Aircooled Monoshocks

Hello there, I cut a small piece out of the back of the box for a look-see and it is a real mess of packed solid gunge and carbon. I've seen the very helpful pics from Searay175 on 03/11/16 (attached) but can't quite figure out the best place to cut the rear end of the box. There doesn't seem to be a lot of space to cut between the outlet and the mounting bracket like he did and it looks like that would be a real pain to weld up again. Any words of wisdom would be greatly appreciated.

On the verge of locating and (hopefully) purchasing a 2nd plastic tank. Anybody own one of Paul @ Shedworks tank shelters for a ty250 mono? IMO they look great, but... Questions; How easy is it to remove for servicing the air filter? Do you remove the shelter and the tank stays in place each time? Or is the rear tank bolt not fitted and the whole thing pivots up at the front? How strong is it? ie can you sit on it, resting, in between sections? Any other opinions? Thanks in advance.

My two 1984 Yamaha ty250 Mono's.

I am currently rebuilding a JCM 240 Europa - one of the Streit models - I think 1989. I dont appear to have the correct rear brake set up. does any one have a parts diagram or photo of the correct caliper & cylinder? unit I have is a Brembo but the hose looks short, Cylinder mounting screws are 6mm - holes in frame are 8mm. any of you guys have any experience of this?

I am rebuilding a JCM 240 Europa from the late 80s. when I was replacing the fork seals ( I believe these should be Marzocchi ) I found the internals of the 2 forks are completely different. is this normal & does anyone have a parts diagram or any maintenance info on these forks?

In February 2016 i spotted an ad on the net, about a day's drive away for a set of 4 (four) Japan market 1984 ty250 monos plus spares. Had to borrow a pick up and drive there and bring them back. Paid about £820 for the lot. 3 S models and 1 R model, one even a decent runner, and useful spares inc a 5th motor. 3 steel tanks, 1 plastic tank and a majority of the plastics turned to dust. Amazing what UV does...

In the process of putting a Fantic 305 back together and the discs are knackered. Found someone who will make some for me but they have asked if i want wavy ones or just std discs. Question: Ive seen wavy discs on bikes but never knew why. So why would i / should i fit wavy discs and if i do drilled or not ? Sorry but most of my trials experience has been with drum brakes and i have no idea why you would want to fit wavy discs in fact they look like they would feel really weird in use a bit like having distorted drums but i'm probably dead wrong. So please enlighten me before i spend my hard earned. Thanks

Can anybody help with jetting for a Mikuni VM26 for use on the Yamaha TY250R? The carb is new and was supplied supposedly set up specifically for this bike but it is way out. It'll barely run past idle it is SO rich, as if the choke is on. Supplied jetting is - Needle 5L8 Needle Jet 182 N8 Main 125 Pilot 35 Slide 2.0 Or at least I think this is right as I can't see the flipping numbers and had to photo them and zoom in as best I could.. Thanks. Steve.

Hello, So i'm looking for a spare engine for my TR35 Beta (50cc) The current engine spare parts are of Unobtainium or extreme expensive. The clutch is slightly worn out and i hope it will last some time. But i like the bike! So the idea is to run the bike for the rest of the season. And rebuild the bike this winter to twinshock & install new engine. AM6 / DERBI engine. +Lot’s of spare parts +performance upgrades. +Cost of a tuned engine quite high (70cc, good crankshaft, heavy clutch) -> 300-400€ + Engine size is quite the same, some welding required -Still a 50cc gearbox -> easy to fail -Water cooled (cost of radiator, non c…

Looking for a bit of info as to what it is really, I thought it was an Amigo 80 Now I've got the bike looking at images online I'm not sure exactly what it is. I have front disc and rear drum, 21 & 18" wheels, its fitted with a Franco Morini engine but the bore size is marked as 39mm which I think makes it a 50. Unsurprisingly it needs a new rear mudguard, I've tried the one from my Skywalker and its a spot on fit, which seems to rule it out being a Alevin as i found a reference saying they were close but not right. I've messaged Harglo to see if they have any engine spares remaining, if not does anybody know anybody else who may have spares o…

Decided to do an air cooled mono, after spotting a frame, tank and seat for an Armstrong at this years Telford Show. With only 80 ever made, it hasn't been the most straight forward renovation, but its getting close to completion. Everything mechanical has been done and its all running and riding.....however 2 parts have eluded the search. Its missing the airbox and sump shield. I have resigned myself to the fact that both will need to be made from scratch, unless anyone out there has anything they want to sell ? If there was anyone with a complete Armstrong/Can Am mono that would be kind enough to take their bash plate off and draw round it for a pattern, I …

Hi all, I have recently had a TY Mono fully rebuilt (engine) but whilst it runs "ok", comparing it to a friends on Sunday who has recently bought one the engine goes appear more flat. Now that I know the engine itself is 100%, I want to explore the front exhaust (the rear has been replaced with a new box) and also the carb, so questions: 1) I have a brand new Mikuni VM26. Has anyone tried one of these and do they have a starting point for jetting (slide, needle etc) 2) Are replacement front exhausts available or is it a "cut it open and weld it up" affair? thanks, any advice appreciated....

Been noticing that there are a few after market shocks available for the TY250R. Rock shocks, Hagon and now even an Ohlins unit from CTC. Anyone fitted any of these and come to any conclusions on them? My original shock is okay so I'm not needing a replacement, just wondering about whether the performance is much better and what the weight saving is. Cheers Hoodie.

My clutch on my mono has bad it! I'm wondering if anyone knows if the clutch plates are the same from any other yamaha models? I don't fancy paying £58 just for friction plates. Thanks Paul

Is there anyone who still produces aftermarket Pink Mudguards (Fenders) for the TY?

Just before Christmas i got the tip off that Lluis Gallach's Alfer was up for sale. Up to this point it was just one of those factory bikes that had disappeared and i had no idea where it had gone to . Neither had Lluis. So , before it got the chance to disappear once again i went down there to grab some photos and speak to the owner. He turned out to be Felip Gonzalez who built the Alfer and Scorpa bikes with Albert Juvanty. There are some nice old photos in this report on my hobby web. http://www.retrotrials.com/rediscovered---the-factory-alfer-of-lluis-gallach.html

Hello, Trying to learn about TY Yamaha's prepped by John Shirt in the mid 80's. I have one that I know has been in the US since 1985, I've noticed a few items that seem to be different than a stocker, Mine has John Shirt stamped in which appears to be a different style silencer than stock. Can any one tell me what John did to these bikes. Thanks, SB

Anyone know if there is a place (preferably in the USA) that can rebuild a mono shock, shock absorber? Thanks, Jim

Picked up another TY350 today, loaded with spares, including an NOS std bore piston and rings! Score!!

I have a couple broken fins on a Mono cylinder, I'd like to repair them but I'm not sure if the parent material is aluminum or magnesium. I know the side covers are magnesium but not sure about the finned cylinder. If anyone knows which it is, please let me know. Thanks, Jim