woody

When the M159 came out the 350 Sherpa used a bigger bore pipe so earlier model pipes won't fit. You can't buy just a front pipe for the M159 pnwards as the pipe and middle box were a complete unit. You'll need to source another and then cut the silencer off to use the Fecked one. Never tried one so don't know what's involved. The pipe will need to be from the same model, as from 1978 and the model 199, the shape and length of the front pipe changed and may not fit a 159. The manifold was also a different fitting on the later bikes, being bolt on, not slip on with springs. The M182 and M191 are the same bike as a 159 so a pipe off those will fit. But why the Fecked pipe? If the original silencer has lost its silencing, better to repack that, I can't see any advantage to using the aftermarket one.

Glad to help Bill, yes, same one, the bike on Gumtree.

Is this the blue bike ? If it is, from what I can see of it in the pictures it is a mix of a 250cc model 80 frame and tank with the 325cc engine, forks and wheels from a model 125. Top yoke is from the 325 and bottom yoke from the 250. The exhaust looks to be from a later model 250 which fits as the bore size is the same as the early 325. Later 325 had a larger bore exhaust The model 80 is from 1971/72, the model 125 from 1974. They were 325cc but referred to as 350 for some reason. It looks a very nice bike and if it is mechanically as good as it looks then the price is good. The mix of parts is immaterial as to the useability of the bike but some people are obsessed with the matching numbers game - it's irrelevant, it's a trials bike made for throwing up rocks. However, you need to know what's what from a parts / servicing aspect. You need to quote model numbers when buying Bultaco parts as some models overlapped so quoting just a year isn't always sufficient. As others have mentioned DVLA use the chassis to date the bike and won't be interested in the engine. All you need is a dating certificate that states Bultaco Sherpa model number B-80### is a 1971 model - you don't need a date against the engine number. Before you begin the registration process send a V62 to DVLA with the chassis number and they will run a check to see if it is on their system with a registration number. It's worth putting a short covering letter with it saying you've bought the bike with no docs but believe it may have been registered when new but docs have been lost over time. If it is they will send you the V5 and cash your cheque. If it isn't they just write back stating no trace and also return your cheque as they don't charge for no trace.

Pull the decompressor in and give a couple of kicks on wide open throttle to get a bit of fuel through, then with the decompressor still in kick again but let the decompressor out about 1/3 to 1/2 way through its travel. It's trial and error when to let the decompressor out but after a few attempts you'll get it. I always start my 247 Cota like this as well as my Ossa MARs which can have a habit of slipping on the kickstart ratchet against the compression - using the decompressor takes the strain off and stops that happening

The information on the swingarm length is incorrect as it describes the MK1 MAR swingarm as longer than the MK2 whereas it is the other way around, MK1 short and MK2 long. The 1976 MK3 also had the long swingarm not the short one. The TR77 went back to the short swingarm but it says it has the longer one. I guess it's possible some TR77 may have had the longer swingarm, I don't know

I'm not sure what information it is you're looking for now? Glass's guide won't give you anything you don't have already. If it is a 150 which I'm assuming it is from your picture, but you haven't confirmed, then that's all you need for dating it. The other possibility is the previous model, a model 124 but I think 150. It's just that at some point someone has fitted a later tank, probably because the original got smashed or perished - not unusual for a 40 year old trials bike to get altered. Whether it was a UK bike originally doesn't matter, a model 150 is a model 150 and they are all the same wherever the factory sent them, it's just that the UK importer swapped the tank unit for the alloy one due to UK law prohibiting the use of fibreglass tanks on the road. All Spanish trials bikes from '73 on had alloy tanks fitted in the UK. You see the bracket on the frame upright going up to the top of the rear shock? That's where the original tank/seat unit fastens, there's another on the other side. On the top tube at the front of the tank there should be a threaded stud that secures the front of the original tank which is either hidden underneath the tank or has been cut off to accomodate the later tank VMCC won't date a bike for you unless you become a member If you're going to try and re-register it on an age related plate you may have an issue with DVLA as they will probably want a picture of the bike from both sides and maybe to inspect it and if they are on the ball and realise that it has a later tank fitted they could deem it modified and who knows where that could go with DVLA

