help needed urgent please

[phill.c]

well i was riding to work this morning, i was in forth gear and revs died on me then the back wheel locked up with the clutch in, but i managed to keep it up. after that it wouldn't start straight away and a few times it did then just died again. i managed to get it going and get to work but it died a few times on the way. its a mtx 125 2 stroke.
does anyone know what the problem could be?
cheers for any help

[Frost]

Either no fuel, or no 2 stroke oil

The fact that the rear wheel lovked suggests that the engine seized due to lack of 2 stroke oil

[flat spot]

It surprises me that it locked up with the clutch in. If it did that then it has to be something jamming the gearbox which is unlikely at best.
Do you mean it locked up and you pulled the clutch in and managed to control it?

If so it sounds like it could be nipping up. Have you checked the 2stroke oil level? If it's there, is it getting through?

Have you got plenty of coolant (I'm assuming it's water cooled) with anti freeze in it?

Does it have a temp guage and what was it on when it happened?

Yes, I forgot the obvious one fuel. Has it got enough in? Check the tap isn't clogged up with c**p.

[phill.c]

well it locked up and i pulled the clutch it but it kept locked for abit till i stopped then it died, i put it in natural then wheel moved. i know it has fuel and the temp gauge was on half not really hot.
ive got a feeling it could be the oil
but i can't get to it with out an alan key any ideas of how to get it off?
this days just going to be a sh!t one i can tell.
cheers for the help tho

[Kickstart]

Hi

As mentioned, if it stayed locked up with the clutch pulled then it suggests that the problem is either the clutch or gearbox. However also check the rear brake (for example, with drum brakes it they get very worn then the operating cam can go over centre and lock the brake on, or if the material comes off one of the shoes it will jam the brake) and also the rear wheel bearings.

However as you say that it then had problems starting then it suggests that it is an engine problem. If it had nipped up from lack of 2 stroke oil then it would probably not have run for more than a couple of seconds after you restarted it. However it is likely to have trashed the piston.

Oh, if you cannot see the oil bottle then check the oil pipe down to the oil pump. Fairly certain it is a clear plastic tube, so you should be able to see if it is empty or not.

Personal feeling is that it has probably just worn out and niped up. If it is a UK model MTX then it should have a steel bore and can be rebored (don't know about the later model imports which seem to have quite a different engine). It is quite an easy engine to strip the top end off (I used to have an MBX125, basically the same engine), so I would suggest whipping the top end off and having a look. You will need new gaskets though.

All the best

Keith
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