Beardy Posted July 31, 2023 Report Share Posted July 31, 2023 Hi all. Well finally got a trials bike - better late than never. ‘86 ty250 that’s a bit old and tatty (like it’s owner). Guess i’ll be here a fair bit ad i can’t find a useful workshop manual. Sorting the clutch is the first issue as it’s not good. Lever pulls but the bike barely rolls. I put in 5th a gently rocked it to free it up as it seemed stuck - it did the old leap forward when i put it in gear, clutch lever pulled in! Help always Appreciated. Thanks. Beardy. Quote Link to comment Share on other sites More sharing options...
turbofurball Posted August 1, 2023 Report Share Posted August 1, 2023 Old trials bikes have sticky clutches, especially when they've been sitting for a while. What I do: 1. Change the oil for Dexron III ATF fluid 2. Start the bike, once warmed up a bit give it a push to start rolling and drop it into 1st (with the the clutch in) 3. Ride around with the clutch in until it frees off 4. Give it a good workout, through all the gears, slipping the clutch, get it nice and hot 5. Change the oil for fresh Dexron III 6. Enjoy a free clutch next time (though if it's been sitting for more than a couple of weeks it'll still be a bit sticky again) 1 1 Quote Link to comment Share on other sites More sharing options...
wakbun Posted August 1, 2023 Report Share Posted August 1, 2023 I happen to know the Steve Goode motorcycles has some TY250 handbooks Give him a call on 01938850539 Welcome to the world of trials Quote Link to comment Share on other sites More sharing options...
Beardy Posted August 1, 2023 Author Report Share Posted August 1, 2023 Thanks - good tips already 👍🏻 Is the atf just a good alternative to 10w30 it says to use? Or just better for old bike? I was planning on full fluid flush and renew anyway but good to know that’s normal for the clutch to stick. i found an online manual for the ty350 but it would be dead handy to have a book in the workshop- I’ll give steve a try👍🏻 The old boy i got it off said to run it 40:1 not synthetic - sound ok? What’s the general opinion on mix? Quote Link to comment Share on other sites More sharing options...
thai-ty Posted August 2, 2023 Report Share Posted August 2, 2023 10 hours ago, Beardy said: Thanks - good tips already 👍🏻 Is the atf just a good alternative to 10w30 it says to use? Or just better for old bike? I was planning on full fluid flush and renew anyway but good to know that’s normal for the clutch to stick. i found an online manual for the ty350 but it would be dead handy to have a book in the workshop- I’ll give steve a try👍🏻 The old boy i got it off said to run it 40:1 not synthetic - sound ok? What’s the general opinion on mix? 40:1 non synthetic is what i use in my ty250 monos. 10/30 is what i run in the gearbox, ATF is fine too. They all stick if stood for more than a week or two. Got my workshop manual from Trail and Trials UK, 3 languages, not cheap, even pricier now. I believe there is a ty350 mono manual available online somewhere FOC to download, i have this too and printed out, most of it is useable for the 250 bar bore/piston info. Quote Link to comment Share on other sites More sharing options...
Beardy Posted August 2, 2023 Author Report Share Posted August 2, 2023 Thanks - looks like i on the right lines then 👍🏻 i think that’s the online manual i have? No printer though and £73 is crazy for a printed copy! (Trail & Trial) 1 Quote Link to comment Share on other sites More sharing options...
turbofurball Posted August 2, 2023 Report Share Posted August 2, 2023 The ATF is a good alternative, and really helps with the sticky clutch - I tried switching back to normal oil and it went back to sticking after only a week, switched back to ATF again and it's only a bit sticky after 2 weeks. FWIW I use 50:1 full synthetic 2 stroke oil for my TY175 and it hasn't caused problems (it was rattly and needing a rebuild when I bought it ... I think 5 years ago ... and it's still rattly and needing a rebuild, lol) Quote Link to comment Share on other sites More sharing options...
Beardy Posted August 2, 2023 Author Report Share Posted August 2, 2023 Thanks Turbo Oils on order - went with original spec, see how it goes. Atf is my plan “b”, but your advise is onboard 👍🏻 Thoroughly going over the bike and a few issues so far. Front sprocket nut lose, no locking tab?! Rear brake lever seemed to be held on with paint. Bolt or screw missing? Possible weld job. Looking up how it is supposed to be fixed. The frame looks a bit off set - sure it had a few knocks over the years. I will try and post a picture for reference. And the big one (gulp), right side cover cracked/repaired/leaking a little. i think this may turn out to be quite the project! 😳 Quote Link to comment Share on other sites More sharing options...
turbofurball Posted August 2, 2023 Report Share Posted August 2, 2023 If that's what you *can* see, I wonder what you can't! When I got my TY175 it had been "restored", I only had to completely rebuild everything (though the engine is still on the to-do list) to make it rideable and competition-ready (just in time to move to a place where I no longer compete, lol) Quote Link to comment Share on other sites More sharing options...
