Not all cylinders on startup

Just wondering if anyone else has experienced their bike not running on all cylinder at startup them them cutting in shortly after the initial fire up maybe 10-15 seconds. Another thing would be an idle below what you set which rises to a correct idle when warm.

Just looking for potential causes and fixes.

Float level off?
Steve

Fouled plugs

Low battery.

Good Fortune!

I had this exact same problem with intermittent firing on #1 & #2 --- it was poor spark plug wire connections.
Redo the connections --- you may need to nip off the ends of the wires a tad if there's the white crusty oxidation.
or get new 7mm copper core.

Old ignition coils --- the grey Dyna 2.2 ohm are supposed to be a good match for the stock electronic ignition, but you can use the green 3.0 ohm which are also used with the Dyna S ignition. I installed the green (fairly common).

Idle. on my 81 650-CSR i have to use the choke to start the bike (this is normal), adjusting the choke so that it idles at around 1500 rpms. after the bike is warm & the choke is off, i have the idle set at around 1200 rpms, maybe a tad less. the manual recommends 950-1050, but the bike seems to stumble when it's set that low. It could be that the tachometer is off, since it's old. I did a fairly thorough tuneup, so everything has been checked & set as per the factory manual.

I am using stock Kawasaki TCI ignition and Dyna Grey 2.2 hms coils for over 3 years now. No problems.
I use to have one cylinder not firing at start up using full choke... turns aout to be one air jet was blocked. When I opened a little the choke buterflys it would start firing normaly.

It could be a multitude of different things. Carb or ignition related most likely, but could even be improperly adjusted valves. What is the status of the bikes maintenance? Are the carbs and tank clean? Ever replaced the old crusty carb O-rings and vacuum synced the carbs? Carb boot condition? Does your bike have points and if so, how long since you cleaned and adjusted them? How about the ignition coils? Ever checked the voltage to the coils and have you ever replaced the wires and/or the plug caps? Status of the spark plugs? How long since you last checked/adjusted the valve clearances?

It's extremely difficult to diagnose running problems on a bike that has an unknown maintenance history. It's always best to update all the various maintenance aspects and then if you still have running issues you will at least know what the problem is not.

I just had the same problem when I adjusted my float levels. Turned out to be a bad HT connection. One thing at a time then move on.
Steve

If not already done, would examine spark quality on removed plugs while spinning over the engine. Should be fat blue sparks. Not wimpy thin orange sparks. And not absence of sparks. For this test, it's best to use brand new spark plugs of the type described in the Factory Service Manual

The spark plug wires may be old, cracked and worn out, and leaking high tension voltage.

A test for high tension leakage through the spark plug wires is to remove the fuel tank and provide an alternate fuel source to run the engine in a darkened garage (or anywhere it's dark). With the engine running, spray water mist on the spark plug wires. Not supposed to produce a free fireworks show, but fireworks indicate high tension leakage and need for installation of brand new plug wires.

Good Fortune!

The status of maintenace on the bike.

Valves checked and adjusted 2 weeks ago.
Coil leads have all been replaced with new HT lead. Caps were left alone.
4 New spark plugs factory spec.
The engine side manifold's age is unknown to me but seems ok.
The air-box boots have all been replaced, so has the air-filter.
I have recently been into the carbs and set the float levels, 3.5mm below the bowl split.
Tank hasn't been cleaned, I have seem some fine rust particles in the carb bowl even tho I have a inline fuel filter.
Petcock has all new OEM Components
All Carb Needle and seat's, & gaskets have been replaced with OEM.

To start the bike of a morning if I try without the choke and just some throttle it will start get to about 1k them die, then if i try again nothing.
Switch to choke it needs to be fully applied, bike jumps up to 4k+ have to very quickly turn it mostly off and get it down to about 1k then as the cylinders cut back in keep adjusting it as the rpm increase eventually turning the choke completely off. The bike then idles lazily at 800-900 before it warms up to an idle of 1000-1100

Once warmed up the bike runs good, except it could use some tuning in the mid to high rpm range cause of a 4-1 aftermarket exhaust, for now I have raised the needle by one slot.

It was doing this when I first go the bike I thought it was the petcock and needle valves leaking out all the fuel through the overflow.

Caps can go bad. You need a filter. You might have to clean the carbs again. The pilots are very small. Rust can clog them.
Steve

What you describe sounds sort of normal. The idle will be low until the engine warms up. Also, it's not unusual for the engine speed to increase with the choke on.

You might want to (carefully) judge how fast the header pipes warm up after a cold start. Vacuum sync the carbs too if you haven't already.