Basket Cases

[Greg Harding]

Hi Everyone,

Have been a bit busy to work on the KT, however I have been sourcing parts, still waiting for the local dealer as the inlet parts and sprocket nut are on backorder.

Fred and Deb's KT in New Zealand are sending over all of the parts for the top end, gaskets and seals and an ignition black box.

TY Trials in the UK are sending me a 12T 520 sprocket.

So I am now looking forward at potential problems for reassembly. The forks look pretty good in the photo (have hand linished them), but the chrome is worn through in places and some rust pitts are quite deep. The sliders are very worn in the seal area, especially on the brake side, even with good chrome I don't see them sealing! At some stage, the headset has been very loose and the balls have escaped and worn into the spindle!

Can anyone help me with forks or a spindle? Please!

[Bully fanatic]

Hello Greg. To me it looks like those triple clamps have Timken bearings on them so you should get new bearing cups when you buy new Timken bearings from a good bearing shop. If it has worn the steering shaft you should be able to weld it up and grind/ file it smooth afterwoods. As long as the bearing race sits where it should it should be fine. As for the forks have you tried hunting around the wreckers for fork stanchions off another model the same size. Usually the Japs used forks on a few models in the same years so something else would have to fit. Good Luck. Graham.

[Greg Harding]

Hi Everyone,

Graham, the bottom bearing is a tapered roller bearing, KOYO HI-CAP 30205 JAPAN to be exact and loose balls at the top. Welding and finishing is not the problem, controlling the distortion so both bearings rotate on the same axis is what worries me. Looks like David has a spare spindle and swapping it would be my first choice.

Previously, I had an extensive search with Vernier Calipers in hand at the local bike wreckers looking for 34mm TY250 fork legs. They are not a common size with 33mm (TL250) and other Hondas fairly common and 35mm very common, even some Spanish bikes you might recognize. KT's are 34mm and longer than TY250, the only other bike that I found that used 34mm was Yamaha RD series which are too short for a KT. Plus the sliders I have are badly worn in the seal area leaving me scratching my head.

[David Lahey]

Greg I remember that bottom bearing well from when I got my KT250 basket case about 12 years ago. The original bearing was very rusted. At the local bearing shop they had the correct size tapered needle roller bearing with no seal or shield for $16, or I could get the version with inbuilt seal for $85. I decided to get the $16 one and avoid hosing that part of the bike - 12 years so far and no problems.
After seeing the photo of the gouged steering stem I realised I had seen similar before. It is amazing that people can ride a bike with what must be quite stiff steering.
I'm pretty sure that 34mm was a size used in the larger Yamaha and Suzuki trail and MX bikes of the early 1970s. They might have been discarded by now from wreckers because it would be quite rare to find any that were not rusted by now. I asked about 30mm tubes at a local wrecker (for TY175) and was told they had thrown away all their 1970s and 1980s 80cc MX stuff (30mm forks included) because there was no market for it.

[FM350]

If you have 34mm forks fitted, it would be pretty easy to get yokes bored to accept easily available and more modern 35mm fork tubes. Worn steering stem can be repaired by TIG brazing the damaged area, and machining back to size in a lathe. If there is any space at the bottom of the head stock, its very easy to turn up an aluminum spacer, with a groove to accept an O-ring, that will seal the bearing pretty effectively.

[JC1]

Greg, David is correct about 34mm tubes being widely used by Yam & Suz thro the 70s, esp on their DT/MX TS/TM models, but the VMX boys have probably scoured the wreckers for them by now. DT tubes come in diff lengths & all are longer than TY ones so could be right for the KT - if you can find some

[Tim Stone]

Unsure if it is any help, but Ross at Tiaro Bike wreckers (www.tiaromotorcyclewreckers.com) had a TY250 front end about 6 months ago when I was there. Complete with triple clamps. More than likely they will need re chroming but everything was there, triple clamps forks even front wheel still attached give him a call 07 41292771.

[Greg Harding]

Hi Everyone,

FM350, have looked at boring/reaming sliders and tripple clamps. The problem with boring the sliders is holding in a lathe, yes it could be held in a 4 jaw chuck and spin on centre, but getting it to run true to it's axis and not boring off centre at the bottom is a bit more difficult. So then I thought about reaming them, I do have an adjustable reamer 30 to 38mm, only need to go from 34 to 35mm. The reamer would be pretty much self aligning, but the problem is it won't go to the bottom, I could open the bottom out with a flapdisc on an extension and it wouldn't matter if a little big at the bottom.

JC1, there was a large collection of forks at the local wreckers and I think you are right about them already being raided or as David said rusted and discarded.

Tim, already have a collection of TY250 forks, tripple clamps and wheels, going that way creates a clearance issue and the chrome legs are too short for the KT sliders.

The Guru from Gladstone has bailed me out of trouble again with a set of KT forks and a spindle. David was a little concerned about one leg weeping even with new seals. To me, it will fit in with the rest of my bikes and be heaps good enough for my humble requirements.

On to the next problem, the back wheel with 3 broken spokes and the rest pretty rusty.

Again David has supplied me with painted spokes all neatly packaged,

so I will beadblast and paint the hub.

[FM350]

There is no need to machine the sliders, as you use the stanchions and sliders from bike with 35mm forks. Machining the yokes is merely a matter of setting them up on a mill, and enlarging to 35mm with a boring head. Not a great idea to use straight axle forks though, so you would need to find a set of 35mm with leading axle. If you could find them used forks from a 305/245/205 Fantic would work almost as well as modern 38mm as these have cartridge damping, and will transform front end.

[Jon V8]

I had a quick ride around on Shelly's KT on sunday at the end of the Golden Valley trial.Its not quite finished yet,needing some rear shocks and a bit of final tweaking.The pictures in the link may give some ideas to try.I must say it steered very well and the engine is a real treat.
http://www.r2wtrials.co.uk/html_files/kt250.html