feetupfun

I'm not surprised hearing that the steering geometry of the KT is similar to a mid 70s Bultaco. I would describe the overall feel of the KT as being like a slightly top-heavy mid-1970s 238cc Sherpa T and the steering behaviour in very tight turns is virtually identical. The Sherpa steers better in a straight line over obstacles though. Did you try the Kawasaki shop for spokes? They are good value and you know they are going to fit without any issues.

Heres mine at a trial last weekend

Michael I've had mine for about 5 years and have done lots of minor tweaking to try and make it as easy to ride as a TY250 and reckon what I've done has taken it to about 90% of being as good for trials competition. The big weakness for the KT compared with the TY250 is in tight turns. It will turn tight but you have to manage your body position, the clutch and rear brake very closely to do a tight turn that you wouldn't even have to think about on a TY250. I see the strengths of the KT as: Ergonomics - there is plenty of room to move around and the kickstart is a dream to use compared with most trials bikes. Ground clearance is better than the TY250. Clutch is more positive in engagement than most of the Spanish bikes (is similar to TY250) Great ergos for sitting down riding. Setup: Wiseco CR/MT250 piston Standard porting, carby, exhaust, airbox, timing, cylinder head shape TY250D fork springs, 20WT oil 125mm from top, non-vented fork caps (from TY250) 360mm Falcon shocks with 50lb/in springs Standard rubber swingarm bush arrangement Standard frame (and no tube damage under the motor yet) Standard footpeg position but with grippy pegs Increased leverage for clutch. New plates and springs (standard). Modern low friction cable. Standard flywheel weight Front drum machined and high friction oversize shoes machined to fit the drum perfectly. Modern low friction cable. Standard rims (and no cracks yet) Very low gearing. 12T or 13T front and standard size rear (flat with spacer). 428 chain. Replica KT250 handlebars (much higher and a bit wider than 6" Renthals) Standard fuel tank. Michelin tyres. David Lahey

I find it very hard to imagine anyone wanting extra flywheel mass on top of what Yamaha fitted to the TY250B,C,D or E motors. The first model TY250 had a slightly lighter flywheel than the later models and some people might find that model needed a bit more. Micky are you talking about 250cc Majesty motors or 320cc Majesty motors? I've tried a range of flywheel weights on my 250cc TY250 motors and have found that with the band removed, it feels great to start with - nice and peppy for jumping obstacles with no runup, but suffers in the traction stakes in slippery going and tends to stall easily amongst dry rocks. With the standard size band fitted, the motor is on the slow side for most riding but very good in slippery stuff. After 3 tries machining a bit off at a time, I've ended up using the band but with about 1/3 of the width of the band machined off (on stock standard D and B model motors both in very good condition).

Sorry mate I can't understand what you mean

Michael 5mm structural aluminium would be OK if you include lots of stiffening either creases of ribs but they usually end up looking terrible. I reckon 6mm structural is the go. The rubber insert helps a lot with avoiding the plate being bent and also quietens the plate down nicely. Even 6mm structural will eventually bend with use without an insert.

If you seriously want help I suggest you have another go at explaining what the problem is.

Thanks Woody. How far back do you reckon the pegs are from standard?

I love a challenge It looks like a M80. I first thought it was a late series M49 but the footpeg mounts are welded to the frame. Homerlite aluminium seat/tank to meet rego requirements in the UK Sammy Miller front guard mounting because the standard ones wreck the guards Aftermarket alloy mudguards - no idea Low rise handlebars - no idea Ty twinshock headlight and mounts - no idea Non standard speedo mounted up high - to meet local rego requirements Sammy Miller chain guard - no idea

Swooshdave, I'm not just off with the OSSA people, I'm a full-on 1970s twinshock trials nut who has no particlular affiliation with any brand except for not liking Hondas. Yes I'm fixing up my OSSA to make it good enough to ride in competition and look nice, making my M49 nicer to ride, fettling my KT to the point where I'm happy to compete on it, machining the front brake drums on my four twinshock Yamahas (3 TYs and a Majesty), restoring a Bultaco M198 from a basket case and restoring a M138 Alpina also from a basket case. I've been full-on fixing up 1970s twinshock trials bikes since 1995 with a goal of answering a whole swag of questions I have had for a long time about them by owning and riding them back to back. David Lahey

Tim it was me David Lahey who put the link up and no it isn't on trials.com.au yet. Its relatively close (six hours drive) to where I live. If I didn't already have the red 198 I'm currently fixing up I would have driven there and offered enough to buy it on the spot this weekend. 198s don't come up for sale very often around here and that one appears to be in quite amazingly original condition. If someone from overseas wants to buy it (especially kiwis) I can pick it up and mind it for you till you can arrange the transport. David

Thanks Woody I reckon I know what you mean about the L brackets. I'll ask you again in a while when you are happy with the location then I'll make nice looking brackets using what you reckon is the best position. I'm pretty keen to get rid of the original brake pedal too. It really is a monstrosity and reminds me of what was on 1960s Japanese commuter bikes. David

Suggest you have a look for yourself. I wouldn't describe it as tricked up. More like restored using some non-standard parts. You can see the bike advertised on John Cane's website at least it was last time I looked a few days ago.

