Scooterotica

i know im tempting fate , but i bought a AF DC electronic kit when they first came out ( late 80`s ?)then changed the stator to the AC version when they came out, still use it today.

reeds!!!

Had a very similar problem last week and it turned out to be the spark plug. Spark looked fine with the plug out the scooter, but obviously was failing insitu. If you haven’t already tried one (and I imagine you have), try another plug.

Cdi change; no difference connections look good.
Stator readings spot on.
Woodruff key mint.
Stator looks brand new.
Was very easy to turn flywheel by hand, would knackered reeds cause that? I'm hoping I haven't wrecked the top end but the plug was a lovely dark brown colour so I'm not expecting to find a holy piston.
Best get out there and take the reed block out I suppose.
I'll let you know what I find.

Ring peg.
Big gouge on the inlet where it's come out and a mess on the other side of the piston where it was pressed against the barrel after the ring spun round.
Less than 3.5 thousand miles on the kit too.
Bugger.
Bugger.
Bugger.

Exhaust port too wide?

Unaltered kit Adam so I hope not.

What oil and what % are you using?

I ask as people are always going for the upper limit of exhaust port width, which is 70% of bore. This is because modern rings can cope with the constant ring bow and flex at this width, however, whilst the rings may cope the ends then tap, tap, tap against the ring pegs and...

IMO the dyno prompted search for BHP figures and the ability of modern rings to cope is frequently showing itself in highlighting the next weak link in the assembly; the ring pegs. Reduce port width and you'll reduce the pressure at ring ends / peg, thereby reducing failure rates.

Standard port is under 70%
I've seen pegs let go on bridge port barrels which have each side less than 35%.
I've seen pegs come out in many different types of piston too. One of my customers had a peg come out on a barrel 2 years after it was built, he just had a new same size piston put back in and a new head as it damaged the squish face, that has run for 3 years to date with that same second piston.
My conclusion is that pegs can fall out and if you have one fall out your just unlucky.