KZ305 / Keihin CV32 Carbs, float levels & Jetting

I have a smokey exhaust so I'm going all the way back up the system to sort out the carbs first.
My carbs leak, I have some holes in one diaphragm and my jetting seems all wrong.
So float levels, clear tube test. I have done this not so long ago, they looked fine but after a day or two the leaking continued. Not a lot but enough to my my garage stink of gas. So I've done it again today. After 4 or 5 times removing the float bowls & adjusting the tang I got both to 3.5mm. I wanted them at the lower level because the seals on the bowls look to old and compressed to be doing any sealing so I decided lower is best, 1.5 to 3.5 is the service level. The right one is giving me a few problems & does to appear to be making a good seal after some time the fuel forces it's way through then flows out the over flow. Maybe my bad petcock it not helping here - rebuild kit on it's way. I've inspected the float valves several times & although the look fine, the rubber is very hard and maybe not sealing as it should. That's my hypothesis, I have new ones coming so I'm hoping they will sort that out.

I've dome a temporary repair on my vacum slide diaphragm with Gorilla Glue it hold pretty well but I wouldn't trust it long term. The slide is moving down slowly but not a slow as the one I replaced last year so a new one is on it's way.

I had the carbs in the kitchen last night so I took a really close look at the jetting. When I got the work done on my bike last year I wasn't confident to go into the carbs. My local Mech. said he would take care of the jetting. I've seen a few jetting guides that advise on starting points for jetting. I have K&N pod filters but the stock exhausts. The guides will suggest 1 to 2 sizes up on the main jet. My carbs have a primary and a secondary main jet. This is never mentioned in the guides so I'll assume when they refer to main jet they mean primary main jet. So, my stock set up is #62 Primary & #85 Secondary. My mechanic left the primary & changed only the secondaries, one carb has a #95 the other a #96 - the jets don't even look the same! So I'm thinking he's got this totally wrong!

So once I get the float levels sorted & not leaking I'll be looking into the jetting...






After I left the bike for half an hour after setting the float levels as above...

It seems that 33 year old rubber seals aren't handling the daily riding like the used to. All my parts arrived during the week. First I did the petcock, now it functions perfectly. Next I replaced the float valves. Straight away the fuel levels changed so I knew the old ones were the problem. Interestingly the problem might not have been the rubber viton but the springy nipple at the other end. The new K&L replacements had slightly longer springy nipples, the effect was the the floats sprang back much more strongly when pushes in, maybe the old ones were worn. So after 4 or 5 attempts I got the fuel level to about - 3mm and reinstalled the carbs. Then went for the old 11pm road test. The bike ran sweet! (it has been rough as all week and leaking so much faster I had to put a G-clamp on the fuel line). So thanks to everyone who sent me down this path.
Next I need to get hold of some fine circlip pliers so I can get the needle into my new vacuum piston. Then I'll do an oil change. 2 questions on that.
1, could a thicker oil help my smoking problem? 10w-40 is standard I'm thinking 10w-30?
2, if my oil has been contaminated with fuel, will the filter be ok to re use if I drain it thoroughly first? It's pretty new.
Thanks
Hama

Also, any comments on my jetting issues as mentioned above?

10w30 is thinner when hot than a 10w40.

Ooops, my bad. How about 15w50? Good or bad idea?