Anyone have luck with the 123 ignition?

[ted698]

Sanhozeezee - it sounds more like fuel/carbs then ign timing to be honest.

Kadrons are actually very simple carbs and easy to set up, but the commonest things to check are:
1 - Fuel pressure - they only like low pressure 2psi MAX (note a stock VW pump bangs out about 6psi) - so you need to control the pressure or it overwhelms the jets/needles and runs mega rich.
2 - Accel Jets - engine off - with the engine not running, press open the throttle smartly - you should see a nice steady clean jetstream of fuel squirt from the brass tube straight down the throat of the carb, and not hit the sides.
3 - Accel Jets - Engine running - if you hold a very fast RPM - eg 3,000rpm you should NOT see any fuel dripping or siphoning from these brass tubes, if it is again this screws the fuelling - carefully bend up the brass tubes higher away from the carb throat.
4 - Needle float valves - take the lid off the float chamber, check the needle valve works and shuts off the fuel, replacement needle valves use both copper washers under them to set the height. whilst your in there check the floats actually float, and are dry inside.
5 - Jetting - whilst in the fuel bowl - Standard Jets are 130 Main screwed in the bottom of the bowl - 130 actually means 1.3mm so check with a drill shank that it is what it says it is.
6 - Idle jet - screwed in the side of the carb is another small jet - stock are 55 idles - you don't normally have to change these - 55's work in 95% of cases, however people take them out and see the big holes drilled around the side - these are the air holes, the jet orifice is actually right on the end nub and its small - 55 (half a mm) check this is clear.
7 - Emulsion Jet is located into teh center top of the body under the float lid and is pressed in place and not designed to be changed - again in 99.9% of cases don't touch this - but they do break, so check the jet is complete by dropping a drill shank down the jet orifice, it should go in about an inch - check both to make sure they match.
8 - excessive wear in the throttle spindles - you can now buy new throttle bodies to replace these.
9 - make sure you have a Venturi fitted! they can be removed if your carbs are secondhand.

A very good guide is KaddieShacks own strip/down repair guide here:
http://kaddieshack.com/kadron_rebuilding_instructions.html

[sanhozeezee]

[VDM72]

@ted698 - having only had experience with things like 009 where you 'set' the timing to around 32 degrees BTDC at 3500rpm because "009's are all in at 3500"...do we need to do something similar with any dizzy we're using because non-stock 28-32 degree BTDC is what aircooled engines need?

The 'out of the box' curve with the 123 seems to be lower that, but still seems to work OK.