Carburation issue?

[norbert]

Well, I googled Mrs. Schilling: a quite impressive personality

[MickeyMoto]

She was a motorcycle racer!

The BMW and Mercedes aero engines used fuel injection, the Rolls Royce used carburettors. It is always the simple ideas that help. I am glad modern bikes do not use carburettors!

[Steve Brown]

I know that it sounds strange. It' just a cheap way trying change the posicion of the holes of the atomizer. Nothing to Do with magic

This is a perfectly good idea in principle. Another way of achieving the same effect is to place a small shim under the throttle needle clip, so long as the shim thickness is less than the distance between the clip grooves on the needle you can get another small adjustment in needle/atomiser relation.
Placing the shim under the atomiser will also slightly adjust the relation of the atomiser metering holes and the float chamber fuel level.

My own bikes (Camel and 350 Sport) both responded well to altering the slide cutaway. Mine needed a larger cutaway to cure richness that I couldn't quite fix with the needle/atomiser.
The biggest improvement I ever had to carburation though, was by getting stronger sparks from the ignition system!

[FenlandExile]

It's been a while since I started this post, but wanted to just let you know where I have ended up.
I found some jets in the spares that came with the bike way back when. First I tried some smaller 45 pilot jets, but these caused the engine to stumble quite badly on pick up from idle, so the 50s were put back in.
Amongst the spares I found 112 and 110 main jets. I went straight in with the 110 ones, and having now done a couple of hundred miles like this I'm very happy with the way the bike performs. While there is still a very slight hesitation between 4.5 and 5K revs it's not enough to give any concern regarding rideability, unlike the serious issue I had before with the 115 jets. Has it affected top end performance? well not so as I would notice, and I'm not shy of using all the revs available as and when.
So I could try the 112 jets just to complete my testing as they had been recommended by some earlier, but as I'm satisfied with the way it is now I don't see the point.
So in conclusion it now has the needles in the lowest positions, 110 main jets and 50 pilot jets.
The only frustrating thing now is I'm very shortly moving house, then heading off to Canada for a family wedding, and immediately upon my return having a hip replacement. So it doesn't look like I'll be riding the old girl again now until next spring............

[FenlandExile]

Oh, and forgot to mention I put new 260K atomisers in too! Found them in that box of spares I mentioned earlier and as someone had said in this thread before these items can wear out thought I'd give the new ones a try.
So again, in conclusion, needles at bottom position, 50 pilot jets, 110 main jets and 260K atomisers.

[Morini Jen]

Thanks for the update, FenlandExile.

It is always useful information to find out what works best for each bike.

Wishing you all the best for the house move, the wedding in Canada, and the hip job...

Hoping that you will be back in the saddle sooner rather than later.