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Just draining the carb float bowl will not cure the issue. You will need to remove the carb and thoroughly clean any deposits and fuel gelling with care so as not to open up any fixed dimension passageways and jets. Thin wire such as copper could be used to gently push through any passageways and jets. Better still an ultrasonic clean by a professional or garage. Take a old look at the fuel tap too this can also get partially restricted by crude etc. Make sure the feed pipe from tap to carb is clear as well. Once you are certain there is no fault with the fuel side of things and the settings are correct, investigate the ignition further. As the engine starts and runs but hesitated to rev up this could indicate a high tension coil fault, fine when cold but as heat is generated an internal break in the coil winding may be opening up. There’s loads more to check and diagnosing from a distance is not ideal, but I would definitely go for the fuel side of things first. Good luck??

Most likely been exposed to the elements in field somewhere. So that’s just the fuel tap that’s worth saving.?

TY Trials list a piston kit upto 2.00mm oversize £129 have a look. Obviously post and packaging to US will need to be added. Hope you get it sorted.?

You will most likely spend more money getting that tank sorted than it would cost to buy a good tank i.e. from Shedworks as suggested. However if you are looking to keep the bike original then yes all of the bottom needs to be replaced and I dare say the sides and top will need careful sheet metal work.....expensive! When you bear in mind that none of us commenting have actually seen your $100 tank we could be wrong about the interior condition, but I doubt it. Offer $50 and prepare for lots of work, the fuel tap is worth a few dollars.

Nah a rich Russian more like.

You can tell by the bendy legs.

You are probably right, there are more important areas that need money, politicians pay rise, politicians pay rise, they do a good job, they do a good job. Of course HS2 must go....ahead we need to waste as much money as possible just like we do on the E f*****U! Ever had that de ja vu feeling.

Hey I’m going to talk to Boris and get some advice, you know such as what bike to use, suitable helmet ??‍?and a good hairdresser ?‍?too! Being British or should I be English? maybe the House can debate that conundrum and arrive at a unanimous decision before 2023???‍♂️?‍????⏳Anyway I’ll be wearing hobnail boots and red and white footie socks nicely rolled down to give protection to my shins. Boris did mention that the pivotal points should be moved back, so depending on what bike I end up with I guess the footrests will have to be moved back to the rear wheel spindle with suitable rearset brexit pedal and voting lever. With this I ought to be able to bunny hop right around the ballot box and thus aging massive sponsorship from the House. I will of course need to have a practice and training??‍♀️?‍♂️???‍♂️ camp, this will most probably be Dubai☀️ or Mexico☀️☀️however in reality a ⛺️based on Six Hills Way ?Stevenage⛈. My riding jacket will be conservative, the socks were a laborious choice, trousers and jacket will have a liberal application of sponsors labels held on with duct tape. Boris says I can use a similar Helmet to his but not to use a Union Jack as it might upset other countries. So do I go Vertical or Bettaware or British Gas +1 or Raleigh Gripster?????????

Brexit is very relevant, the EU has rules that we in UK abide by but you won’t see much of that in the Spanish cities, towns and villages that I have spent time in. When UK leaves the EU our government will be able to build more hospitals and increase the police force budgets I could drone on but ....oh and our roads might get repaired on a regular basis...councils would have money again.....it’ll still cost money to see a UK world round, that’s assuming we have the land to spare!

Beta Alp, will do the job nicely.

That’s worth saving, three options: 1 get it repaired by a capable specialist. 2 have it sealed to use crappy modern fuel. 3 cut the inner section out to make a shelter/cover for a slimmer alloy tank. Don’t bin it you will regret throwing a piece of history away. If you use the bike in anger and drop the bike it may damage the tank so you could have it done up to look perfect but use it as a show piece and use some other tank for competition use.?

Cos we’re a bunch of money grabbing profiteers. It could also be down to the fact that abroad most of the land is free to use or it’s sponsored and comes at little cost to the organisers. If we did not pay and £30 is a lot to most people then there would probably be no rounds in UK.

