Welcome back.
Not had time recently as im also rebuilding my wagon’s tdi block and working on my boys ww2 jeep. Just love spannering.
Just been out to look at her, and once warmed, in neutral, i took her slowly through the revs. And she stumbled at almost exactly 4000 revs upwards. I’ll check the pick up resistance anyway, but i think im with scottie on the carb. The last run i did, i was cruising and opened the choke slightly, and she bogged right down, so my next try was going to be a smaller jet on the left carb, as thats probably the main area for high rev cruising. The right carb is opened up( drilled jet, raised needle and drilled slide holes), but that usually only kicks in for throttle, (was going to bore scope it when running to try to see how far it opened at cruise) although its easier to put back to standard without stripping the bike. I have spare stock slide and 125 jet. Whats your best guess?

Check air filter box for oil due to blow-by. Maybe for a test re-route the crankcase breather into a small Coke bottle.
Check intake rubbers for leaks (vacuum is taken from there to open second carb).

Andy

Intake Rubbers were old and finished when i sprayed them so have new ones from tourmax. Put right carb back to standard. Running her in neutral with remote tank etc, no airbox, she still stumbles at 4k slowly going through the revs. Measured the pick ip resistance and was about 117 ohms so in range. Going to get the timing gun on her to see if it advances to the second position at 4k. Hopefully borrow another cdi to test. Then ill look closer at the carb. Might be a blockage or as said above, an ai leak in the guel pump tube or enricher tube on right carb. Couldn’t really see much lift in R/H slide on throttle

How would you use the timing gun on that alternator without a lot of oil spray?

Andy

Dunno. Not tried checking the ten before. Might be fun. Or not. Still the possibility that second carb isnt performing so ill put a vacuum gauge on to see if its opening enough. Not too sure if the slide would go up that much if its not under load? Wish i could remember when it first got noticeable.
You still got money on air leak? I hope its that simple and not the cdi

So in answer to Andy’s question, you don’t , you and your place become an action scene featuring Red Adair and gulf oil wells.
Next is to plug my mates cdi in and try. After that ill know to start again on the carb.