feetupfun

Once I changed the clutch on my son's TXT Boy 50 to two springs, the gearing became perfect. Previously (with all four springs) it had to rev so high for the chutch to engage that it was going too fast for riding in sections. My son is about 24kg. Maybe a much heavier rider might need different gearing on hills.

just because it is listed at 6000 pounds does not mean that someone is prepared to buy it at that price

About the routing of the cable, I have those same mudguard mounts on two of my Yamahas and find that routing the cable between the flat section of the mount and the tyre gives a smoother run for the cable with a Yamaha cable. On one of those bikes I have slightly straightened the bend in the cable tube to make it fit even better.

Yes that is a standard Yamaha cable There can be sometimes a problem with the plastic sleeve inside that bent steel tube where the plastic sleeve sticks to the cable and creates a lot of friction. I usually remove that plastic liner to avoid the problem. If you are seeing some straightening of the bent steel tube, that just means that you are putting a lot of tension on the cable inner. It is not a problem in itself. If your cable is more than afew years old, the brakes will work noticably better with a new one. To diagnose your braking problem better I suggest you check: How far the cam is rotating from neutral before the shoes touch the drum How well the curvature of the shoe surface matches the surface of the drum

All the adjustable caps do is save the labour required to take the caps off to adjust the spring preload. Standard Yamaha springs are progressive rate and work fine for me at 93kg. I even use the standard Yamaha preload setting. I do use 20wt oil set to 125mm from the top which probably makes them a bit stiffer at the end of the stroke compared with using the standard oil quantity. I like the standard TY250 springs so much I also use them in my KT250 forks and my Cota 348 forks The TY250 forks do have odd damping though - if you jump off another similar age bike that has good fork damping (like an OSSA MAR), then the Yamaha fork action does feel a bit strange. It doesn't seem to cause any problems riding with TY250 forks, but they do feel different.

Alan turning is not affected because your knees are still above the seat, but lowering the footpegs does reduce the clearance under your bum so when you unweight the rear end of the bike there is a higher chance that the seat or rear guard will hit your tailbone. Most commonly noticed when crossing big logs or jumping up an obstacle. Not a problem for people with long legs but I am 5'10" in your measurements and find that a couple of times I have hit my tailbone on the rear guard on my TY250 twinshock with lowered pegs when doing energetic unweighting of the rear end of the bike.

John I cant see any footpeg kits for Tys on the tytrials.co.uk website. What kits are you looking at? David

I reckon you should keep that yzee and just sell the triumph. In ten years time you will greatly enjoy taking it for a blat - I know I love still having my old MXer - riping up some grass at home once a year with it, leaving black lines on the driveway, making a bit of noise

Steve have you priced one from John Cane in the UK? I find it to be economical to buy from John compared with my local (Australian) Yamaha shop for TY175 kickstart assemblies.

I have used two different brands of brushing epoxy inside three or four Spanish trials bike tanks and they both worked fine. I can't remember the name of the first lot, but the last lot was called "West System 105 Epoxy Resin" and I bought it from a local boat repair shop. I would think that any 2-pack brushing epoxy would be modern-petrol-proof. You can look up the properties of epoxy resin on the internet if you want to check.

The TY80 kickstart will probably work fine if you can work out how to ride the bike without a right hand footpeg

Hekto from that photo it is very hard to see what shockies they are. Please take a close-up photo of one of the shockies

Whichever engine you use, the crankcase will need to be machined out to suit the bigger sleeve.

To fix only the immediate problem: Clean out tank with acetone Mask tap thread with plasticene Mix up brushing grade epoxy resin Tip in enough to seal the area around the tap hole Move tank around enough to make sure the problem area gets a coating Allow to cure To protect the tank from modern petrol and fix the crack: Clean out tank with acetone Mask vent hole and tap hole to prevent blockage Mix up 300-500ml brushing grade epoxy resin Tip in and rotate tank until whole inside surface is coated Allow excess to drain out the filler hole as it cures

Early DT175 motor is the same cylinder stud arrangement as TY175 motor. Late model DT175 has different cylinder stud arrangement but I have not yet measured up how big a sleeve can be fitted. Rayer big bore cylinder photos I have seen look like a late model DT175 cylinder but modified to suit the TY175/early DT175 stud pattern.

and the other wire from the kill switch goes to earth (usually at the coil mount)

I've had success using contact cement to attach those plastic badges.