Does the rear wheel fit into the swing arm on its own, with adequate clearance either side. You will always have on some bikes the situation where the tyre moves about on low pressure and rubs on the chain guard and the swing arm, exhaust and anything else within about 5mm of the tyre wall/tread. Try building the back of the bike with the drive side damper and spring assembly left off. The opposite side should support the weight, but I would replace the drive side suspension with a piece of solid bar or tube to hold the swing arm level, no twisting. Align the chain to the gearbox by placing a good straight edge or piece of angle iron or tubing alongside the rear sprocket (no chain fitted) you may find that the rear wheel spindle and hub may need the spacers modifying to achieve this. You will also need to check the alignment of the rear wheel to the front, do this with a pair of good straight tubes, I have used ( believe it or not) fluorescent lighting tubes with care....they do work as straight edges....I digress...sorry. Now you have some solid data to go on rather than uncertainties. You say that you have spaced the suspension unit on the drive side by 1mm and this is a tiny amount, you may have to go to 3-5mm. If you don’t grasp the wheel alignment ( no slight on your skill levels) google should help. Now you have straight wheels and hopefully an aligned drive chain. If the wheels are in alignment but the chain isn’t then consider moving the engine about in the frame with washers or spacers, another way is to space the gearbox sprocket with shims to move the sprocket in or out if feasible, I haven’t seen any pictures of the bike so this last mod may not be possible. The rear wheel rim should be central in the swing arm, if it isn’t then the offset needs tweaking, slacken the spokes on the side that is too far over, tighten the spokes on the other side to pull the rim over to the central position in the swing arm. You will need to get the rim re set by a wheel builder or someone who has the technique, possibly you. The last thing that I would consider doing after the initial data gathering is to remove a piece of the swing arm pivot point and fit it in the opposite side temporarily. By moving the swing arm across the frame slightly example 3mm may just give you the clearance you need. I hope that this helps you to arrive at a workable solution. It sounds like a lot of work ( measure twice and cut once ) but in reality an hour should see you in a position to be able to sort the problem. ?

Very worn 1200 grit wet and dry paper, oil and some gentle massaging around and over the scratch area. You may well be able to remove the scratch but you must not create a flat spot so keep the paper well oiled and moving around. Stop every few seconds and clean and inspect the area, you will generate a dull sheen with this method, but it is a tried and tested method used on a variety of components from gearbox shafts to crankshaft big and main bearing journals....it’s called rescuing the apprentices handy work. Once you have spent a minute or two with the wet and dry...ignore dry as you have oil on the paper, get some metal polish Autosolvol is good but there are others. Now with a very small amount of polish and a soft cloth wrap the cloth around the leg like scarf and pull alternately keeping the cloth over the dull area, stop, inspect and continue until you are satisfied, you might not remove all the dullness but it should provide a surface that a new lubed seal can slide over without leaking. l suggest this to you without having seen the scratch but I am going on your description “a little scratch in the stanchion”. So I do not accept any liability if you use the method I have described for you and you make matters worse? What ever you end up doing I hope you are successful, pack the new fork slider seal with either silicon grease or in my case rubber lube grease (red). You might also then try the superglue trick but as the seals are quite flexible getting the scratch gone is favourite.

I suspect that the mountings of the two engines will be slightly different. You need a Montesa expert, I am not, but it does seem to me that you may well be going about sorting the rear wheel clearance the wrong way. Of course if you are not bothered about originality then crack on. If the wheel is moved as far back as possible does this improve the clearance issue, if so some longer rear wheel mounting lugs could be the answer. You can obtain these from a number of trials parts shops, or make them your self...not too difficult. This might slow the steering a tad but if it lets you keep the wider tyre all well and good. Is the narrower rear tyre unsuitable for your riding style, a narrower tyre will let a bit more power out if you get my drift. ?

Slightly different I let my cousins husband...police trained rider etc.....have a go on my treasured Trans Alp (an old un but good). After a fair while on his ride I started to get concerned, as was my cousin. Relief as he returned riding up the road. Brilliant, loved it he exclaimed....but I did drop it....???‍♂️ Scuffed bodywork, bent lever, twisted forks....I ask you. It was dry and sunny so just sheer muppetry!!

