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Very good video, close up of the throttle cable removal excellent. ?

You still have the original oil pump control throttle cable. If the oil pump cables are removed the action can still be a bit sluggish. I would be going with a new one piece throttle cable. The TY has a heavy flywheel, Yamahas first attempt with the wide cased TY 250 A had people complaining that the engine was too ‘zappy’! So they tried to tame it and thus you ended up with a slow revving but torquey engine that pulled very well. Another thing to look at is that grip it could be binding on the end of the handlebar and against the throttle body, silicon spray should prove it. Your engine sounds nice, but as I said get the contacts checked. I am assuming your bike is de-oil pumped.

Well actually no I haven’t e-mailed anyone about this, as I have already pointed out I feel that I have done my bit in the past. It is more pertinent that the younger competitors take on the mantle, with fresh ideas and a forward looking outlook. Have you considered a place on the trials working party. Quite frankly I have had my fair share of meetings about meetings with very little outcome to show for it. So I do not feel thus inclined, thank you for the thought.??

There is quite a lot of posts on the subject ‘year of bike’. Think you’ll need to do a frame number check, then ring or e-mail the importers. There will be someone on this site to offer you help that may have the info you need. Welcome...it’s safer off road!?

Looks like the flange is closer at the front than further back. I’d slacken the front bolt a few threads and pull the rear bolt in by the same amount. You may even find that a flat washer between the spring washer and flange may spread the load a little more and improve the fit. However it looks as though the majority reckon it’s ok that’s as long as it doesn’t leak.

Looks like you might have a bodged throttle cable, in other words it might be the original cable that was also connected to the oil pump. If you can just adjust the throttle cable ar each end until the excess slack is down to a minimum. Take out the carb slide and make sure it can actually move up and down in the carb body. The needle should be in the middle position I might be wrong so check that but in any case it’s a good starting point. Those contacts will need to be checked sooner or later. Good luck.

Mickwren, that journey is what you had to do in performing your duties as you chose. It is also unwise to use your real name on any website for obvious reasons. Far from hiding behind a keyboard I comment on suggestions, others interpretation of matters to hand and offer help and advice to those members that seek assistance with machine issues etc. I consider that I have done my bit for motorcycling as a whole. Sponsoring trials when I was a Dealer, helping other club riders with parts and clothing at good discounts. I went to schools and colleges open days to promote my business but also fairly obviously motorcycling and the sport aspects, all in my own time and at costs to me and not my business, including Sunday’s. You are not alone in travelling. I have also attended the BMF East of England show ground both as a sponsor and exhibitor. I have also provided sponsorship to a Motocross rider and a junior Trials rider who went on to be quite successful. I have attended at the Instructors request the then mandatory Star Rider training sessions to demonstrate the course and how to ride it. Again all in my own time and at a cost to me. I also formed a motorcycle club with a fellow likeminded enthusiast, and we held open days for all to come and see what we were about. Lastly, again at cost to me I spent 2 days at a charity festival event raising money for the organising body. This entailed me paying two other people to help me run a ‘try a Trials bike’ for a small donation. Mitsui the Yamaha importers loaned me a TY 125 for free that I had to collect from Chessington and deliver back undamaged and if memory serves me correctly on Sunday evening I deposited some £650 into the organisers charity fund. So maybe before any criticism is levelled, or suggestions about hiding are made I feel that I have done enough and others can and are doing something positive. I must say as a representative of a governing body your response is challenging to say the least. As you were not named in the first post but described as a representative of an official body am I correct in saying that you can claim for your travel and out of pocket expenses! Unlike many of us that do it for the love of the sport. If you don’t get expenses then I apologise for that last bit. When you re-read the original post you will be aware that quite a few influential people ie parents were a little put off by your said announcement. Maybe better explanation was needed.

Have you noticed that more and more youngsters/school children are pulling wheelies on expensive bicycles and even younger children are bouncing about and spinning their scooters (push type) and jumping with both wheels clear of the ground. More impressive to me is the fact that nearly all of them are trying to keep the bike/scooter upright and using body lean to counter act the forces of gravity. Is this down to YouTube and face book or has a new subject been included in the curriculum. Generally popping wheelies riding in traffic is not to be condoned but some have a talent for ‘keeping the front up’ for a long time including cornering while wheelieing, which although damned dangerous and reprehensible, I find to be encouraging. Don’t please get me wrong, these Children should be riding safely and sensibly, but it’s encouraging that the skills that they are developing (knowingly or not) could well be producing the raw material for a whole new nucleus of trials and other Motorcycle sport competitors. Never mind the ACU trying to infer or change their rules to make youth trials more difficult (see other post by smudger984), they instead should be approaching schools and other young people’s organisations to promote Motorcycle Sport and encourage greater emphasis on joining local clubs and describing the benefits of getting involved with other like minded youngsters and adults. The other side of the coin, so to speak could also open up the wider aspects of potential employment within the various aspects of Motorcycle Sport and more. Do any clubs actively undertake promoting the sport that you know of? Heres a question. What do they teach at school now? My neighbour is a head teacher and he seems to be home more than at work, half terms and Baker days excepted. The Shool Children go off to school ? around 08.30 and by 15.00 they’re coming back home?. Now add up the breaks and time walking from classroom to classroom and lunch break and there appears to be less and less time for teaching. I suppose a teacher might counter by saying they need rid of the kids so that they can lesson plan, prepare for inspections, mark homework, have meetings etc etc. The Japanese schools start at 06.00 and go on until late in the day 19.00 if I remember. Opinions appreciated, my post might be judged by some to be off topic but it is all about a sport that helped me in my career choice.?

