feetupfun

http://www.yamahaty.com/english/ty250en/technique250en.html use the info for TY250 type 516

If this is twinshock TY250 forks, the sliding contact areas in the fork sliders are integrally cast with the sliders ie they don't have removable bushings. The seals John Cane sells work well. Some others do not. Standard oil volume is fine. The first model TY250 oil volume is slightly different to BCDE model forks. Oil weight is personal taste. I find the standard forks work fine with 10 WT or 15 WT fork oil. Spme people use 5WT. The springs may have become shorter if they are originals. New aftermarket springs are available.

Scorpa 2T was Rotax water cooled motor then Yamaha TYZ motor then Sherco motor

In Australia we ride trials in river and creek beds. Some public land is protected from use by any motorised vehicle, but privately owned and privately leased land usually has few limitations relating to vehicle use

When Scorpas started coming out with the Yamaha 250 two stroke motor, I went to my local Yamaha shop and told them I would like to buy one from them but it had to come badged as a Yamaha like the one I had seen photos of in Japan - so I didn't get one

I would get the original casing repaired to reduce the potential for reassembly dramas If it is just the hole that the kickstart creates in the magneto casing, I would not pull the motor apart to fix it, but would fix it while it was apart if I had to pull the motor apart for some important reason

The Alpina/Frontera/Pursang front hub does look very similar to a Sherpa T front hub, but it has a larger diameter brake drum. The similar appearance is why I suggested it. It is hard to tell the difference visually unless both wheels are close together. I can arrange a photo showing this if you like. There is a slight weight penalty with the bigger brake drum. I have a couple of spare front Alpina wheels and brake plates I would be willing to sell if someone wants to make this change, but I am Australia so postage to overseas would not be cheap

yes I would think there is a pretty good chance of there being something unusual inside your 247 motor seriously - if you are using a different LH crank casing it would be a good idea to do a test-assembly of the gearbox with the correct centre gasket before you fit the crankshaft

or use an Alpina/Frontera hub

maybe a kid pushed them in through the oil filler hole

Have just checked the parts book and yes the standard pilot jet is #25

I suspect they were leaving the option open of making a trail riding kit for the TY175, as was made for the TY250A. The DT100/125/175 footpegs of that time mounted on that sort of spline. As with the TY250A, it would require a very long brake pedal

This homemade one works well and does not damage the edges of the gear teeth

Flat spots like that are usually because the pilot jet is partly or fully blocked. I will look up the standard size pilot when I get home to my workshop. My memory is saying #25

looks like pieces of a broken L section piston ring (should not be inside the primary drive casing)

maybe someone shortened the aluminium part of the barrell (where the base gasket goes) to achieve the right deck height with a different piston or conrod, but forgot to also shorten the liner. Unusual to have a tapered recess for the liner Very interesting problem you have there

Tubliss system if fitted has two valve stems

just thought of another possibility - maybe that rebore was done out-of-square

It is also possible that the crankshaft is not sitting in the middle of the engine, causing the conrod to rub when the cylinder is held square by tightening the cylinder bolts. I would also check that the crankshaft halves are not being squeezed inwards by incorrect shimming under the crank seal carriers.

You can get those orings from bearing shops I think that is the 525 model carby. It should be stamped 525 on the side of the body If it is 525 model Yamaha-Mikuni, the standard main jet is 240. I run 220 main at sea level and 200 main at 3000 feet ASL on that carby with a standard TY175 motor, reeds, air filter box and exhaust The standard pilot jet is usually fine at sea level and at 3000 feet, as is the standard needle clip position

To start with what carby is on it? There are two different design Yamaha-Mikuni carbies that came on TY175s and they have different jetting. A photo may be helpful with identification Yamaha TYs will work fine just by plugging the oil nozzle and running premix. Completely different concept to the TS185 You will need more oil in the premix than for your Beta because the TY is air-cooled. Once you can say what carby it is, then people can help you with jet sizes

They are two completely different processes, not usually done by the same company. The kickstart etc rechroming is called decorative chrome plating and is applied using electrolysis. Fork tubes are hard chromed, which is chrome metal applied (metal sprayed) at high temperature. Also fork tubes can be done semi-automatically while there is a lot of manual labour in doing decorative chrome work, especially replating something, hence why it is more expensive. That price for the decorative chroming does sound steep though from my experience

This is what the Aussie TY175JC looked like

in some countries they didn't sell a TY175 with this frame, but they did here and they were very popular

yes a standard steel TY175 tank should fit if the frame is unmodified