The optimum engine operating temperature is 72.5 degrees C be that two stroke or four. That is what an engine tuner will aim for to obtain the best power. Most manufacturers have to take into consideration all of the emission regulations current at the time of manufacture, so you may find that the thermostat is marked 80 degrees or higher, possibly approaching 90. As water boils at 100 degrees C you don’t have much margin, however with the cooling system pressurised by the rad cap the internal temperature will be more like 120 degrees C, that’s why the coolant sprays out everywhere if the cap is removed before allowing to cool down; the coolant literally expands having been pressurised. Coolant under pressure has a lower temp until it reaches the atmosphere then watch out. Because of this pressure less water can be employed thus saving some weight. Add to this an anti freeze, that lowers the freezing point but more importantly raises the boiling point and you have the benefit to use less water still. Confusingly Sherco show and list their thermostat as a temperature or thermal/ thermo switch. This should make electrical continuity at the terminals when immersed in water at a temperature of 90-95 degrees C which should when fitted to the engine turn on the cooling fan. Ensure that you have the correct coolant mix and don’t just bung in any old anti freeze it has to be compatible with aluminium. A good thermometer or better still a digital volt meter with temp probe will give you an accurate idea of the temperature?? PS if you can obtain a switch with a lower temp say 78 degrees you will be saving on engine wear in the long run. An alternative is to hard wire the fan so it is running all the time, this may not be suitable for you but I’d be comfortable knowing it’s on rather than worry about. Exhaust temp is difficult as it depends on how hard the engine is working and how much exhaust gas is flowing ie high revs or low revs and whether you are in Motion on the road or track at speeds that generates a cooling effect or in section with little wind or air flow over the engine.

As a spectator sport, trials has much to offer if the course is in one place. On the other hand a course involving public road use limits the spectator to either the start or if they want to see more then driving to where ever, trying to park, then a slog to the section/s. This ends up being more like hard work than enjoyment. The BBC tv Kick Start programme put trials riding fully in the public eye, both with junior and adult riders attempting ever more challenging obstacles, the tv audience either hoping to see some skilful riding or spectacular offs. At these events there always appeared to be a fairly healthy number of spectators obviously some were rider supporters and parents of the junior riders. But the programme took away the natural sections and challenging hazards that the countryside offered, naturally enough the difficulty in placing cameras in those days to get quality pictures outweighed the “let’s build” a log pile, waterfall etc. Maybe because the land availabilty and then access and parking can be a limiting factor. I know that if I happened to own land suitable for trials then I would welcome any club or organiser because I know what is involved. However, planning and other environmental issues might not make it that easy to allow for a land owner who has never seen a trial. We all know our sport but it’s kept so secluded from the public eye that a great many people see trials as a kind of stunt show, not helped by modern riding techniques being the first thing people think of. That could also be a reason why some of the er.. more mature amongst us hesitate to enter a trial for fear of being seen as a no hoper. At a RIDE magazine invite to test rider skills we all listened to a briefing when there was a tremendous crash. An experienced rider (his description) dropped a brand new bike just throwing his leg over it.....we were supposed to using this bike.....not anymore!!! Compare that experience to that of a rider who wants to do well in a trial ....and that’s the word...a trial...not a test, not a backbreaking strength test....not a machine breaking, parts damaging blast up an ever steeper slippery rock strewn inclined gulley. A trial of man and machine riding a course that sees them enjoying themselves. Achievable trials courses set out with thought as to the type of rider and machinery that might be used or catered for. Call it an alcomers day trial or evening or weekend taking into account those who might like to overnight. I didn’t want to call that an easy trial but that’s the way forward. The next trial could be a little more challenging but still catering for Mr or Madam Average rider, eventually these riders would be gaining confidence and skills to think about tackling more adventurous courses or maybe not, happy with what they have achieved and remaining with that class. Because of where trials take place and accessibility is difficult for spectators trials will always be less popular than m/x, etc. As people on this topic have already suggested the clubs need to promote themselves more in their local areas and jointly together. Clubs banding together to advertise the sport, using community centres to advertise in, getting bike dealers to show club events on their notice boards and in general making a splash of plugging the sport wherever in local papers maybe getting a feature printed in them. Having sponsored both trials and m/x riders and one or two trials it was advertising that brought in the spectators and the competitors. It’s too late to be a Toni Bou or Dougie Lampkin for many of us and the thought of trying some of the obstacles that they clean is a terrifying one. You develop a more vivid imagination as you age and your head tells you it’s going to hurt before you have even unloaded the bike, that has cost a packet. Clubs need to rethink their strategies and try to involve more of the trade, press and promote their club more effectively.?

