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Hi Cello, I have 3 Techno's and all 98 black models. Carbs can be an issue especially when leaning the bike over at sections, unless you turn the petrol off. The Mikuni's Vm 26?? are hard to source spares for (I needed a carb top and looked for ages). I'd suggest buying an OKO copy carb off flea bay, (around £30) and try it. As for the float height, I set mine too the manual, floats around level with the carb body, also attach a pipe and with the bowel off simulate its correct position, and manually work the floats to ensure the needle valve stops the fule supply. Best of luck and keep at it, as the Techno's are a great bike and still competitive. Jim.

From what you are saying it seems that you have a problem with an incorrect float height or the float arm is sticking open for whatever reason when you tilt the bike. If it were me I would bend the float arm central tang (that touches the fuel inlet shut off valve) upward slightly so the fuel shuts off with less fuel in the bowl. The reason your bike will not start is that the crank case is flooded out. When this happens take the plug out and clean and dry it off put it back in then try holding the throttle wide open while kicking it over , if it is mildly flooded it will start but not if it is seriously flooded.

Checked the floats , they appear to be intact no cracks etc and float in petrol fine. I turned the fuel on with the carb off the bike no leaks but then fitted it to the bike and it *issed out on the stand, hold the bike vertical and it stopped but still wont start , not even a hint at catching. New plug on the way and will do a compression check while I wait, thks for your suggestions.

Have you pulled the header pipe off the bike. Sounds like it is full of fuel. The crank could be full as well.

I must be the only one in the world that checks a float needle and seat by removing the float bowl and lifting the float with my finger to see if it shuts off the fuel flow at the right height or not at all 🤔

https://www.trialsport.com.au/beta/Manuals/mikuni Forget the REV 3 bit a Techno and REV3 are virtually the same with a different Frame.

@cello have you checked that the floats actually float in a bowl of fuel , over a period of time they can become porous and fuel gets inside stopping them from being sufficiently bouyant.

I run 50% premium pump fuel mixed 50% with 100 octane race fuel, oil is 1% amsoil sabre. Makes the bikes run good and very little smoke or exhaust residue. Ideal float level is when the fuel level is half way up the emulsion tube, because that's when the emulsion tube can function best, if fuel pours out the float bowl vent the seal on the float needle and seat must be failing to regulate the fuel height. ... or a vent pipe is incorrectly routed, that could do it.

Thks Lemur, bike wont start atm so cant tell what effect the front wheel height has. Also the reeds are there to prevent back pressure from the cylinder side not the carb side tbmk so doubt they would have any effect on the problem, I did take a look tonight and they looked fine. I'm wondering if the fuel mixture I put in now is too oily and or if the spark plug has seen better days, replacing it anyway and will bung some neat fuel down the airbox to see if this works. I also cleaned the carb , set the float height to 15mm where the tangs are not level with the casting, slightly downhill looking at it from the side. I hooked the fuel line up switched it on and no leak fitted it to the bike and with the bike on its sidestand switched the fuel on and...........it *issed fuel out again LOL FFIN LOUD, FFIN THING

I've acquired an Aprilia Climber. It's a 280, a 1993 model. Tommy Ahvala won the world title in 1992. So this is the replica, celebrating the Italian manufacturer's world championship victory. I fitted a Paioli RSD fork while waiting for the original Foral to be restored. It looks really nice. I spent a lot of time on the Foral fork. Bertrand Quartier had warned me about the rather poor quality of this component. Indeed, it's not great. Furthermore, a previous disassembly by someone less experienced had damaged the hydraulic system. I repaired it to get it working again. The fork was binding badly. The friction bushings were completely worn out, and the oil... well, it was like crude oil. I found a complete new internal assembly for the hydraulic arm. If my repairs restored functionality, the whole assembly would have been deformed. The poor guidance would have quickly damaged the untreated shaft.

Ciao, ho appena comprato una Montesa Cota 242 e, dato che è rimasta inutilizzata per diversi anni, i dischi della frizione si sono bloccati tra loro. Tuttavia, non riesco ad aprire il campanello. Puoi dirmi come si fa? Grazie mille.

An extra expensive 1.2 pound third party tube/rim lock designed for tubeless tires is randomly installed on a single TRS production bike tube type front wheel 🤔 no, TRS is not that tiny. Now if the rims were to be anodized Pink instead of Red because the manufacturer ran out of anodize materials, TRS is a small enough company to let that slide, but that process doesn't cost extra money and require extra holes drilled to stuff a second rubber inner tube into the front tire.

My '23 TRS has front rim lock 180° from valve. My Beta dirtbike has a Tublis on rear because I put it there. High pressure valve and rimlock incorporated about 4 spokes away from valve. Heck maybe they fitted them for a while. They are a tiny company.

Thank you both. I looked at the eBay item and it was in bad shape. There is substantial damage to the fiberglass and the actual seat is in very poor condition. I have seen the covers and I may have to go that route if I can’t find something better.

Thank you. You get it, don’t just settle for what the docs say. Never forget the power of exercise and fresh air in regard to health. Challenging ourselves with new activities is powerful medicine.

SlowDave, keep showing the doctors they’re wrong. I had an accident (electrocuted) when I was a kid that kept me hospitalized for an entire year. The doctors said I wouldn’t be able to run or ride my bike anymore and that I’d be in a wheelchair in my 50s. Well, I did run again and even skied competitively in college. I’m 65 now and still going strong. Doctors don’t know everything. Also, I had a 1974 TY250 myself that I rode in high school after I was released from the hospital. I’m looking for one now myself. I loved that bike.

