After a bit of thought I came to the conclusion that a probable cause of the problem could be that I was not getting full opening of the throttle, especially going by the excessive free play in the twistgrip.
So I popped the carburettor off and had a look. Sure enough I was getting, at most, half throttle! No wonder she felt a bit flat!.
I tried taking up the free play with the adjuster on the top of the carburetter but this did not have enough adjustment so it was up to the other end to see what I could do there.
My LE is a composite of a MkII chassis with a MkIII engine unite. Can’t speak for the later models but mine is fitted with a involute scroll twistgrip and these tend to have more free play than the more usual “drum” type grips.
Looking at the twistgtrip I couldn’t see how it came apart so I posted a query on their Facebook page.
From the replies I found that there was a bar end fitting securing it in place, originally these bikes were fitted with an open end grip on their bars exposing this but my bike has been fitted with aftermarket closed end grips which had hidden this.
A blast of the heat gun persuaded the plastic gip to soften a bit, enough that I was able to remove the grip and once that was off it became obvious how to take the twistgrip apart.
Having had a look I saw that the inner cable was too long. I could try to move the cable nipple back along the cable a bit but I’ve never had success in trying to re-solder onto a used (and oily) cable.
The other option is to make up a cable stop to effectively lengthen the outer cable, looking round I found a suitable bit of brass bar so its off to the lathe!.
I soon had the cable stop made so next thing is to try it on the bike.
Well, it fitted in place without any difficulty but I now had the opposite problem, not enough free play! I had now spaced the cable too far out from the original stop.
As the cable had seated very deeply into the original stop all I had to do was convert the shouldered stop I had made into a simple spacer bush so the cable no longer bottomed out in the original stop.
Problem seems to have arisen because there are 4 different throttle cables listed for use on an LE Velocette so it’s 3 to 1 that I have the wrong cable fitted, problem is that with a hybrid bike like I have which cable is correct? Still, my little bodge gets the little lady up and running and is easily undone, next time I’ll probably just make up my own cable for her.
Now the reason I could not see how to dismantle the twistgrip was that a closed end type grip had been fitted, one in an inappropriate colour for a staid old lady like the LE so I went and bought a pair of black rubber open ended grips for her.
Now looking at her, although it is as standard, the throttle side grip has a shiny metal end cap with an acorn nut on it to close off the bar end while the clutch side is bare, black, open handlebar end so I’ll have to do something about that, a bit more time on the lathe is in prospect!.