feetupfun

This is about your 2mm ring gap comment If the old piston has a ring end setup like the MAR piston, the standard ring end gap is huge as measured by putting the ring in the bore, because the locating pin separates the ends of the ring while most bikes the pin sits within a recess in the ends of the ring.

or 3 to 7 of our kg things

I took it that he meant that when people fit stiffer forks springs to their KT to make the suspension work better, it makes the steering slower than with the standard woeful springs because the front doesn't compress as much. Doesn't mean I agree with him, just what I thought he was trying to say.

All you have to do is compare the lengths of the TY175 and TY250 forks to see where to run the Ty250 forks. From memory the TY250 forks are about 20mm shorter overall.

The top two look like they have a rear disc brake that uses the sprocket as the brake disc

This subject has been done to death previously http://www.trialscentral.com/forums/index....p;hl=puller+348

People have been saying that about bike/car/whatever development for 100 years. Of course they will keep getting better and manufacturing costs will keep coming down. Trials bike will never be like Concorde, because they are developed to satisfy a real demand.

1 Yes just cut the wire and leave it there 2 I just run a short wire to the condenser from the LT side of the HT coil and have a bullet connector at about carby position that is easy to get to to disconnect the points from everything else and easy to connect the light bulb wire to for static timing setting (don't have to take the tank off) 3 Any condenser from a car that has points/coil ignition is fine. They are getting harder to find nowadays.

That plate also allows the ignition to be removed and replaced to inspect or replace the crank seal, without having to reset the points when reassembling.

That plate allows different ignition systems to be fitted to a generic inner case casting ie a trailbike or MX bike that shares the same LH motor casting with the TY250A may have a points ignition with mechanical advance, or it might have an internal rotor elctronic ignition.

Taking out the lighting coil will not affect the ignition system. If you are talking about the stator backing plate, then it just a slight issue with the english translation from Japanese. What do you reckon it should be called?

Alan yes it is fine to do that on a TY. The condenser can't tell what brand bike it is on. Regards David

What makes you think you will get unconflicting answers about premix ratios on this forum?

Yes you did miss something. They were sold in Europe and are something of a cult bike - as are TY50s. We didn't get any TY125s here either.

Its good they eventually ditched the tubes. Thanks Tim I wasn't sure which models had them.

Yes probably piston slap but may also be the primary drive gears if the crank end is running out. If the noise is from the primary gears the noise will be the same under most conditions while piston slap will sound worst while on closed throttle overrun from highish RPM. Spring loaded tensioners seem to be more popular than the chain guides. Theres a neat one available that mounts on the gearbox case. Have a look at what other riders use. Museum standard bikes will have the tube guides while many ride bikes have a tensioner.

Sorry no photo, but a riding buddy of mine used the same system for transporting his trials bike from Rockhampton (Queeensland) to Brisbane (Queensland) (650km each way) for trials competitions through the late 1990s. He used a Yamaha Super Tenere XTZ660 and had it set up well with communications (CB radio, phone and stereo).

I sometimes suggest to young people that they should get a job and earn squillions of dollars using their knowledge while they still know everything (before they get older and forget it all)

Replicas of the standard mounts but made in stainless steel are available from Fred and Debs KT Parts in New Zealand (and lots of other good stuff for KTs)

The reason why the condenser may be the problem is that you are checking the ignition timing by measuring when the points open, while the timing of the spark at the plug can be quite different to when the points open if the condenser is not working. Reasons for why the motor may not be sucking enough air are most commonly the rubber tube between the carby and barrel gets a split, crankshaft seals leaking or blown cylinder base gasket.

Is the fuel in the float bowl getting mixed with the incoming air? You haven't said if the plug is getting wet or not. If the plug isn't getting wet by you trying to start it, then the fuel is not getting mixed with the incoming air. You also didn't mention checking the pilot air passage for a blockage (old filter foam maybe).

Here is a brochure gallery that may help you ID your 349 http://www.southwestmontesa.com/gallery.html

I agree with mattylad about the monoshock OSSA and I would also allow Mick Andrew's 1973 works cantilever monoshock trials bike in Twinshock class, on the same basis. The Yamaha cantilever rear end was obviously found wanting because the frame was later modified to a twinshock rear end. Like the Yamaha works bike, the OSSA cantilever suspension was a design dead end. Both would be quite inferior to most of the twinshock bikes commonly seen in competition nowadays - and should be warmly welcomed into twinshock competition.

I see the bike you are talking about now. We didn't get that model here but it looks just like the XT350 we did get till about 1984. Yes the XT400 motor is way too tall to fit in the TY250 frame.