Sorry fellas but this has taken forever to sort out. Vacuum gauges out on loan to someone else.
(Dark Skies) i may not have made myself clear when gabbing on about fuel service level so here is my fuller explanation. Manual says something like 3mm below Lower face of carb body plus or minus 1 mm. Section 3-4 in the manual
Just got back with the gauges and bike red hot so a little unconfortable in the tickover department and as i filmed this four times it was at meltdown when i had finished.
This is the static fuel level for carb #4. It makes no difference if you have the bleed screw open or shut it reads the same after you blow backwards down the tube to push the air bubbles back into the float bowl.
This is the onboard tacho reading for tickover for the by now very hot engine i estimate this to be about 750 RPM or thereabouts.
This is the plug in analoguge tacho and it reads about 1500 RPM which i take to mean about 750 RPM if you divide by two
This is the vacuum reading that i set about 2 years ago. It has not drifted much in that time although the bike has been used very well since then. As you can see they are broadly in agreement but you would have to be very anal about getting it any closer. The state of tune of the bike, its general performance, its brakes and handling and the age of the instruments (carburettors) does not in my opinion warrant better or closer agreement. Each to their own. I rarely drive the bike with less than two thirds throttle so its not so important to me but if you are a potterer then it would be worth spending more time getting the balance correct. Of more interest to me is the vacuum of acceleration and and of full throttle and if you look below thats' exactly what you should see. Sorry about the over exposure but we had our summer here yesterday and the big orange thing made its annual appearance.
To show that they are the same in the fuel service level department simply move the tube to the next fuel drain and open the screw whilst running the engine. May not be obvious from the picture but this is number three and as you can see it is more or less the same as number four. Must point out here that because the float bowls are on an angle the tube needs to be in the same position on the float bowl of the reference carb in order to make a proper comparison. Obvious i know but i just wanted to be sure.
When you put it all together you get the following.
If you look closely you can just see the fuel level in the tube rise a quarter of an inch or so as the drain screw is opened. I had already done this several times by now so had emptied a little fuel from the tube to try to show the situation visually.
Click on the clip to open the video.
I did do a short video clip of pulling the choke out to show the effect of choke circuits on the vacuum gauges which i had intended to put in at the top since it needs to be done first. However the bike will not take choke at all when its in fission state and the video was a little difficult to make sense of. I can tell you that all chokes were operating perfectly and in closer agreement than are the throttle butterflies in the above clip.
What you cant see from the video is the individual bars osscillating and its one reason why i dont like Carbtune gauges. I had to sell the very posh gauges i bought for this bike and have regretted it since. You cant adjust the dampers on these gauges and you cant regulate the response either. When you look at these gauges they tell you nothing really but the other gauges had the capability to be manually tuned and this highlights a range of other potential issues with the carbs. Example; you can open the dampers and then tweak the air screws on tickover to get a stable air flow without fluctuation which i take to be a standing wave of pressure or a blocked jet which ever seems most appropriate, knowing your own carbs.
I hope this clears things up a bit. There is a size limit for vid clips on Photobucket so have had to limit the size for their benefit and for those on dial up on this site also.
AL
P.S. this did give me a guilty conscience so i went and balanced them perfectly afterwards!!!!
When I go down the scrappy I'll buy any 316/304 stainless or ally regardless of shape - it goes into stock, and it always comes in one day 
