Honda-SOHC

Ooops! Didn't notice you'd put the carb number in the title

Hi Spannerbrat, I may have a spare arm for you if the carbs are the same as a CB650. Can you measure the centres of the bolt holes and let me know. On the main carb body just above the float bowl on the right side, there should be a number stamped. Regards, Clunker.

Today I freed off the clutch plates, lubricated the extremely stiff clutch cable, changed the oil and filter. While the clutch cover was off I got the polishing tackle out, 400 + 800 + 1200 grit wet & dry, fine wire wool, toothbrushes, tube of Solvol and bucket of warm soapy water. The clutch cover now matches the rest of the casings, just need to do the black circle with Humbrol Satin black. Rain stopped play!   Clutch works great though!

Use Deox-C from Bilt Hamber.

Does not affect paint or any other material. Dissolves rust but leaves good steel unaffected. Non-toxic and biodegradable.

It will clean the interior of the tank down to clean steel.

http://www.bilthamber.com/deox-c

I followed the link and this does sound like a good product according to the reviews but I was wondering if you have to treat the inside of the tank afterwards to stop flash rusting?

What you really need is a bucket! to go with your tube of Autosol

It was after I first balanced the kwak carbs, then tried adjusting the mixture screws according to the Books and plug condition, with less than satisfactory results that I invested in the Colortune. With the Colortune I could actually see how different the settings for each cylinder were, even though they were adjusted as much as possible to proper specs. I set out at plug 1 with the tank off and a motorcycle cover over myself and the bike, engine running of course, screwed in the mixture screw all the way then backed it out until the "bunsen blue flame" appeared then carried on going until I lost it, then backed it in again until "bunsen blue" again. Did this for each plug, also opened the throttle about a quarter on each cylinder to observe colour change in the chamber, got each mixture screw set so that the response was as close as I could get with each cylinder. I figured that if each mixture screw was set as closely as possible to the rest then that wasn't going to be a bad thing and balancing the carbs again afterwards was going to be as close as I could possibly get by myself without expensive equipment. Anyway, it sure did improve throttle response and performance. I'll just have to try it with the CB carbs, it's not gonna cost me anything to give it a go as I've already got the gear. Watch this space!

I will let you know how it works out with these carbs. When I used it on the kwaks I balanced the carbs first then used the Colortune then balanced the carbs again. Both bikes ticked over superbly and went like excrement off a digging implement. Both bikes were carb strip jobs that had been stood for years.

Well I got back on the bucket and pulled the carbs off again, I had managed to dislodge the diaphragm on the accelerator pump. When I removed the float bowl on no.2 carb I noticed a snot like substance in the bowl so I gave it a wipe out. Then I removed the other bowls and found the same crap in them as well.
The PO told me when I bought the bike that he had put clean fuel in the tank, he didn't mention that he hadn't drained the old fuel out first though. I emptied the tank into a bucket...............I have never seen fuel look as bad as that before! In the bottom of the bucket was a load of what looked like black silt with green snot mixed in, with a layer of really dirty petrol floating on top.
I had some clean but old petrol in the shed so I poured a couple of pints in the tank and gave it a right good swilling around then emptied it out, still dirty so I did it again and I think I got most of it out.
I put fresh fuel in and put the tank back on the bike, tried to start her up but the choke lever won't move, not even a bit Took the tank back off and operated the choke pulley by finger tip underneath the carbs, it moved very freely, thought I'd pinched the cable somewhere but couldn't see anything obvious. With the carbs in place on the bike you can't actually see the choke pulley where the cable locates so I traced along the cable with my fingertip, it wasn't connected to the pulley but was trapped inside the airbox rubber.
When I refitted the carbs it must have slipped out of the pulley and hung loose until it got in the way of me connecting up the airbox rubbers
I freed the cable and put it back on the pulley then tried to start her up again, choke worked fine, bike started but something didn't sound right, 1+4 headers were cold and 2+3 were hot.
This is the part where I love having two of the same bikes (or very similar) at the same time.
I borrowed the left coil from my Nighthawk and put it on the Custom, still the same, no spark on 1+4 so I moved on to the spark igniters, swapped both of them just to save splitting them, sparks on all 4 plugs  .
I put the plugs in, tank on, fired her up, all headers getting warm, let her run till she no longer needed choke. Switched her off then started her again, did this a couple more times just to check for any problems.
I forgot to mention that when I rebuilt the carbs I replaced the slide and needle in number 4 carb as the original slide had some deep scratching and the needle was distorted, probably due to the resin bodge on the carb body. The replacement slide and needle came from some CB650Z carbs but were exactly the same as far as I could tell.
Due to the PO's rather fanciful stories about he "did this" and "checked that" my next steps are going to be to free off the clutch while changing the oil and filter which he said he had done, check the valves like he said he had done....then balance the carbs and adjust the mixtures with my glass spark plug. So that is how she stands at the moment. I didn't take any pics of the above stuff as I just pulled up a bucket and started fiddling and one thing just led to another.