The tank on yours is from a later blue model, the 199a from 1979. This style tank was introduced on the last red bike, the 199 in 1978. The tank fitted to the 150 is as per the pictures I put up earlier, It was the last Sherpa fitted with the one piece tank seat unit. The next model, the 158/159 had a seperate tank and seat with seperate side panels. The tank on this Sherpa and on the 182/183 and 190/191 was similar to yours but not the same as it didn't taper towards the rear like yours. These three models were pretty much identical From new none of the bikes had a brace on the handlebars in the early to mid 70s, these were introduced later on. The blue bike in the picture was mine and had modern renthals fitted This link will give you pictures of how the factory produced the bikes. As mentioned before the model 150/151 for the UK had a one-off alloy tank in blue/silver and white mudguards not alloy so you won't find factory pictures for that. If you want to see what that looked like check ebay and search for the Haynes manual for Bultaco as it is the bike on the front cover http://cemoto.tripod.com/bultaco.htm

More accurately, a model 150 was produced late 1974 to probably mid 1975 and was then replaced by the next model which was visually very different. From the factory the 150 had a fibreglass one piece tank/seat unit like this: For the UK this was replaced at import with an alloy one piece tank/seat unit like this, as fibreglass had been made illegal for road use: The next model had seperate tank and sidepanel units with a tank similar to yours

The frame number will date it which is on the headstock, I'd guess it's a model 150 from 1975 with a later model tank fitted. If you send the frame and engine numbers to In Motion who are Bultacoi specialists they will provide a dating certificate. Why do you want the certificate, to register it ? https://www.inmotiontrials.com/

Can't help with jetting, Mikunis have too many variables for me to sort out and there is no base setting for a MAR to even start with, so I don't use them. However, might be worth checking which head gasket you have fitted as they range in thickness from 3mm down to about 0.5mm. A MAR isn't the liveliest of bikes anyway, if you snap the throttle it's never going to leap out of your hands, but if you have the 3mm fitted you could go own to a 1mm which should improve pick up. I;m assuming your crank seals are good and timing is ok (you can advance to 3mm BTDC)

Putting it against a wall and slamming it into gear, which is what you'd have to do, is not a good idea. It's the same as having a working clutch and putting it against a wall and slamming it into gear without using the clutch. You could damage the gearbox. If it didn't mash the gears all it will do is spin the wheel. Putting it into gear and rocking it, or riding it round with the clutch engaged until it frees will only work if it is not stuck fast. I've had a TYZ Yamaha with a sticking clutch with the same behaviour as yours and sometimes it could take 10 - 15 minutes of riding by snapping the throttle and bouncing the suspension to free it off. Then one day it wouldn't free off at all and the only cure was to strip it, clean off all the plates and reassemble and it hasn't done it since (ie; cleaning the grooves between each fibre pad and cleaning the pads with brake cleaner and wire brush to remove impregnated oil) As yours is a recurring problem, each time you leave it, if it was mine I'd pull the plates out, it's not a long job. I'd then clean off the steels and replace the friction plates with Barnett friction plates (or even fit a full set of friction and steels) Then make sure it was adjusted correctly and reassemble. I wouldn't use ATF as it isn't what Ossa recommended, I've no idea how effective that is in an old gearbox with bronze bushes. I use Barnett friction plates with standard steels in both of my MARs and because the friction material is better it allows the spring tension to backed off more than normal which gives the benefit of a lighter clutch pull. The clutch also disengages cleaner and very rarely sticks even after standing unused for months

That was the original triangle fitted to the early 5 speeders up to the introduction of the banana. The triangle you buy now as a reproduction seems fine as I have one on my M49 with no restriction issues. I guess it might be empty but it works well enough to mute the sound as the single silencer set up is too noisy

If yours is an M183 it had a 28mm Bing as standard, the 250 used a MK2 Amal. That's not to say the Amal won't work but as already mentioned, it could be running weak and causing the hot running Yes, the M159, 183 and 191 are pretty well the same bike

Banana is noisy compared to the clubfoot. The clubfoot is fine and is not restrictive. Banana maybe a bit restrictive for a later (M159 on) 325 which have a bigger exhaust than the earlier 325. You can modify the clubfoot by cutting the back off the rear box part, cutting all of the baffles out and replacing them with a perforated tube and packing and converting the dual outlet to a single. It's debatable whether you notice any difference other than a deeper tone and maybe a few more revs on the very top end at wide open throttle. The only packing in the clubfoot is in the section that runs from its inlet to just in front of the rear shock. If the bike runs roughly off idle and has a tinny / hollow sound It's probably worth cutting open, cleaning and repacking both middle box and rear silencer front section. Depending on how the bike has run in the past, the middle silencer can either be dry inside and have blown out all of its packing, or be totally gummed up from poor 2 stroke oil and/or wrong mix. Either way the only fix is cut open, clean, ensuring all of the holes are free in the perforated tube and repack,

That one is longer than a MK1 MAR spindle but I imagine you can make it fit with a bit of machining and thread cutting

I have a triangle on my M49. It's an aftermarket Spanish one from In Motion, it quietens the bike down nicely and no loss of performance at all. It could be that there are no baffles in it, I don't know, but the bike runs fine with it fitted.

