Honda-SOHC

I’m having issues with the running of my CB550 and could do with some advice.

Carbs refurbished by Gerben - new main and pilot jets and fuel cut off valves (stock sizes 38 pilot 100 main)

Boyer Bransden ignition with micro coils - new 5k plug caps

Several sets of ngk d7ea plugs

Delkevic 4-1 exhaust.

Stock air box with new filter, inlet carb rubbers and o rings.

Ignition set, carbs synced. Bike starts and idles fine.

From idle to about 1/4 it runs really rich and stutters and bogs. Runs fine from 1/4 to wide open throttle.
I’ve used a colour tune which confirms it’s running really rich in the problem area.
It keeps sooting up plugs because of this.

So far I’ve set the air screws at 2 turns out, (1/2 turn leaner) which helps a bit.

I’ve checked the float levels with a gauge and clear tube method. They were almost level with the float bowl so have lowered them by a few mm which hasn’t made any difference.

I’ve have tried running with the needles 1 position lower which helps quite a bit with the low end running but then runs lean from half throttle onwards.
Have considered keeping the needles in this position and jetting up the mains to help the lean top end running.

I’m at a bit of a loss as I’d of thought it should run fine on stock settings even with the delkevic exhaust.

Any advice would be greatly appreciated. Thanks. Luke.

Hi all. Apologies if this has been covered before, I have searched but couldn't find the exact answer.
I've just had my V5 for my 1976 CB550 import.
If it was a uk bike what plate would it of had in the 70s? Would it of been a pressed aluminium plate, or the type with the separate digits stuck on?
From what I've read I assume a black and silver plate could be displayed, but I'd rather have the type it would of had originally if it was uk registered. Thanks. Luke

Hi guys. Looking for a bit of advice and experience regarding carb rebuild kits.
I'm only after the perishable items really so the o rings and float bowl gaskets.

I've seen the kits offered by keyster and cruzin image but have heard mixed reports regarding their quality and don't really need all the new brassware that they come with.
It's either them or a gasket only kit  from David silvers that comes to £74 which sounds excessive to me.

So my question is does anyone have any recommendations as to which kits to go for? Reasonably priced and preferably uk based.

The bike in question is a '76 cb550. Thanks luke