Bet she would drink quite a few of us ‘under the table’.?

No info on this subject and it doesn’t sound as if it’s been too well thought out, almost like they want to scare youngsters away from our sport. ??‍♂️

Lovely bike exactly as my TY 250 E was....American spec tank decals, Yamaha couldnt sell the TY in the unit numbers they estimated mainly because it was a heavy old lump compared to the Spanish products on offer. The Magnesium covers were susceptible to corroding quickly especially if in the UK they were used for road work and our love of liberal scattering of salt in icy conditions worked its worst on the Magnesium! The frames are strongly built with decent welds...what else would you expect, but they are heavy and many frames were cut and welded to move the engine up and forward slightly to give more ground clearance. The steering head angle was also steepened to quicken up the steering and the top yokes were modified to reduce the ‘tiller effect’. Your side stand looks to have been reshaped somewhat from the original design. I wish you well with your TY.? n

F4SEAT check this first, take the seat off, turn it upside down and look at the seat base, it’s more than likely cracked across the middle. 40 years on and the seat material allows water into the seat foam and then the base rusts and as it wasn’t very strong to begin with the whole seat collapses down onto the top of the water exclusion plate on top of the air filter. This seriously restricts the air actually getting into the air box and the seat foam disintegrates and gets into the inlet manifold stub and coats the inside surface ( it sticks like s*1t to blanket) due to heat. You will know as soon as you lift that seat, then it’s a process of reshaping the air inlet of the air filter box and removing the foam debris, this crap gets into the reed valves etc. A TY 250 E should blip on the throttle more readily. It has the usual tinkle, rattle of most TY’s. Check that the reed valves are intact and actually working as they should, these get tired and it would be a good idea even it’s not the fault to change them for new OE or after market just to ensure that they don’t end up killing the engine by breaking up and getting into the crankcase. The throttle looks slack as clean or bust says...very observant! ?The engine isn’t apparently ‘bogging down’ when you attempt a wheelie, but I’d have to say that the ‘zap’ is missing?. Get the throttle and slide inspected, your looking for wear in the slide and carb body. These carbs are normally good and fairly reliable, but float height and drop need checking carefully. Ensure the choke plunger is operating as it should, and make sure the breather pipes are all fitted and clear, I route mine up inside the top frame tube which conveniently ic exposed just above the carb. Photo included, look for the nylon cap on the mixture screw...missing on many TY’s this was set to be turned in or out a specific amount for road use or competition use...small point but worthy of checking if you want an exact bike. Ignition timing and points/contact breakers gap are worth checking, if the faces of the contact breakers appear to be dark blue this is indicative of the condenser breaking down which will produce a weak spark, another item worth replacing because of age. That’s a flywheel off job so it would be a wise move to check the crankshaft seals. Another potential fault could be that the cylinder base gasket is compromised and leaking. Im sorry I can’t determine the actual causal fault with your ?very tidy looking TY it’s the same year as mine, I have to add that the TY tends to be a little long in the wheelbase so the leverage effect of whacking open the throttle and expecting an enormous wheelie can be very illusive to some, that’s why so many owners went the Majesty route frame wise. Lastly those front forks don’t look very responsive, are they ok? I’m guessing that sorting the throttle and a bit more pull on your part may cure the problem. It’s very difficult to diagnose at a distance but I hope you get a result from the help you’ll get on this website...it is good isn’t it! Last thought, is your bikes oil pump still in place, if not has the mounting area been blanked off with a plate and gasket, that’s a great place for an air leak. Keep us posted on what you find. Have seen your other post and it just makes me wish that I’d kept my E they really are good for an oldie and I used to be a Yamaha Dealer in the late 70’s and 80’s. Fuel tap filter, have you checked to ensure this is not restricting fuel flow to the carb?

Lovely, lovely machining....envious?

Just realised the guy in the video didn’t press down on the kickstart shaft when he pulled the casing off...small point and I realise it’s a full rebuild job, but these tips count if you are just working on the clutch or in the clutch area.?

Maybe the word should be ‘county’. But then again is not Disneyland in France and also in America. So if oni nou says “in your country” I suppose he is correct in his address because he is in another ‘country’. ??‍♂️?????.... It’s really nice in Hythe, Kent. UK the World.

Little or small end rattle can go on for a long time without detriment. Excess piston slap is a bad thing. The best solution is to get someone who knows 2strokes to listen and give advice. As you say you are trying to get it to a shop, but be careful which shop or garage you select. As tshock250 makes a recommendation try there, or ask on here. Is this bike of yours new to you as that noise you can hear might be normal, many strokers tend to rattle a bit, especially as they get older. Make sure the noise you can hear is definitely coming from the top end.?

