feetupfun

Thankyou to the people who have been helping me behind the scenes with the identification of the frame kit I recently bought from a riding friend from Mackay, Queensland, Australia The frame and swingarm has been identified as being mini-Whitehawk TY175 frame, and twelve are known to exist in the UK, no others known of yet in Australia. The bike was developed for riders too small for the full size Whitehawk TY175 and too big for the Whitehawk big-wheel TY80. The fuel tank manufacture origin is yet to be positively identified, but is likely to be a mini-majesty one-piece tank seat, that has been trimmed at the rear end to suit the Whitlock frame, and fitted with a bright orange/red seat and Yamaha tank stickers. The story of the purchase of it by my friend is as follows: The buyer knew of Sammy Miller highboy frames from his local trials scene in Central Queensland where there were a couple of Bultaco highboys. In 1988, at age 18, he ordered a Sammy Miller Catalogue, from an advert in a bike magazine. The catalog came in the mail. He phoned Sammy Miller's shop and spoke to Sammy and asked about the possibility of buying a highboy frame for his TY175. He was told that while the Bultaco and Honda highboy frames were made exclusively for his shop, they didn't make their own SM frame for the TY175, but that he could sell a frame suitable for the TY175 made by Mick Whitlock. My friend then ordered the frame kit, including the tank seen in my photos, front and rear gold anodised AKRONT rims, Betor Shocks, Renthal bars and a pair of UK-made trials riding pants (all from Sammy Miller). When the frame arrived, he noticed that there was no brake pedal (and no obvious way to fit one) and phoned the Sammy Miller shop to ask about it. A standard TY175 brake pedal arrived in the mail following that conversation. My friend had bought a TLR250 by that stage and lost interest in the frame kit for his TY175. The frame and parts were stored in my friend's shed in 1988 along with his TY175JC and I bought them from him about a month ago.

199 = red tank, black engine, black forks, silver frame

Yes you are right. More thinking needed. Ah heres a thought, maybe there is a dent in the slider?

I mean rust inside the tubes where the piston contacts the tube

If you have the frame, swingarm and forks assembled, just fit the wheels and measure how far the rims are out of position

Pete is it rusty in there? I had problems with getting some 348 forks apart when there was rust blisters on the inside surface of the tube

yes if you choose the right person it is possible to weld-repair magnesium castings. Yes it is a specialised job. My brother-in-law does this work regularly (he's in Australia though)

Hard to work out from what you have written, because there are only two MAR colour schemes and neither have any yellow or any black stripes.

The points should be touching with the flywheeloff so at least one problem is that the points are stuck open. I would replace any old-looking wiring because with vibration, the copper conductors work-harden and eventually break. What is that black thing with the green and yellow wires,a horn? ingition keyswitch? speedo?. The points cam follower and oil wiper look very dry. Have a look inside the flywheel at the points cam too and see if it looks OK. It needs to be smooth, clean and very lightly lubricated, or the points cam follower will get worn away very fast.

yes, undo the clamp bolts to reduce the chance of the thread jamming. It does make quite a difference

If you have contaminated the friction plates with friction modifier additive, it will not clean up by just changing the oil back to non-friction-modified. Having said that, I thought that including friction modifiers in car engine oils went out of favour years ago

Thanks oxboy. Sorry about the aluminium fuel tank thing. I don't know what made be think that. Your old bike leaning against the wall looks exactly like mine except for the tank. Your google search suggestion has also helped me to see how to modify a TY175 brake pedal to fit that frame. Also in the search results there were photos of a (full size) Whitehawk that shows that they have square top frame tubes, which someone was disputing. It also shows great detail about the frame design and in every shot the frame construction details are the same as on my frame.

I've done some assembly and posted comparison photos and dimensions of the bike here. It's a long forum string. The post date is 9 June 2012 http://www.trials.com.au/forum/viewtopic.php?f=16&t=4785&start=420

For external appearance, the closest crankcases are the DT175 A,B,C,D but the internals are different and so internal parts may or may not not be interchangable between motors eg crankshaft, gearbox, clutch. From E model on, the TY cylinder and flywheel cover wont fit. Yes the kickstart return stop can slip on the kickstart shaft, allowing the shaft to return too far. This allows the head of the screw on the spline clamp on the kickstart knuckle to hit the casing, punching a hole.

Rocking horse poo now on ebay http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=251081315734

yes it was - sorry about that- have just emptied it out

Thanks everyone for the info. Much appreciated. I now plan to put it together and do some size and geometry comparisons with a standard TY175 and will post up what I find.

The John Cane one fits neatly up in the frame under the fuel tank and works well. The electrix one also works well, but requires the coil/black box to be fitted behind the plastic sidecover and supporting it requires some thought and ingenuity to achieve. It also means the HT lead is extremely long.

No-Toil dries out and becomes not-so-sticky much quicker than normal filter oils (in my climate anyway)

It's false economy to only change the rollers. The pin and rod will also be worn if the rollers are worn, even if they look OK and someone will be having to do the whole job over again shortly. yes head gaskets are expensive, but you don't have to change the head gasket if you take the cylinder off with the head intact

maybe the points are not working? maybe the stator coil insulation has broken down? Maybe the stator coil is open circuit? maybe the HT coil has failed? maybe the killswitch wiring is shorting to earth?

why would you ever want to change just the needles and cage?

The motor ID number (M4) says 1963-1965 Sherpa N 200cc, but the cylinder head and the rest of the bike looks like M16 (MK2 Matador 250cc 1965-1967). The MK2 Matador was developed from the Sherpa N, so this bike may be a very early Mk 2 Matador. I suggest you fit an air filter before starting the motor, and get ready to stop it quickly if any of the motor bearings get noisy

Before there was "air filter" oil people used car engine oil or two stroke premix oil on foam air filters. It will work fine if you oil the filter the night before, or on the day of the ride. Not long after that though it migrates downwards, making a bit of a mess in the filter casing, and leaving the top section dry. I use a proper air filter oil mainly so I can service the air filter well in advance of the ride when I have the time available.

A riding friend had a tubeless rear rim fitted recently no problems to his TY250D (and also one to his Bultaco M198). I don't know if the rims came undrilled, or if the angle can be changed, or if the angle was fine as it came, but I do know his wheels are fine. The rims used are the type with the rubber wedge seal ring, which means that the spoke length will be different to standard Yamaha spokes. If the spoke angle is wrong the spokes have a curve in them that looks terrible and are more prone to breakage than if the nipples are at the right angle.