The 72mm and 72.5mm piston kits for the Blaster look very much like what went into my engine but I can't be sure they are the same. My piston uses Wiseco rings also. The pin size looks right in the photos, but if you have a doubt, why not just ask the seller what size the pin is? - and check the other important aspects of a piston swap like ring location pin positions, height from gudgeon pin to top edge and gudgeon pin to rear edge of skirt. Beware while those piston kits and the sleeve look well priced, the main cost components in the job will be the welding and machining. Cylinder head - weld up head nut holes and redrill to 8mm - machine head surface flat - machine combustion chamber to suit bore diameter - machine combustion chamber to provide correct squish and correct compression ratio. Make custom head gasket to suit bigger diameter bore. Make or find longer cylinder studs to enable use of plain hex cylinder head nuts. My studs and nuts are from a Maico MX engine. Machine throat of crankcases to suit OD of bigger sleeve (requires complete disassembly of motor) Machine out old sleeve and prepare cylinder for new sleeve Cut port holes (undersize)in GS1000 sleeve Machine GS1000 sleeve OD to provide interference fit in cylinder Fit sleeve to cylinder Take ports out to match cylinder with porting tools Bore sleeve to suit piston Make custom cylinder base gasket Other possible pistons to consider are KDX220 and TY250 twinshock. Don't know much about the KDX220 but the TY250 piston requires the gudgeon pin holes to be bushed smaller but being only 70mm will have a far less risky sleeve thickness than mine.

Hi Steve The steering on that TY175 with the frame mods is as good as I have ever felt on a twinshock, so I have no desire to change the steering angle. I suspect that the fore-aft weight balance of the bike+rider also has a lot to do with the steering as well as the steering geometry. Yes I do ride (other people's) moderns now and then and find that there are so many differences to a twinshock in how they are to ride, that I have trouble riding anywhere near the same standard as I can on a twinshock, so can't really comment on differences in the steering. I think that the TY175 with the frame mods has better ergonomics than the standard TY175 because the handlebars are now higher and further forwards, which gives more room to move around on the bike, and the stance is slightly more upright. I am only average size but feel a bit cramped on the standard frame bike. A smaller rider may not find those changes to be a benefit. The TY175 with the YZ125 clutch cover has a motor which has the bottom end from a 3H8 prefix motor (DT175E I think). The motor came with that YZ125 clutch cover. I haven't tried to fit the YZ125 cover to a TY175 motor. I'm only thinking it is a cover from a YZ125 because it looks the same to me as covers on late 1970s YZ125 (DEF) and IT175 (DEF), which lines up age-wise with the DT175E. Maybe the earlier YZ125 motors (ABCX models) had slightly different clutch covers that will fit the TY175. An easy way to check these things is to look up the part numbers for the clutch cover gaskets for the different models. I will take a photo of the longer TY175 brake link and to avoid external photo hosting, will probably post it on the Aussie trials website.

Yes as Andy.T said, I replaced the rubber elements in my TY175B cush drive in the late 1970s when I noticed there was a bit of slack there and thought it might affect the way the power was delivered. It took quite a bit of work, having to make new rivets and cush elements. I didn't notice any change in the way the motor felt and reckon I just wasted my time by working on it. I still ride that same bike and the clutch basket cush drive is still going fine. Of course if for some reason the rubber elements were allowing metal-to-metal contact they should be replaced.

The sleeve was made from a GS1000 sleeve The piston was from a kit that converted the DT200/WR200 to 230cc

corrosion in the cooling circuit

Australian design regulations for road-registerable motor bikes require the side stand to be self-retracting. I assume it is the same in many other countries. Aparrently there were a significant number of deaths and injuries around the world attributable to people riding (road bikes) with the side stand still down so all road-registerable bikes require it. Until now I didn't realise it was a "feature" on new trials bikes. It is very unusual to road-register trials bikes here so the trials bike importers probably nobble this "feature" before we see them.

On the same issue, I suspect that fitting a wider rim will make a competition trials tyre work less well on trials terrain than it would on the standard width rim If it was being used on a Dirt Track racing bike (a slider) there might be an improvement by fitting a wider rim.

The increased width of the bigger rim will be no problem as far as clearance goes. I know this because I fitted my M138 Alpina with a Pursang rear wheel (which have a much wider rim than Alpinas and Sherpa Ts come with)and it made no difference to the clearance to the swingarm, exhaust and chain. The width of the tyre is the critical dimension - not the rim.