MOPED ARMY

Sounds to me like you're not fully variating. I had that problem when I first got rid of my dimoby. Watch your variator while you're riding. Will it pull back all the way? You probably have to go with lighter weights. It's possible it's just stuck from lack of lubrication, too.

Or it could be something else. But the above was my experience.

re-read the post. states that the engine variates on the stand, but barely when riding

Leads me to assume exactly what I said. When the engine is loaded, it wont variate because of the wrong weight setup or poorly lubrication.

the reason I say this is because, as i said, I had exactly the same problem when I did the 50L to 50V conversion. Experience speaks for itself. Of course, it doesnt mean that's the problem here.

Give her a leakdown test to see if the spi seals are leaking. check that the collar on the Del is not leaking like they all tend to do. Make sure the timing is set to 1,5mm BTDC and tighten up on the spark plug gap.

Open up the exhause pipe a little if you ported the engine and running a 15mm carb the extra breathing has to go somewhere.

How is your belt?

Small air leak probably wouldn't cause this problem, but it may. When you're on mabecane's site look at the maintenance section, and read up on lubing the variator. That'll keep it all sliding easily. If your mounts are totally shot, it may cause it to not variate all the way, especially if the tranny side mount is in worse shape than the stator side.

I wouldn't worry about the spring. They're the same for both versions. Do you have a 3 ball or 4 ball variator? If you have a 4 ball, take two balls out. If you have the 3 ball, buy a 4 ball backing plate and run 2 balls. I have a 4 ball plate if you need.