You can get reproduction seat covers for cheap and all you have to do is replace the foam. https://www.ebay.com/itm/152173175811?_skw=Yamaha+TY250&itmmeta=01KPVB8X7K75DWFQGXEMP05ASF&hash=item236e3a6403:g:m4UAAOSwxWxg~5Mx&itmprp=enc%3AAQALAAAA8DKQclQvzFwZQpmMrsO4LurgsYX0OYtwnOHG1FqA1%2F4kKnkmO1Tf1vVMAj8S58n4mC%2BLYnlfInRqXIScPwtyzkobh23jam4E7Q9g2reOSh52rFIaNN4L0M9qqSfHPPaW4PSPqfenXRfb2Viv0owk1jo04zzjMlCGznp54xmySvlN4lXY%2BBlFCwrt9aEl1ky0oFIORYTYoP7KkHCURS5NmD%2FvEPsuFzic575YGiyrrX4VpKejiPf4A8dt5HADBGxFVo8pnWJt4rsvnQTq4lAzQPHqi%2FVzqGrbzzJi7qdb7bXYpPBWn%2BbHe%2BztGNRCHkB4sw%3D%3D|tkp%3ABFBMyNSj67Zn

Is it like this? ebay.com/itm/365822976402?_skw=1974+Yamaha+TY250&itmmeta=01KPV5YX13M48FFR2BAG0ZVDFH&hash=item552cbfa192%3Ag%3ATYAAAeSwHcRorLmO&itmprp=enc%3AAQALAAAA0DKQclQvzFwZQpmMrsO4LurGqnycjbd5VkwylZMszIT7wKNntaYRkyc%2FYW8%2BcCnFT7EcmHMszpbwyKBSBChJZICvqQBQh9nSxjEaS7YQFEroUjCgoYMax4z4eKyNTaBA4K%2FRcHticXdmDZmB3iWm%2BfBE5MzgZWWAbKzVmPH0a%2FmCIvXOsBKUmgm5OKS3VeoDvFAyiS94z3rQIelBzQFVpj4uTEeglymppCI9RADj5faRJCqGn4zN%2FejPVOWkTjSUBrAtjm8RhhJL4HVUlaC3mPU%3D%7Ctkp%3ABk9SR-jQ--W2Zw&fits=Year%3A1974%7CMake%3AYamaha%7CModel%3ATY250

Recently I purchased a beater ty250 and I am looking for a seat. They appear to be unavailable so I guess I am going to have to have one made. Have any of you done this? Any recommendations as to who can make it? I do have the fiberglass base but no seat. I have made my own seat pans in the past but I would rater not reinvent the wheel if there is a supplier out there. I am located in the US. Thanks

Hi All, I am new here and new to trials. I recently purchased a beater 1974 ty250 that I am starting to go through. I have 3 other bikes, Husky FE 350s, BSA B50 MX and a BMW r75/5. I have a bad habit of slowing down and falling over. I figured working on my balance is a good idea, a good excuse to buy another bike anyway. 25 years ago I was diagnosed with a rare neurological condition like MS and I was told I had a wheelchair in my future. I have been working hard to prove the docs wrong ever since.

Jetting seems on the rich side for a small 4 stroke. OKO come with smaller jets than that as standard, can't remember what 24mm come with but 26mm have 48 pilot and 112 main. On 2-strokes that jetting generally works fine on anything, maybe a 50 or 52 pilot and drop the needle one notch from centre - this is what I have on various Bultacos 250cc, 340cc and Ossa 250cc, 310cc. Some people also use a JJH needle but I've noticed little to no difference when I tried one

Does it make any difference if you raise or lower the front wheel considerably? That is a tell if the float height is off. for example: it bogs out every time the front wheel is down in a hole, float height is likely off. Inspect the reed valves might also be advised, if there is fuel leak down past the reed valves they must not be sealing very well.

I'm having a mare of a time trying to get the carb to stop *issing out petrol that ultimately causes blk oil to leak out of the exhausat header when kicking the bike over! Let me explain the bike was running ok until I switched over to reserve one day , after a few minutes of running it cut out and has not run properly ever since, I thought there was crap in the carb so refuled the bike and clesaned the carb out , a thousand kicks later still no good so cleaned the carb again and then a while later drained some fuel and even with tha fuel filter there was debris in the sample. I traced this back to a damaged fuel filter so replaced it and clenaed carb again abut still no luck , the bike feels like its binding a bit when i kick it over but still get blak crap out of the header. I cleaned the carb and set the float height and also had the choke to pieces but still it does not fire up , cleaned and checked the plug and still nothing. Weeks later I'm wondering if the floatr height is the issue as looking on the net there seems to be conflicting advice on float height , some say 15mm some say 20mm , some say level tangs with float tangs , I'm confused now and wonder if someone with a working techno on a mikuni carb with plastic floats that slide up and down on pins can give me some advice on how to best set the float height please. I like the techno but now this bike is like the Tardis and i'm losing time not getting anywhere. The carb is now off the bike and I can add photos to check the float setting when I've adjusted it correctly just to confirm. TIA

If you bought it through Mid Atlantic Trials, their guy Roger Annable could undoubtedly give you good advice. If you bought elsewhere, it may be an OKO copy, which are pretty useless.

https://www.jetsrus.com/individual_parts/HUA-1003-PWK 28 jet block oring.html