Hi all, as per my intro post trying to get back into riding again but it has been a few decades since I had to fix them.

I recently was given an old 2 stroke 74 TY250 trials bike.

It had been sitting in someones shed for a while but done the basic checks, etc and it has been running ok for the last few weeks until now.

Now it won't kick over anymore and I can confirm the following...

You'll have to excuse my ignorance as It's been a while since ive done this.

Got spark (put new spark plug in) spark is good, every kick and looks strong.

Petcock is fine, fuel is going into carb, thought I would take the carb off and clean it but when I opened it up I was suprised how perfect it looked. No varnish, jets, floats, etc were 100% clean and looking good!

Fuel is getting to the spark plug. Confirmed this after taking the plug out after a few kicks and fuel was on the end of the plug. Looked a bit oily though? I am running 32:1 so I assume thats ok?

Assume air is getting in too as the filter is ok, nothing seems to be blocked.

Thumb over confirmed good compression, haven't got a tester on me though but seemed to be ok.

I read somewhere that the kill switch wire on the bar could be fouling, I will have to double check that when I get home but I have taken it off the other day and pretty sure I didn't see any loose connections, etc....I will confirm this soon.

Sorry about the long message, I'm just lost at the moment.....Got good spark, got fuel, got air, got compression?

I did get it going a few days ago by adjusting the idle right to the start and gave it 1 3/4 turn out and it fired up. Ran for a few days but then left it for about 3 days and now can't start it.

Thanks for any advice!

Hi andy, " well if you have a spark ,that rules out the faulty kill switch, and plug is wet, well thats strange , sounds like the fuel quality. change the petrol. if this fails i think compression low.

Iv seen a bike barely start, wouldnt rev just died, took barrel off, piston rings stuck in grooves of piston ,

Thanks for your reply...

Drained the old fuel, drained the carby and ran it all out.

Put new fuel in and ran it at 50:1 just to see if there was too much oil but no go.

For the hell of it I put the old spark plug back in (looks about 20 years old) and it fired up first kick!!! What the????

Now It's running perfect...lol

I have no idea, the other plug was brand new and is the exact same NGK spark plug with same codes, etc.

I did have it running with the new plug a few weeks back but all I can think of is this new plug may have been dodgy???

Spark plugs can be so temperamental on 2 strokes, good you got her running.