Woody I have an early type M49 (M49-00100) and am considering relocating the footpegs to make it a bit easier on the body to ride. I'm guessing from your remark about your bike having to be entered in the specials class because it has modern footpegs that you have also moved the footpegs. If you have, please advise what you did with the footpeg location and the footbrake arrangement and what you think of the changes. Thanks David Lahey

Michael I am enough of a perfectionist to have done that sort of experiment you described with moving the pieces of lead around to see if it was noticable. I had solid aluminium handlebars on a standard TY250 twinshock and thought it was not quite as nice in some types of turns as my other TY250s which had tubular aluminium handlebars - particularly turns where rapid bar movement was required. My experiment was to swap the bars between the bikes so a different TY250 had the solid bars. Both sets of bars had the same shape and were the same width. No change to tyre pressures or fuel tank contents or anything else except the handlebars. Yes it made the previously very "nice" steering TY250 noticably harder work to do turns that alternated quickly from one extreme of steering angle to the other. Since then I have been an advocate for minimising mass in the steering particularly at the ends of the bars and the wheel rims/tyres. I find the steering geometry of both my standard TY250s and my Godden Majesty to be quite wonderful compared with the other twinshocks I use in competition (OSSA MAR, KT250, Cota 348) for the type of riding we do here which is dry, tight and with plenty of traction. I suspect that if we rode mainly wet, mossy boulder strewn creek beds, that other bikes like the later model Sherpas might be just as as good or even better. I find Sherpa T steering to be as sublimely pleasurable in those conditions as the Yamaha 250s are sublimely pleasurable in the opposite conditions. For people with TY twinshocks, did you know that the D model TY250 rims are lighter than the A and B model rims and so provide slightly less moment of inertia as Michael has explained. Not sure about C model rims.

Here is a rather more complete 198 for sale http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...A:IT&ih=003

You have just got the exhaust system hot enough to start cleaning itself out. Thats what makes the smoke. You can't "blow" rings on a 2 stroke. You can sieze 2 stroke rings or wear them out but neither causes smoking. You probably need to do a few more fast runs on you bike to clean it out fully or have the engine and exhaust decoked. Anything that requires the throttle well open for a minute or so will usually do the trick. Very long steep climbs are what I use. The strange uneven running could be anything from using old fuel to running out of fuel to a crankcase air leak to a partially blocked pilot jet. More info on the "backfiring" needed. Very rare for such a bike to backfire in use. I think you need a better description of what it does and how you are riding when it happens. It's not uncommon for 2 stroke trials bikes to only fire every 5 to 10 strokes on throttle-closed overrun if the revs are up a bit. Is that what you are getting?

Acetone addition not recommended for fibreglass fuel tanks

Hi YamaDan Pardon my ignorance of world place names but where is The Oc and is there good weather for trials riding?

I'd have to agree with Majestyman340 on that if you want to ride it in competition the Bultaco is the go or maybe the very last model Cota 349 (which are as rare as hen's teeth). If you only want to look at it then it's a very personal thing. Of those you have listed I only find the Bultaco attractive-looking. The others have styling that looks too modern (or too weird in the case of the OSSA Gripper).

Pirelli (I think model is MT43) are similar to your old Barums. Barum is called MITAS nowadays. MITAS also make trials tyres that wear slower than the Michelin/Dunlop/IRC competition-only tyres but probably not as long wearing as the Pirellis.

The IRC tube type rear is great for twinshock use. The only difference in performance from Michelin tube rear is the IRC needs a slightly higher pressure than a Michelin to feel the same ie it is a bit more flexible in the carcass. The IRC is especially good because it is the only tube type rear that is easy to get a hold of here.

OSSA MAR handlebar clamp screws are M7 x 1.0 x 55 long (from end of screw to underside of head) and the thread is 20mm long Dave This OSSA person is the same person who fixed up their M49 at about the same time as you did yours. David Lahey

The first model Majesty made for the TY175 motor did use a modified Yamaha TY175 frame. The only frame mod though was to relocate the top shockie mount. The frame tubes under the motor were left untouched. Later Majestys with purpose built frames made for the TY175 motor had no frame tubes under the motor.

Dave, OSSA MAR handlebar clamp screws are M7 x 1.0 hex socket head. I will check later tonight re the length. David