I’m no fitness master but I’d consider having a good healthy diet concentrating on slow release foods. Plan to take the minimal tools that will cover most normal eventualities and put plastic tube or caps over the sharp items, just in case you fall and end up with a screwdriver stuck in your side. Walk when you can for added exercise. Drink water, little sips and often to get you hydrated. When in action sips only no gulps, you’ll get wind and be uncomfortable. ?

Front engine mounting bolt has no nut on it. But the bike looks really nice, what’s going on with the alloy side panel looks to be bent upwards on the lower edge. Is this why air pipe is wrongly routed?

Think you’ll find that if it was fitted with a bulb horn hen new then that’s how it can stay. Certainly later bikes had to have an electrical horn. Maybe worthwhile visiting the VOSA web site for the exact interpretation. Your M80 is exempt 46+years old. Or have you another?

Footrests aren’t correct so someone’s been modifying. Looks like they have used the footrest mount plate to hold in the rear brake pedal pivot, you can see a relief has been cut into the footrest mount plate. The swing arm spindle does not have enough threads into the nut, probably due to the thick footrest mounting plates. There should be st least 2-3 threads protruding from the securing nut. Remove that shake proof/star washer and any washers on the other side of the swing arm through bolt and that should get you a bit more thread showing, use locative on the threads to secure the nut. I personally don’t think the rear brake pedal pivot is in the wrong place, it looks just like mine 72 Model 80??

Quite right a 71 Model M80 is tax and mot exempt. My 72 M80 was already reg. for the road. You might need a dating letter for the frame and possibly Bultaco UK / InMotion May be able to help. Possibly the details shown on Team Bultaco date your bike pages could be used as evidence to year of manufacture. If you are going on road during daytime only then you only need an audible method of warning such as a bulb horn and of course a legal number plate. Tyres would need to be roadworthy as indeed the rest of the bike. You could use a battery powered horn or even a 6volt horn powered from the lighting coil. InMotion supplied me with a new LT coil which had an extra wire (red) to power the horn. With no lights you are at the mercy of the lighting laws and Mother Nature, should she decide to rain on you then you will need either to stop and wait for the rain to stop or just hope and go for it. If your M80 is going to wear lights then you will need a stop light as well. Theres another web site where this mot road worthy issue has been done to death. No lights at all means exactly that if you were having an mot test then the tester would add daytime use only. That really means no lights on the machine. Dont forget that your number plate can be white letters and numbers on a black background, I dare say you could use a metal show plate with silver reg no. I’ve finished my M80 and am looking to my next project bike. If I can help with any info, parts etc. Give me a pm??

I’ve seen a few speedway bikes transported by what must be pretty much the same type of rear tow ball mounted arrangement. Now if the speedway rider is going to race abroad then that makes entire sense as they will possibly be charged for just one vehicle. Ditto for a foreign rider coming to UK ( they might decide not though if they read some of the comments on this topic). Nebulous, your last post has deeply saddened me. Like many of us we have friends or relatives that are going through the hell that any of your ailments will cause. I appreciate that these will play on anyone’s mind and be a constant reminder that we are all mortal. I am undergoing tests, my partner has just come out of breast cancer hell, my brother in law has stage 4 stomach and colon cancer and receives palliative care and my mother is CKD stage 4. So if I have offended you by quoting anything you felt was too much then I apologise, it’s easy to do but it is meant in the spirit of the word.

The frame mods, whether lower tubes in place or removed all look very professional and neat. As added info, I’m sure you’ll be aware but I’d like to mention that the lower frame tubes can rub on the engine cases if too close, caused by rock and hard surface contact distortion, wearing away the casting and distorting mating faces. A dense rubber type mat or strip would help cushion any impact between bash plate flex and the underside of the engine. I’ve attached photos of my M80 Bultaco frame with 6mm bash plate, sorry I don’t have one with the rubber strip, but I used ‘temporarily’ rubber workshop floor mat ( sounds awful but it works and serves as a template) until I can get hold of something more substantial. I have heard of someone using a piece of conveyor belt, but I’ll keep looking.? NB the bash plate has been tidied up after these photos were taken, but you can see where the engine had been rubbing itself away on the topsides of the lower frame tubes.