lemur Posted August 2, 2023 Report Share Posted August 2, 2023 If my clutch sticks, drags or makes noise then I know there is water in the transmission fluid which in my case is ISO 46 hydraulic oil. It means time to change it. SAE 10-30 is a multi-grade engine oil and transmissions don't need multi-grade oil, transmission oil is never subjected to combustion chamber temperatures, all it lubricates is spur gears, shift forks and a wet clutch. If your engine is left standing for a long period without use and there is any water from condensation or fuel in contact with the clutch then your friction plates will swell. That is what causes the stick and drag. Take all the friction plates out, clean them well and dry them completely before reassembly with fresh oil. Examine the dry plates for consistent thickness in the friction material, sand them flat and even if necessary or replaced damaged plates as required. ATF is Automatic Transmission Fluid and perfect if your motorcycle had an auto transmission with a torque converter and everything is virtually fluid driven. Trials bikes have no auto transmission, no torque converters, what they do have is the same things inside as a farm tractor or heavy construction equipment like an excavator. Hydraulic fluids have a higher operating temperature range and maintain viscosity better than ATF in a broader temperature range. If the small gaps between the clutch friction pads becomes clogged with dirty oil and burnt pad material, then fluid can not escape from inside the clutch pack causing the clutch to slip. Lot of people miss that one. Quote Link to comment Share on other sites More sharing options...
Beardy Posted August 2, 2023 Author Report Share Posted August 2, 2023 So oil out, dirty red so atf i guess? looks like the crack has been JB welded, i will probably do the same for a short term fix. If it doesn’t work it’s replace or weld- both ££££! Didn’t realise the cover was magnesium, finding someone to fix that could be like trying to find rocking horse poop! Brake pedal had sheered so should be able to weld that, small win there. I’ve bent the frame a little at the back, mudguard now sits central - but the does look a bit lop sided by design? As for the rest, well lets see if i can get riding it and if it goes where i point it, it’s a start. I can compare it to another mono if i see one 🤞🏻 Quote Link to comment Share on other sites More sharing options...
Glayne Posted August 3, 2023 Report Share Posted August 3, 2023 Anyone that is good at tig welding should be able to easily tig the magnesium, will just have to find someone with some magnesium filler rod. Actually had a magnesium clutch cover welded yesterday, no big deal. Next time I'm tempted to try it myself, problem is that I'm very mediocre with the tig... and many other things... Quote Link to comment Share on other sites More sharing options...
thai-ty Posted August 3, 2023 Report Share Posted August 3, 2023 13 hours ago, lemur said: If my clutch sticks, drags or makes noise then I know there is water in the transmission fluid which in my case is ISO 46 hydraulic oil. It means time to change it. SAE 10-30 is a multi-grade engine oil and transmissions don't need multi-grade oil, transmission oil is never subjected to combustion chamber temperatures, all it lubricates is spur gears, shift forks and a wet clutch. If your engine is left standing for a long period without use and there is any water from condensation or fuel in contact with the clutch then your friction plates will swell. That is what causes the stick and drag. Take all the friction plates out, clean them well and dry them completely before reassembly with fresh oil. Examine the dry plates for consistent thickness in the friction material, sand them flat and even if necessary or replaced damaged plates as required. ATF is Automatic Transmission Fluid and perfect if your motorcycle had an auto transmission with a torque converter and everything is virtually fluid driven. Trials bikes have no auto transmission, no torque converters, what they do have is the same things inside as a farm tractor or heavy construction equipment like an excavator. Hydraulic fluids have a higher operating temperature range and maintain viscosity better than ATF in a broader temperature range. If the small gaps between the clutch friction pads becomes clogged with dirty oil and burnt pad material, then fluid can not escape from inside the clutch pack causing the clutch to slip. Lot of people miss that one. SAE 10-30W is what Yamaha recommended, when all other oils you mentioned were already available.... Quote Link to comment Share on other sites More sharing options...
b40rt Posted August 4, 2023 Report Share Posted August 4, 2023 On 8/2/2023 at 2:45 PM, lemur said: ATF is Automatic Transmission Fluid and perfect if your motorcycle had an auto transmission with a torque converter and everything is virtually fluid driven. Trials bikes have no auto transmission, no torque converters, what they do have is the same things inside as a farm tractor or heavy construction equipment like an excavator. Hydraulic fluids have a higher operating temperature range and maintain viscosity better than ATF in a broader temperature range. Agreed, defiantly no gears or clutches in an automatic transmission 😂😂😂😂😂 Quote Link to comment Share on other sites More sharing options...
lemur Posted August 5, 2023 Report Share Posted August 5, 2023 12 hours ago, b40rt said: Agreed, defiantly no gears or clutches in an automatic transmission 😂😂😂😂😂 No torque converter in a standard transmission and automatic transmissions use bands not rubberized cork friction plates. Excavator and farm tractor on the other hand has everything including the rubberized cork friction plates for brakes. If you owned an excavator the service manual would indicate that ATF could be used in substitution to the recommended hydraulic oil with the note that "Hydraulic fluids have a higher operating temperature range and maintain viscosity better than ATF in a broader temperature range. " Glad you found it funny. ISO 46 hydraulic has a viscosity of SAE 20 and the recommended was SAE 10W-30 they virtually have the same viscosity. 1 Quote Link to comment Share on other sites More sharing options...
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