Running on 2 cylinders at cold idle

[rij1]

When I start the bike cold it only runs off #1 and 2 cylinders. When I have it running and I spray water on the exhaust manifold pipes only #1 and 2 sizzle but I can touch # 3 and 4 and it will be warm.
After the engine warms up it runs fine at idle. What can be causing this?

[TOOLS1]

Since it is #3, and #4 you can pretty much rule out ignition. I would look at the pilot jets. They might be dirty, and not letting the engine pull enough fuel to fire the engine cold.
TOOLS

[Re-run]

I second what tools said, however, as a precaution, check the plug boots on 3 and 4, make sure they are securely screwed into the plug wire. it's a quick check that costs nothing but a minute or so of time.

Otherwise, IF you want, there is simething you can check before you pull the carbs off.

Pull the drain tubes for #3 and 4 carbs and stick them into a cup or something that can handle gas. Open the drain screw just to make sure there is fuel getting to the carbs.

I have seen a fuel rail get clogged enough that fuel could not flow properly. Pretty rare occurrence but something you can check if you choose to do so.