Hi Steven,

there's not too many (read that as I know of only maybe one guy), who uses a single carb manifold and overall the tendency on this forum is more towards going for two smootbore carbs in order to gain some extra performance.

That said, can you swap the coils between front and back to see, whether the problem goes the same way (it would be the first thing, I would try to have a look at, as it is the only thing left that is individual to one cylinder.
What do your plugs look like, if they are very dark it could simply be, that you're killing them with a too rich mixture ?
Which manifold are you using ? I saw some pictures of manifolds, which were quite appaling realy, when it came to craftsmanship. If so, there's shouldn't be any gaps, weld beads or the like on the inside of the manifold.
Lastly did you overhaul your carb before install and no matter what, unscrew the choke plunger and clean out the seat ?
Do you run a fuel filter and which kind of petcock - if your engine stops of fuel starvation, it wouldn't surprise me.

As you see quite a lot to try out and find out. My best bet is on the electrical side, because that is becoming more and more of an issue nowadays.

Cheers,
Greg

ok I swopped the coils and found that a wire was actually touching the body. fixed and ran it again.
I forgot to mention that I have to bump-start it every time for now.
When it takes it runs perfect for a while and its as if when I let off throttle it starts to backfire and eventually dies.
what should I check for first.
I haven't overhauled my carb so I guess it could be too lean at this stage.

Quote from nanno on 16.12.13 at 10:12:27:

How do you mount them????

Quote from Manfred on 23.12.13 at 13:52:08:

Please expand on the amount of type I am permitted ???

Sorry.... How do you mount different carbs... Do you have them independant  and  use a cable  1 int 2 ????

Quote from KINGPRAWN on 23.12.13 at 23:17:50:

You can of course write as much as you want. I just said to do reasonable quoting. As you can see in the previous post #8, one does not know what you mean if you just quote a full post.

Happy Christmas
Manfred

Why don't you get a Keihin of a KLR ? That's a single Keihin CVK 40 and would be a better choice. (Technically pretty much the same as the one fitted to a Sportster (and then you could roughly follow an 883's jetting), which should work quite reasonable.

I'd go (tongue in cheek) for a 135 mains and somewhere around the 40 mark with the pilots. But just slap them on and see what happens, it's not gonna end up in a straight nuclear meltdown, if the jetting is off. I'd wager a guess and say, the bike will start but start to hesitate at about half throttle.

Cheers,
Greg - by no means a carb-guru, just a tinkerer… (only to make sure, you don't get the wrong impression)

I tried in last summer with a 40mm CV carburetor.
and was not satisfied, had a 46pilot, and 160 main jet, tried in other sizes.
Problem was always the Backfire, and from 40km to 60km was not doing well.
If it was then, it was like rocket, but very high consumption of petrol


Now I'll try it with a 36mmCVK, times examine what happens
with a 165 main jet

Hi all.
Hope you all well. I want toi know what your opinions are on the "Gunson colortune" tool... it looks to be of great help to setting carbs.

Will this help me into the right direction?