No problems Steve. I'm happy to talk 500's any time or place. Its not as though we are interupting anybody else.
My 500 Seiv has the 6 speed box too. I have a 40 tooth rear.
I certainly wouldn't want to try and pull up a steep hill, fully loaded with a pillion but it is OK for what it is. I don't know what the rear wheel rolling radius of an Excalibur is but if it is less than the 500 with a 110/90/18 on the rear then you should be OK. The 501 should be better than my 500.
Can't complain really. The little thing is a joy. I'm very lucky that I have a Lav Alpino and a Guzzi Monza as direct comparisons.
All the jets and settings are linked. There are places at throttle openings that each is more influential due to proportional fuel flow but there are no stop valves in there to cut off any circuit.
At WOT try the choke just a tad. If the bike improves then the main is small. Then turn the fuel taps off for a short time. As the fuel lowers in the bowl if the bike improves then it may be too big. You could try your 118 or simply raise and lower the needle. The 264T is bigger, much bigger than my 262T. The amount of fuel it can allow past an X1/X22 needle is something like 15% more at bottom of slide travel.
Doing the above test at WOT isn't really all that useful though. If you don't ride there then don't jet there, is my motto. If you find that the bike seems happier with the 118 but tends to foul at lower openings then I'd be looking at either a 45 or 50 slide or try dropping your idle jet. Dropping the needle a notch is an option too. One indicator that the bike is within a workable range at lower openings is if at best idle the mixture screw is around that 1 1/2 turns out. All the seals, etc need to be in good order, etc. When warm, from idle, slowly twist the throttle and see if the revs increase smoothly. If it hesitates then my guess is that it is too rich. You often read that owners increase the idle jet to remove this dead spot but in my experience it is usually too rich. Either way it can be adjusted out. Hold the throttle at the dead spot and with one of your other hands screw the mixture screws in and out to see if it improves. Othert than that hold the throttle in the dead spot for a while, kill the engine and have a look at the plugs. I have one of those colortune kits for this and as I've written, it is usually too rich.
When I buy an older pre owned machine that has been "adjusted" I invariably find that the happy spot is much closer to the OEM settings than the PO settings. The end of the carby era is slightly different as they leaned out the mixtures to meet increasingly tougher emission standards but still the happy spot isn't normally too far away.
Another trick is to clean and polish the end of the exhaust. Clean after every trip and see if there is any carbon. Plug chops as you have already mentioned a re useful too. Harder to do without burning your fingers on a Morini though.
![Laughing :lol:](./images/smilies/icon_lol.gif)
The guzzi is just a joy for this sort of thing.
Just some opf the stuff I do.
Hope it helps.
Rod