I’d be going for a 200 or 240 either is a capable bike. ?

Ask some of those riders you’ve been checking for 5 years to invest some time back to give you some help and advice. Oh yes and keep that clean bike clean.?

As ourian explains but not how to pop the seal out. Clean thoroughly around the seal area and the shaft, WD40 or white spirit. Dry off and look carefully around the seal edge of the casing for any burrs or dings, carefully clean with a gentle scraping action using a suitable flat edged blade. Take a thin flat blade screw driver and carefully push in between the seal lip and shaft, downwards at a slight angle. Place a thin piece of aluminium or plywood against the seal housing to protect it from the levering (prying) action you will now need to exert on the seal, try this a number of times working around the seal and as access allows. The seal should start to move outwards and get easier to pry out. Once out clean the housing and check that no damage has been inadvertently done. When installing the new seal there is no need to use heat as the casing will dissipate this rapidly. Apply a thin coating of grease to the inside of the seal lip, wrap a piece of cling film around the shaft and smear some grease on the film this is to protect the seal lip and help it to slide onto the shaft. You could also apply a thin film of sealant around the outside edge of the seal to help it to stay in place. Drive in the seal to the housing as ourian explains. One way used to remove oil seals is to drill a small hole into the seal body and screw in a self tapping screw, repeat on the opposite side and use molegrips to pull the seal out. BEFORE you fit the new seal ensure the output shaft is not ridged or rusty where the seal lip is going to run.??

That move had to be developed from somewhere....the schriber flip. To do that on that bike and then to repeat with the latest machinery would be like riding a feather.

Thanks for the info pallap. What excellent looking machines, I find that I can study anyone of these for quite a time unlike the latest offerings from the Spanish etc. ??

Maybe the words should be ‘They are just not paying attention well enough in school nowadays’!

Well for me you hit the nail squarely on the head....each bike is as different as it’s owner. Every modification made by the owner gives their bike a bit of character, I don’t mean bought online mods, but those modifications the owner has made to improve...for them....the bike. These mods could be the exhaust or different fuel tank, frame mods to the original one and engine and drive line mods. As you say “ there’s a bit of me in the bike”. The latest bikes would only have the bling trick bits that everyone can obtain, unlike the mostly unique mods actually made by the owner. I contacted a club secretary to seek advice about removal of the lower frame rails under the engine on a twinshock of 1972 manufacture. Their reply was that it was a common mod in the day so would not affect legitimacy when the rule book was reasched for. I also think that when all the bikes look similar just as they do from about 97-98 onwards it’s just the riding gear that different. Even the engines nearly all sound the same, both 2 and 4T. Thats something else that provides character with twinshocks and pre 65’s, you know that there is going to be many different engine notes crackling around a course. With reference to your second from last paragraph, I just wonder how some of the ‘old’ talents eg Miller, Smith, Andrews, Peplow etc would get on with the latest bikes and the hopping about and how the Toni Bou’s etc might fare on the old irons!

Before you start taking your Dads bike apart, photograph it from all angles and make a photo record of all aspects of the bike. Take close ups of such things like brake linkages and cable routes, wheel spacer positions etc. You are more than likely going to end up striping the whole bike down especially as it has stood for long. I wouldn’t make getting the engine running a priority as previously suggested there will be all sorts of bad fuel issues and oil in the transmission, there’s the potential for internal rust on exposed gears and hardened seals not just in the engine but the front forks and rear dampers. Sparky do you have the history of this bike and was your Dad a regular competitor. I suspect that there could well be a cache of spares lurking in your fathers garage. The bike will run but that’s not the important part, you need to develop your skills so that you can do your fathers bike proud. You have said that you are prepared to watch and learn which is brilliant and the right way to go. I believe that the 349 was a bit more zappy than the 348 which was a bit milder in the urge department. Maybe you could buy an old moped and practice your mechanical skills on that before going at the Montesa. This is how I approach a Trials bike strip and rebuild. You need either a shelving unit of at least four+ shelves, or a large storage box set. I use the shelves to store the front end, frame, swinging arm fuel tank and shelter if it has one all arranged in order, the wheels and brakes I keep on the floor against a wall. The engine unit lives on a shelf until I am ready got it. The more items you remove the more storage space you need so allow for this if you can. When you watch some of the videos you mention have a look at the backgrounds and see how some people use their workshop space, some are ingenious, others are untidy but that doesn’t mean the work is bad. Britannia Motorcycles is a very good place to start in terms of watching and learning. I hope you enjoy working on your fathers bike and can appreciate the sentiment, the end result is going to be for both of you!

Chain is rubbing against the tensioner arm, this needs to be corrected. When you push the bike the chain is not under any tension apart from the tensioner arm if the chain has been set properly in the first place. When the bike is being driven by the engine the chain will be pulled tight along the top run and clear the frame, except when the suspension is being compressed or on rebound, then the chain will hit parts of the frame ie the swing arm...hence the protectors....it’s not a precise science.