Runs fine with mix screw bottomed out (BS34)

[Forest]

I actually managed to get decent timing by soldering a thin piece of brass to the worn part of the bob-weight and filing the knob down to a 4 mm diameter Just how temporary this solution is, I don't know, so I also ordered spares from overseas (Mike's). I did the dead cylinder thing on both sides. With the mix screw all the way in, I set idle to about 1000rpm. Backing the mix screw out a quarter of a turn, the left side dropped very low and the right side died. So the behaviour is the same on both sides. Unless the idle backstop is set all wrong (and it doesn't look like it), I may have to take Jim's advice and get some smaller pilot jets.

Right now I'm waiting for parts and tools, so it'll probably be a while before I can get any further with this.

 

[MrBultaco]

I may have to take Jim's advice

Always a good idea...

 

[Forest]

I'm still waiting for those deliveries.

The season is coming to and end here and my insurance only lasts another month. After "fixing" the ATU and taking some slack out of the drive chain, it actually runs pretty good, so I've decided to just ride it for now, and get to know it a little better in the process. Then I'll get back to investigating at a later time.

Thank you every one for your support and suggestions. I'll report back if I find anything out.