Twinshock

This was posted up on the Texastrials site! Looks like a BulDaka to me! Beauty!

Can anyone please tell me the correct amount of oil & grade required for the forks on a Yamaha TY250 twinshock. These are the straight leg forks with 34mm diameter stanchions.

I have a ty250d project bike i'm working on, frame has had headstock steepened & peg mounts moved with modern pegs by previous rider. I've just gotten the parts to rebuild the foxshox(trials type) that were already fitted, had to reposition mounts to bring bike back to level. Now for the big question, are there any worthwhile mods that can be done to the forks while they're apart for seals, ie possibly remake damper rods in alloy with any suggested alterations to hole size & position. I know they'll never feel anything like a set of modern forks but if they can be improved why shouldn't i do it?

I posted this in the montesa forum but i should have posted it here, Hi, can you change the kickstart shaft without splitting the engine? silly question as i split a 349 a few months ago and i just cannot remember!! I have been offered a 1977 one with the splines stripped. cheers Dave

Hey folks, I am looking for magneto for armstrong hiro 250, or would any other magneto fit it as long as its ok for key & shaft? any info would be great thanks in advance.

Hello On an old 349 I'm picking up in a few days the rear shocks can be disassembled, but depsite that and some fresh oil there is no damping... No idea if they are original or not, but does anyone know anything about such things? I assume there are not many makes you can actually take apart easily. Thanks for any help! Steve

Just spotted this. Why oh why do this to a Bultaco 199B? link I'm stunned! Seeing as a nice 199B made 2500 gbp on evilbay recently I'm wondering what this will make now. Nowhere near the value of an unbutchered 340 I'm sure, but you can never tell. I guess he could started with just a frame and running gear as its not got the correct tank. Wayne...

Is it possible to restick magnets to magneto, do you need all the magnets for it to work? any info most welcome thanks.

Split the cases of my 1980 349, and was more than a little unhappy to find the gears badly corroded and not really serviceable (though they worked ok before the split) Is there any trials bike breakers in the UK? anyone know of anyone breaking a Mont? Thanks for any pointers.... Steve

Well it's happened to all of us at some time or other. Bought a pretty bike from somebody we thought we could trust only to find it's a total wreck once you delve beneath the pretty skin. This time it's my turn with my MAR. Only thing to do is bite the bullet and get stuff welded etc etc. Main problem that is really causing me concern is the crankcases are cracked around the gearbox drain plug which will have to be welded up. also the magneto cover looks more like a photo of frankenstien from the inside and has been welded, badly i hasten to add, more times than i've had fives. I know you can fit primary cases from all models including the Gripper because i know a …

Just assembling the crankcases on a '74 247 Cota and before I fit the clutch just want to make sure I haven't missed something. Do the crankcase bolts have O rings underneath the washers to stop air / oil escaping past the bolts? I can't recall seeing any when I took it apart although there were traces of silicon under the washers maybe, but I can't really remember, besides, there are usually traces of silicon sealer everywhere on old engines so doesn't necessarily mean anything. I'd never have thought myself but someone has mentioned there should perhaps be O rings fitted. Or is it just bolts, nuts and washers? I have a parts book but it only gives part numbers and n…

Hi All I have a Cota 123, complete except for the piston which has a broken skirt. I can get an original part but I'll have the hassle of posting it here. Does anyone know of another (Japanese?) piston that might match? Thanks in advance. David in Johannesburg

On my 349 I need to replace the gearbox bearings, two of which are in blind holes.... I have been told to support the case, behind the bearing, heat the case, and jam in the heads of a couple of large nails under the bearing to lever it out. Anyone got any further tips? Thanks Steve

Hi, anyone know the size of tapered bearings for a 1976/77 ty250 as my old cup races are getting a bit tired, cheers Dave

The manual says to torque the cylinder nuts on a Cota 348 from 14.5 to 18 ft lbs. My torque wrench starts at 20 ft lbs. Don't really want to have to buy another torque wrench [ another $50 ] ......... what do you guys do? Calculated *guess* when tightening? The cylinder head will be torqued 22 to 25 ft lbs, so I'm OK there.......

Hi All I have a ty250a with the piston stamped 25. Does anyone know if that is the first oversize? Also trying to remove the cylinder, one of the recessed bolts has been nicely rounded by a previous owner. Any ideas on how to get it off please? Thanks for any help you can give me.

I have been offered this nice looking garelli for a good price. The bike is 700kms from me, in italy. Trouble is, the kikstart doesnt work. i may need the gear, or shaft or how knows whatelse. Any sorces on spares out there? Thanks

How can I get the outer case of the old bearing out of the headstock? There is no 'edge' to knock against as the headstock tube flares out to accept the bearing, so the headstock tube is slightly smaller than the case. Is welding a piece of steel to the bearing case so that I can tap it out or pull it out the only way, or is there a special tool to do the job? Thanks, AMO

Can any one please tell me the differences between the Cota model 348 & 349. Was the engine basically the same, what was the actual capacity of each one. I seem to recall the drive chain was on different sides but then again I may be thinking of a different model Montesa altogether. Did they have electronic ignition, timeline of production, the good the bad and the b awful that sort of thing. atb TRF

Hi all I recently posted a message about the old TY I am restoring. As some of you may know I managed to find an original carb for it on ebay (TK) I cleaned it it all up and came up superb. Installed it and to my dissapointment the bike still has no whoomph. The number of the motor is 434-008250 so I am pretty certain it is an A model (You experts out there correct me if I am wrong) The bike starts first kick every time, seems to have some power down low, but when you hit the throttle, just wont rev right up. I suspect that I may need new rings ( they have not been changed in about 25 years and I also thought the timing could be out. What should the timing be set BT…