feetupfun

It was to avoid scraping one's boot edge on things, which (once upon a time) used to earn the rider a point. I'm used to the standard peg position on all my 1970s bikes and after trying out lower pegs on one of my TY250s, do not want to lower the pegs on any of them.

Depending on how long your legs are, lower pegs mean you may get hit in the bum more often by the rear frame loop when unweighting on obstacles. I lowered the pegs on one of my TY250s a little bit more than the SM kit pegs and while the bike was easier to balance, it made it a bit more restrictive to move about on the bike (I am 174cm - 5' 10")

If you have the front hub as used on most 247s and all 348s, then yes the front spokes made for TY175/250 front wheel will fit. Would you like a photo showing my 348 front wheel recently respoked with genuine TY spokes?

also do you mean the end that goes through the cover? or the end that turns in the gearbox casing? I found that I needed to rebush both on one engine,

The tank looks long because the top shock mount and associated frame joint is further forward then standard

No they are a very good clutch if working properly Things to check: edges of basket fingers need to be completely smooth not ridged steel plates need to have a rough finish (not polished smooth) cam surface smooth end of pushrod smooth newish friction plates (originals would have lost their frictional properties by now) suitable oil in good condition

The shape and location of the AB and DE airboxes is the same, but the lids are slightly different because the CD models breathe through a slot in the lid. Nothing that will cause a problem with the seat screws.

It's not raining so I can get to my shed and take photos These are photos of later model TY250 frames showing the seat mounting lugs. The photo showing the RH side of a frame is of a D model and the one showing the LH side seat mount is of a C model. The inner surfaces of the lugs are flush with the inner edges of the frame tubing

yes but you will need to add seat mounting lugs to the A model frame. I can do a photo if you want

I'd like to use Greg's top picture to show people what normal 1970s handlebars look like when they tell me that mine look like ape hangers

It looks like a YZ or IT Yamaha to me. See if you can get a photo that shows more of shape of the hub (between the spoke flanges) and another that shows the backing plate.

Bondy if you post photos of the rear wheel someone might be able to tell you wnat bike it is from so you can easily source a sprocket

Very nice job. I especially like the rubber slipper for the lower chain run

Yes

Unless the nut rubs on the cover you don't need to do anything as there is no problem

Old geezers can have problems getting their boot high enough to kick start some twinshocks. I can get my boot high enough even for my Cota 348, but then it takes such a big hummmph to kick it, it seems to be the hardest part of riding a trial on it. I think JonV8's electric start twinshock has a lot of merit for that reason. As far as standard bikes go, my least tiring bike to kick start and compete on is my M49 (250cc) Bultaco. It is very relaxing to ride and I guess because it is so old, it has somehow learned how to ride.

maybe that one has been turned down - it might explain why it is so clean too

This might sound strange but have you tried the damping with them up the other way? Some shocks have damping that only works with the shock one way up

The standard nut does stick out past the flywheel, but yours appears to be sticking out a bit more than normal. It might be sometning as simple as there being too many washers behind it, or the nut may be longer than the original, or it may be standard and your photo makes it hard to judge exactly how far it is sticking out. It has to stick out somewhat, or you wouldn't be able to get a standard-walled socket on the hex. The flywheel appears to be much better-looking than the usual Bultaco flywheels I see which has me wondering if it is a non-original flywheel

I just thought of something else. Some people just call them "triples", which can get mixed up with another "triples" (three jumps in a row on an MX track)

Despite being a colonial, I don't know where the term "triple trees" comes from. I call them "triple clamps" because each "yoke" has three clamps (for clamping the two fork tubes and the one steering stem) I find the alternate spelling often used for "yokes" quite amusing ("yolks")

Roughness of the race will definitely cause you grief. I hope you know for about $50 you can buy a full set of tapered needle roller bearings, or if you are an originality-is-important type person, you can still buy the standard Yamaha races and use loose balls for about $80.

Yes it works but it is not by flooding the engine. It is by the fuel moving to the "top" of the float bowl, away from where the jets normall suck it from - so it just instantly runs out of fuel

The reason it gets tighter when you fit the top bolt is that there is a small amount of axial clearance in the threads of the stem and the castellated nut, so when you tighten the top bolt, the castellated nut moves downwards slightly, which tightens the clearance on the ball races. I find I have to set the castellated nut slightly loose so that when I tighten the top bolt it ends up perfect. Sometimes it takes a couple of goes to get it right. I suggest you leave the stem clamp bolt and the tube clamp bolts on the top triple clamp loose until you have got the top bolt tight and the castellated nut set in the right spot.

Even if a carb does not ice up, in conditions of high Relative Humidity, the water that condenses out of the air as it goes through the venturi can cause havoc. Have even seen problems with this in the balmy climes here when riding in just after a summer thunderstorm.