I treated myself to a pair of those lovely independent choke plungers - one for each carb. After a bit of fettling they fit perfectly, but still the rh cylinder is running rich 
Have you tried swapping the carbs over temporarily to see if the richness swaps over to the left side?
Are the needles both on the same groove?
The needles ARE on the same groove. It never occurred to me to try swapping the carbs - that’s an excellent idea! Am probably going to be away for a week and a half now.
Carb rebuild kits arrived today. So, when I return, I will update you all with my progress.
Cheers,
Steve
1 Like
And now you know the joys of a parcel from Eurocarb. Pass it on (o;
Was like Christmas and birthday rolled into one 
1 Like
I believe the correct Float height is shown in that earlier diagram, I’m curious to know which manual tells you to set at 18.5mm. The original factory manual showed this diagram for all models and 850 Le Mans owners were tearing their hair out trying to conform only to discover that the correct setting for their 36mm PHF carbs is 18.5mm.
Hi Jay, this is the source of my float height information. The paragraph follows 2 sections referring the VHB and PHF carbs, respectively. I am puzzled because my carbs have 10g floats but the heights are set at around 24.5mm (the setting advised for 14g floats).
I don’t think incorrect float heights are my problem, as one cylinder appears to fire correctly whilst the other is rich, but the float heights are the same on both carbs.
Cheers,
Steve
Ah, I forgot about the Haynes manual. Yes it’s a source of information but not always helpful. Float height is very important. The factory manual gives the float height as per the above diagram so I would go with that.
And because I just can’t let things go, I’ve just dug out the original carbs off my T3 which I know were never tinkered with because I bought the bike brand new. The 10g floats measure exactly 24mm.
Hi Jay,
That’s reassuring - I thought I had the wrong floats and/or the wrong heights, but I’m happy that they are okay.
Of course, I may have a leaky float ;causing the rich running) but I’ll check that when I fit the rebuild kit.
Thanks for your input.
Cheers,
Steve
Garage day today. Stripped the carb’s, cleaned and reassembled with new seals, gaskets, etc. Reduced the main jet size from 135 to 130 (it has K&N’s fitted). Set the mixture at 1.5 turns out and the throttle stop at 2.5 turns out. Installed lovely independent choke mech’s again.
Bike starts and runs better (feels quite nice to me), but I still have a left-hand plug normal and a right-hand ‘sooty’ plug.
Any suggestions please before I book it in with a mechanic?
Cheers,
Steve
Swap the carbs over and see if the issue moves with the carbs.
Thanks - I forgot about that one.
Is it definitely sooty, not oily?
Definitely sooty - dry black powder.
UPDATE: switched the carbs over and took the bike for a 25 mile run last night. Whilst it runs a little rough, I removed the plugs and …… no problems 
! I cannot pretend to understand why.
I have today returned the carbs to their rightful places and will hopefully get to make more progress tomorrow. The plan is to take it for a decent run then try out my NEW😃 vacuum gauges! I WILL get this bike running properly.
After that, there is a Gunson Colortune winging it’s way to me through the post as I type.
1 Like
Hi been following this, I had same problem… Tried new needles, was shocked at the amount of wear when I used a magnifying glass… Done float levels, new enrichment plungers… Basically the same as you and could not sort, then Temu offered me a PWK carb for £6 so brought that and another one for £24 two rubber adaptors £6 and a pair of alloy bellmouths for £8. Put them on and virtually straight away cured the problem. Played about with jets and the bike is running better than it ever did. I know this doesn’t help you, but to be honest I got fed up not being able to cure it etc.
It IS proving to be a bit tricky. Took it for a spin last night after switching the carbs back - sooty plug again. Baffled!
Tried the vacuum gauge this morning. That resulted in a few adjustments. The idle and mixture screws are at quite different settings for each carb but I’m going to stick with them until I can.get out for a decent run again.
The Colortune is on it’s way …. 
Where abouts are you, maybe someone local to give a second opinion in person.
I’m in North Staffs. The people in the local branch are great. I may just do that
1 Like
There are quite a good few in the Staffs area, Kate Bezus’s partner, Guy Wain is very good at fixing old Guzzi’s