Yamaha

Hello My 74ty 250 starts fine and will run for 10 minutes or so ok then when the throttle is opened it stalls like getting no fuel. Carb out and cleaned several times. Today it seemed to recover for a few moments when I pressed the choke. Vent pipe is not blocked New points and condensers, new crank seal on that one side only, must do clutch side next. Whats left ,carb rubbers or gaskets, reeds Had anyone this issue before.

Questions, angle grinder for port modifications. -I have modified several 2 stroke cylinders with Dremels with decent results, but never upper transfers because I don't have a small enough angle grinder. -I have a trials motorcycle engine TY250 Mono with 68 mm bore that I would like to work on the upper transfers. My 90 degree 1/4 inch angle grinder is too big. -I can't afford a Foredom cable operated with the assorted heads. -If I have to buy something, I'd like to be able to do saw cylinders as small as the 026 44 mm bore. -What is out there that could do a 44 mm bore? I can do electric or air. The low speed dental heads are cheap, but t…

Guys, What is the standard break in proceedure for a new piston, rings, and a bore that has seen another piston? I honed after the first piston with a 280 grit ball hone, but after 3 hours- the rings are still not seated with about 50% contact right now. What oil and ratio should I use or should I re- hone the bore and try again? I have .012" ring gaps at the top of the bore right now. My oil was synthetic Amsoil at 30:1. There are several contact areas disbursed around the inside of the bore about 1" wide. What am I doing wrong or what would you change to get the rings to seat fully? Thanks in advance!

Very quick one, is the RD350 inlet mod the carb rubber as well as the reed block? If so does any material need to be taken out of the inlet. Thanks, new to all this

Took all the lights off- need a good way to cut off the power to the coil- The switches I have are both momentary two wire switches that mount on the handlebars. I think they are meant to ground out the pulses to the primary side of the high tension coil. What has worked for you? Details please!

At the risk of kicking this subject to death- If I put in a full liter of gearcase oil after draining it all out, the dipstick shows an overfull condition- even after running the bike for hours. The oil is about an inch above the top mark on the dipstick even with my modified drain plug which allows oil to level between both sides of the clutch wall. So I am wondering - this is probably soaking up horsepower that could be useful at the back wheel, engine responsiveness and easier engine starts if the clutch was not half immersed in oil. So to me- I've got conflicting information- the book and the marks on the case say to put in 1 liter, but the dipstick says that's…

Guys- I took off all the lights and fitted a set of Domino grips and throttle assembly on the bars- for those of you who have gone this route- what is a good replacement for the kill switch assembly? I don't want a lanyard situation as I don't think it's necessary for my riding style. Any ideas?

Was wondering how much oil and what wt oil should I use in the TY 80. Also does anyone know where to get factory manual also ?

Can somebody with an original TY 250 A tell me what the stock length of the dipstick is? I'm getting 133 mm for just the metal rod below the plastic handle???? The part number on CMSNL is 3221536300, but on there it looks like a plastic one. - I want to make sure I have the right quantity of gearbox oil in there. Thanks for your help!

Guys- I have most of the torque settings in a shop manual for a B model, but I don't have the torque setting for the 4 aluminum cylinder hold down female bolts. Anybody? these are soft aluminum with a hex shaped top (4 each) if that helps- Thanks in advance!

So, I very very stupidly managed to knacker a ty250 twin shock clutch basket. Basically trying to lock it up to take the nut off, snapped a finger off the basket. Kicking myself so much over this stupid mistake, and also as the fingers look almost new, with no noticeable ridges ..... Regret selling my compressor and rattle gun....... Anyway the bike is a Colin Appleyard special, so one of the last produced. We are looking for a basket for this model. I have got it in my head there are 3 variations of clutch used over the years for this bike.... Cannot find anything on ebay using `TY250 clutch` as the search that looks similar. ..>...... However, some photos of a D…

Hi all I am having trouble removing flywheel on 1974 TY250 , using the correct pullers time and patients but no budge. Any recommendations

This might be a tough request to make, but I have a small dilemma. I have a stock 74 TY 250A and I have had everything rebuilt on the engine. But when I tried to install the piston, it touches the flywheel before the flywheel can rotate all the way around. So either I have the wrong piston or the wrong Connecting rod installed. My measurement for the piston skirt is 68.3 mm from the bottom of the lower piston ring to the bottom edge of the piston skirt. Does this seem to be about right? The piston is a genuine Yamaha, from CMS, part number 438-11631-01-96. If anyone has a loose TY 250A -1974 model piston laying around loose they can measure- it …

Any answers/ suggestions are appreciated. I'm knee deep in a 1977 TY-250 build and I'm wondering ... Has anyone decided to remove the factory head and tail/stop light? The bike will never be road legal and I don't plan on taking it out at night so I'm thinking I remove the lighting coil from behind the flywheel and delete the other bulbs and harness. Any thoughts or tips?

J'ai sandblasté et peinturé mon cadre, maintenant l'assemblage commence. J'ai aussi affiché des factures pour votre info. I have sandblasted and painted my frame, now reassembly begins. I have also posted some receipts for your info.

Hi, first post, other than the introductory post in the other forum. I am in the process of getting my TY250 in good running order. In the process of checking the timing and the points gap, I notice that the points don't seem to open at all, no matter how they are adjusted. What am I missing? The bike starts on the first or second kick and runs fine up to half throttle. (I just installed a new carb and ditched the autolube pump, so I have some smoothing out to do. But I wanted to dial in the ignition before I go too far messing with jetting.) Mystified.

Can anyone recommend a restoration company - preferably in Yorkshire - 1983 TY125 owned for 30 years - little use - but now want to put back on the road

Hi does anyone know where to get the progressive springs from. Also people's best upgrades for the 175 that they have done and it's worked well Any info greatly appreciated Neil

I've just been idly meandering around the internet where I discovered a very interesting bike: a 525cc Yamaha trials twinshock, built by a talented French engineer, Frédéric Fleury (?) - see link below. Apparently it was based on a Yamaha XT500. Which reminded me of a photo I saw years ago in a Mick Andrews trials book (forgotten its title, but I remember the book was small which contrasted with the bigger books by Sammy Miller and Don Smith - I still have all three somewhere upstairs). The photo was of a partly constructed 500 trials bike that Mick was building, based on an XT500. For years I wondered if that build was ever completed - apparently it wasn't du…

Hi everyone, I have the opportunity to purchase a very original full size Godden chrome framed Majesty in Australia I have been waiting a long time to get a Majesty 250 or 320 but the chances of finding one of those in Aus is nil so a good clean 200 might be my only choice. I have had many TY's in the past and find both the 250 and 175's have their virtues and their faults, although i'm 100kgs I can ride both competitively and we don't ride many hill climbs here in Aus so the little 175 is not to underpowered. Questions for the brains trust: was the 200 just a bored out 175 or did Shirty do any porting and jetting etc:? Is there any real changes in power between…