Hi I bought a TY80 some time back for my daughter who now has a renewed interest in having a go at some trials with me. It's a bit of a mess by all there. Anyhow I tried starting it a couple of times and no luck. Here is the current synopsis

- carb rebuilt with new jets and gaskets

- lifted the head, no problems there and fitted a new base gasket and annealed the head gasket. No movement on the crank

- compression test shows 100psi

- good spark, running an NGK B6 plug

- petrol getting through as plug is oily

- checked the reed valve and that seems to be seating alright.

I'm thinking that it may possibly be the crank seals? Any opinions or how I could check. In the past I have made a plug and pressurised the cases to see if the vaccume is held. However there may be an easier quicker way. Also if they are gone how hard a job is it to replace them. I assume I'll have to split the cases? Or can you just drift them in?

Having said all that, take a step back and see what is a beautiful Jewel of a bike. Perhaps I should have bought a TY instead of my OSSA

Is it sparking at the right time?

Edited May 2, 201610 yr by spen

Hi Spen CW here. Yes the thing was running a year or so back.

Has the timing slipped? Worth checking.

Just realised who you are, Colin.

I'm fairly certain you can prise the old seals out and gently 'press' the new ones in.

Slack off a couple of the crankcase bolts to give yourself a bit of movement.

Hi,I had a similar problem with a TY80 that had been unused for a couple of years. It turned out to be the ignition flywheel side crankshaft oil seal that had gone,it was easy to tell because fuel/oil mix had found its way into the flywheel casing area. it was just a simple case of removing the flywheel and back plate,hooking out the old seal (carefully!) then fitting a new seal. Hope this helps.

Hi,I had a similar problem with a TY80 that had been unused for a couple of years. It turned out to be the ignition flywheel side crankshaft oil seal that had gone,it was easy to tell because fuel/oil mix had found its way into the flywheel casing area. it was just a simple case of removing the flywheel and back plate,hooking out the old seal (carefully!) then fitting a new seal. Hope this helps.

It will help greatly, there y' go CW.......

Hi. Back at it again, still won’t start. So here’s what I’ve done

1) new crank with fresh seals. Got really good compression

2) new points, condenser, coil, plug cap, plug. Massive spark. Timing also set

3) new jets, carb cleaned thoroughly, float height set spot on.

It still won’t start. So question is have I missed anything or do I just set fire to the f****ing thing and move onto another project

I just add a little fuel through the plug hole to help things along. Are you sure your grounds are good? 

Yes I’ve done that, still no joy. So is it bonfire time then?

Is the crankcase full of premix?All the fuel that's gone into it has to be somewhere,it hasn't burnt it

After much kicking, swearing and throwing spanners about I managed to get it started. Not sure it'll go once again once its cooled down.

 

Anyone want a freshly restored TY80. Its taken me so long that my 13 year old daughter is now in the market for a Ford Fiesta!