Aircooled Monoshocks

My garelli rear silencer always had a rattle coming from the inside, so now i've rebuilt the engine i thought i should sort the silencer out??? So i've carefully cut the back off the box with an ultra slim cutting disc, and when i opened it up WOW WHAT THE HELL???? inside its got a pipe coming from the front of the box about 4" long going through a plate and then another 3 plates with small openings alternating at the top and bottom and the last plate has a short perferated pipe going out the back??? it seems quite a restrictive design to me, i was thinking about removing the plates and modifiying it to like a modern design with one long perferated pipe and packing a…

hi all i have just got aty 250 mono and it feels like it is riding with the choke on sluggish any ideas

sorry about all these questions but how much and what grade oil should go in the forks? cheers.

Hi ! Anyone ever fit an alloy swingarm wheel & Disc to a TY mono from another bike, it seems it would be a great mod. The early gas-gas look similar ? Mine is a drum brake 84-87 TY250 Mono red frame. With a normal pinging motor ....PWK28 on the way from an yz85

I took the 1984 TY 250 mono [ new to me ] out for a ride after stripping and cleaning the carb. I seemed to run great [ with the TY carb ] and pulled strong on the run. I had ridden some fast logging roads in 4th and 5th gear, then went to a single-track trail up a mountain. An hour into the ride I turned around to come back, and began picking my way down the rough single track in 2nd and 3rd gear using engine compression to slow the decent. 10 minutes later, the engine quit and would not restart, so, out with the spark plug and it looked to be very black. A new plug and I was good to go.....engine started easily and away I went. The black fouling on the plug *felt* on t…

I'm going to start putting the hiro engine back together soon and was wondering if anyone had an engine manual????? it's from my garelli 323 made in 87' nearly the same as the armstrong 320 hiro motor. Help please...??

Hi Guys, I was wondering if anyone has any answers for stopping the pinging or minimising it on my TY250. The motor is fresh and unmodified but it pings it head off. I beleive the original pistons had dishes in the crown ( I could be wrong) but my piston is flat. I'm using 95 octane fuel mixed at 50:1. I have tried raising the needle which improved it a little but its still doing it. I know some peoples answer will be to run it on Avgas but this is really not an option I want to do, as it is road registered and I fill it up at the servo sometimes. I have heard that removing the head gasket to reduce the amount of squish greatly reduces the pinging has anyone who has…

My 84 Yam TY 250 mono has Z spokes with the gold colored rims. There is some lateral runout of about 7mm over 30 deg of the front wheel. How are these wheels for truing? I've never tried truing a Z spoke wheel before. Also, is there a wheel from another bike......newer perhaps, or from another model of Yamaha or other make that would work on the ty 250? Wondering if replacing the whole wheel is any option at all? Cheers.

I have a Delorto PHBH26 carb which I have had from new basicaly I am thinking of off loading it and do not want to mislead any one so am looking for some advice as to how good my memory is (and if the carb is of any use) I owned a 1984 250 mono (first ones out) For some reason at this time it was the thing to do to change the carb to make the bike run better I used it for a year then sold the bike but kept the carb Is my memory correct and is this a thing anyone else remembers. I can't even remember if it was significantly any better than standard any views ??

hi guys im in the middle of sortin my ty250 mono you know that 40 quid pile i bought anyway its got a steel tank on it and its quite rusty inside and was wodering what i can do to sort it , it already has bits rattling around in the bottom and i wondered if there is anything like cure rust i can treat it with , might sound like a daft question but ive been outbid on every tank on evilbay thanks ps anyone know where i can get a tank cover?

Help! I bought a 240 JCM trials bike some time ago which appeared to work perfectly. However, I've since discovered that when the engine is hot, she's difficult, nay impossible, to start. Then when the engine cools down, she starts perfectly again. I suspect that it could be a problem with the little red box thing under the petrol tank which I think is something to do with electronic ignition perhaps??? I've thrashed her with a leafy branch, called her a few unprintable names and locked her away in solitary confinement for a few months but she still flatly refuses to behave. Any technical advice would be much appreciated. http://s605.photobucket.com/albums/tt136/b...nt…

There is an Armstrong TA280,(The alloy framed Rotax engined one.) for sale - advertised on the VMX Competition website.It appears to have frame number 1 and be connected to Steve Saunders.My question is - what do members think this bike is worth ? The asking price is

hello folks my ty250 is fitted with a ngk bp5es sparkplug is this correct? cheers Pat.....

Hello all Iam trying to identify my ty250 mono ,I was told by the seller it was a1989 model but according to the numbers its not ,the engine no is 38V-010***is a 1986 2AF European model and frame no is 4AJ-0020** is a 1991 Japanese Model,can anyone confirm these numbers I can't find much in the way of info on the web,I know its quite easy to build a bike from different parts but just in case I have the wrong info I'am asking on here. cheers.. Pat...

hi guys can anyone help im trying to remove the engine in my ty250 mono but i cant get the bolt out that runs thru the rear of the engine case and the swingarm, i have tried heat, wd40 and i just cant get it to move and cant replace the mains and oil seals till i get it out thanks in advance j ps runing out of knuckles to skin now

Hi Anyone know how to clamp the damper rod without damaging it so I can unscrew (I'm assuming its screwed in??) the damper from the shock base. I've tried a couple of pieces of wood in the vice but can't get enough grip. I want to strip an early TY mono shock (the one without the remote reservoir) so I can give it a good clean etc. Cheers Tim

Yamaha TY 250 mono on ebay item no 260361410268. Anyone know anything about these, also mention of a new exhaust system coming out ?? Sorry I can't do link it doesn't work .

hi all just a quickie need to replace the main bearings in my ty and have found out that the part number is a 6206 c3 thing is are the bearings handed left and right or can i just buy a pair of bearings thanks

hello there can anyone tell me where i can find a copy of a manual or owners handbook for download for a1989 250 mono cheers...........

Hello all, Does anyone know where I could purchase a Piston Kit for 1985 ty250 .75 O/S? I am in Australia and seems to be none here... Thanks Chris