Page 100 in here might be what you want Hamish. I was looking for a model 10 gear lever and came across the brake pedal https://www.motosdelabuelo.com/pdf/bultaco.pdf

I'm confused as to what advice you're after as well ? You can just buy a barrel and adjuster nut from In Motion

No idea what the message problem was. Can't help with what difference white or grey primer makes sorry, mine was powder coated and a body shop did the tank for me. It normally says on the can which primer to use ? I'd always use 1021 for yellow, it's a nice deep, rich shade. Can't get a picture of my old Gripper on here but this Majesty was 1021

TY OFFROAD have got pistons as well as ring sets. The pistons are both standard and oversize. The oversize he had made and is a quality piston, it's more like a hone oversize than a proper oversize. A good number have been sold with no problems. Check the website https://www.tyoffroad.co.uk/store/c20/ENGINE.html

28mm is the correct size carb for the 199a (all Sherpas in fact with the 'new type' 325 motor from model 159 onwards as they have bigger inlet and exhaust ports than the original 325 engine) Mikunis are really difficult to jet from scratch, as someone else said, so many variables of carb type, needle jets, needles, all of which have to match as you can't just fit any needle to any needle jet. It probably is the right type for the bike but as they weren't standard fitment there is no base setting for jets etc. You rely on someone else having one on the same bike that works properly and using the same. They all have the air screw on the right hand side which is another pain in the a*** feature about them when you have a bike with a right hand exhaust like the Sherpa. Then there's the flooding... The Bing works fine as long as it isn't worn, as with any carb For the jetting you have, 130 is a bit small and you probably need a 150 / 160. The TY main jet size of 240 is misleading as they are sized differently. Put a 240 VM jet in your carb and you'll pour more fuel in to the motor than it can burn, it'll be flowing out of the exhaust OKO 28mm carb works very well and runs pretty well straight out of the box with maybe just a drop of one notch on the needle and pilot jet change. They cost about £65 from Scooter Assassins in Taiwan (ebay) and a set of 10 pilot jets is about £18 - free post. There are cheaper available but they're copies and useless. Or you could buy one from Mid Atlantic trials in USA for about £100 ready jetted, but to be honest they are an easy carb to set up, unlike a Mikuni. I see you're in Hednesford. I'm running a trial (Stafford Auto club) at Milwaich on Sunday a few miles north of Rugeley. Bring your bike up there and we can have a look, if time you can try the OKO off my Sherpa

Not sure there was a workshop manual but there is a parts list that you can download from various free download sites on the net. For engine strip, the engine components and layout are the same as the MAR apart from small updates over the years to gear selector shaft and layshaft bearings which went from bushes to needle rollers. This means you can't swap the gear train from a 'bushed' gearbox to a roller gearbox and vice-versa. They look identical but there are small differences in shaft lengths and diameter. The Gripper has the clutch weight that the MAR doesn't have They have a cush drive, it's behind the clutch crank weight Pistons are very hard to get, you'll probably have to trawl the specialists in Spain or USA, I don't know of any here. The 350 MAR uses the same piston but the pins are in a different location from the Gripper so there may be issues with them fouling in the ports. I guess they could be relocated. But the 350 MAR piston is probably equally hard to find

You say it should be between 1.3 and 1,8mm BTDC with the stator fully clockwise. That's fully retarded. If that is how you like it then that is ok but fully retarded isn't the Ossa recommendation for trials model which is usually 2.5 - 3mm before TDC Ultimately it's the owner's personal choice how they set it

There aren't any actual timing marks, what you do is line up the hole in the flywheel with the hole in the stator plate and that is the firing point, so you just move the stator so that they line up at whatever point before TDC you want it set at. The hole in the flywheel is about 5 o'clock with the engine at TDC (or about 8 o'clock if it has an earlier ignition fitted) To line them up there is an actual motoplat part called a timing pin but you can use something like a pushbike spoke or similar. Did you use a genuine TR80 piston if you have fitted a new piston?

Ultimately it's personal choice, you can set anywhere between 2mm and 3.5mm before TDC depending on the response you want from the engine on pick up from idle