikes. Definitely worth a call if you're looking to build a competitive Bantam.

Thanks Tim, that's the way I was summising. I'd had the magnifying glass on it and tried to suss it from the wear marks but that is a bit outside my technical savvy

Stripped a 198b engine tonight and like a clumsy pratt, caught my foot and let the gearbox that I'd removed complete, roll out of my hand onto the bench. Managed to keep it together, mostly, but the 4th gear, the last small cog on the clutch side of the layshaft, rolled off and onto the floor. So, refititng it presents the problem of which way around, as my useless memory can't remember from previous engine strips. It has a flat face on one side and a small boss on the other. Checked the Bultaco manual, Haynes and Clymer and typically, pictures of the cog show it fitted either way around, depending on which book you look at. Anyone know for sure which way around this cog goes - boss facing outwards towards clutch or inwards to the next gear? I think outwards from what I can remember of other 5-speed rebuilds I've done.

You should find a picture of it here http://www.ataq.qc.ca/galerie/index.php?folder=/Mus%E9e/Montesa/

HaHa - I know what you mean - if ever you find the secret to one of those, let me know...

Well, I think your first problem is that you have to pre-enter and the closing date has passed. Give the secretary a ring and see if they are still taking entries. They may do on the basis that you don't score championship points. Obviously, not a big deal for you as all you want to do is ride in the event. The trial itself is like any other road trial, doesn't make any difference that it is a classic event. Same principles apply. You pay for RTA cover if your own insurance policy doesn't cover you. You'll be given a route card with directions for the road work to the various groups of sections. There are also markers along the route for turn right, left and straight on. Pay attention and don't blindly follow the rider in front who may well be going the wrong way. It happens every event. The trial is usually single lap so you only ride the sections once. You'll either be given a punchcard or the observers will use boards for marking. You'll be given a finish time but it isn't a speed event and you'll have plenty of time to get around, it's only to stop riders hanging around all day waiting for sections to improve if they think they will. If it looks like raining, being first through is better at this trial. That's about the basics of it in a nutshell, but I'd give the secretary a ring asap to check whether you can get an entry. They don't take entries on the day/at the start as a rule, so best check.

Rear sprockets come in two sizes, 46 which was fitted to MK1 and 42 which was fitted to MK2 onwards. MK1 MAR is listed as having 46 / 12 but I'm pretty sure that would be quite high. I've never used a 12 tooth front sprocket. I always used to run 42 / 10 on my MK2 as I prefer low gearing using the smaller rear sprocket but you can have problems with the chain riding over the boss on a 10 tooth sprocket, so 11 is better. 42 / 11 gives higher but perfectly useable gearing in sections and you can use bottom for virtually everything with that. 46 / 11 is not far off the 42 / 10 combination for a lower option. If you don't mind the bigger of the rear sprockets, you could go for 46 / 11 as a lower option. Ultimately it's personal choice, but either of 42 / 11 or 46 / 11 will work ok.

I don't know John, do you really think it would? Surely the same problems would exist around interpretation - also, isn't a Villiers pre-unit, or does it just mean 4-stroke pre-units. Anyway, a bit drastic and unecessary in my view... As a serious point of discussion, I wonder just what the various clubs really seek to achieve, or think they are achieving, with the eligibility rules. It's long been accepted that the bikes are modified and in reality, there is no such thing as a cheat bike any more. Back in the early days of the Sebac and Miller rounds, or even the Scottish Pre65, a few riders were having their bikes modified 'under the skin' to improve performance and at that time it was all hush hush, nothing was admitted. Lots of secrecy and lots of gossip as to who had done what. It was cheating as it was undeclared and gave a distinct performance advantage over those on standard bikes. I remember seeing the Pre65 class bikes turn from unwieldy lumps of iron that bounced through sections like kangaroos on steroids, into lightweight, beautifully crafted machines that now out perform most twinshocks. Isn't it ironic that the Pre65 cut-off was to exclude the early Bultaco which is now hopelessly out-performed by the very bikes (modern variants of course) whose extinction it caused.......? Yet it's too modern to compete against them... As the years rolled on it just became accepted that bikes were going to be modified and the 'silhouette' rule was applied. As long as the bike looked 'period', internal mods were accepted. But this is where it all got subjective as to what exactly is 'period'. You now have the situation whereby any component can be reproduced as long as it is of Pre65 design. But, even if all the parts meet that criteria, the sum of those parts, the complete bike, looks nothing like the 60s original, therefore it's not as though you have 60s looking bikes ascending pipeline in front of scores of appreciative spectators. So why the obsession with components when the bike itself looks more modern than the last twinshocks? Do those spectators really care about that? Do they care if that bike has a Grimeca wheel, or that bike has Montesa or Ossa yokes, or that Cub doesn't have a swan neck frame? Does it really matter if the shock mounts on that BSA differ from original, or that the shocks have been repositioned, or that the rear mudguard loop has been cut-off? Do they look, do they even notice? Would it really detract from the spectacle? So, you have to ask, is there any point to it? To my mind, the development has gone about as far as it can go on non-rigid bikes. What more can be done? Would it be more pragmatic to just say, no hydraulic brakes and clutches, no disc brakes, no reed valves on two strokes, but allow the use of old components from twinshocks or post 65 British bikes such as Spanish or Jap hubs or wheels, Triumph 4 bolt forks. Allow Spanish or Jap forks with the spindle directly under the fork, allow Spanish or Jap yokes. Would this really detract from the spectacle, would it have any sort of detrimental appearance on the bikes themselves, bearing in mind they look nothing like original even when they meet current rules? If you're honest about it, you'd have to say no it wouldn't. It doesn't in other events where no scrutineering takes place and no-one complains about components. So, are clubs just trying to implement rules for the sake of it, out of habit and because they feel that it is what should be done? Is that working? I'd have to say yes and no to those two questions. Maybe it's time to sit back and take a pragmatic view and think about what the objective of the regulations are and whether they achieve that objective. Maybe it's time to relax the rules a little and accept parts that are not accepted at the moment. Look at the following comparisons: A Gremica hub with fins removed looks like a Rickman. Therefore it meets 'Pre65 design' appearance but isn't allowed. You'd be pushed to tell them apart on a bike. Montesa yokes resemble the allowed billet yokes. Montesa aren't allowed. Ossa fork legs resemble Norton or AJS/Matchless. Ossa not allowed Bultaco front hub with fins removed resembles a Rickman. Bultaco not allowed Bultaco rear hub with fins removed is similar to modern billet hub. Bultaco not allowed. Personally, I see no sense in the above. Is it just me that has that view or is there sense in it?