Motorcycle Repair: hard cold start, dual carbs, xr200r

Question
When the bike sits for 1 or 2 days it starts fine. If it sits for a week or more it takes 20 minutes and a lot of sweat to get it going. 1985 xr200r with dual carbs. Any ideas? Bike will fire and run for about 1 second and then not hit a lick for a lot of kicks. Choke is on and I never touch the throttle.
Thanks

Answer
Chuck, apparently that 2 carb setup wasn't working real well for folks, as I see they went back to the single carb in 1986.

I always suggest that people establish a baseline, before digging deeply into various systems.

Check compression and do valve adjustment. Check compression again, if the valves were tight.

Read the spark plug and see what it looks like on the end... brown, black, dry, oily, fuel fouled, etc. Put in a new plug and check for spark quality. Check the spark plug cap for excessive resistance... should be around 5k ohm and not a lot more.

Drain the carb float bowls into a small container so you can see what has been sitting in the bottom of the bowls.
With bowl drains open, turn on the petcock and watch for fuel flow through the system. If restricted, check the fuel screen on the petcock (requires draining tank, removing the petcock). Realistically, a 20 year old bike should have the carb overhauled, if no one has been into it before.

Try starting the bike with NO choke. Remove the air cut valve cover and check the diaphragm for holes, tears and replace if necessary. There is a spring and o-ring under the cover, so do it carefully!

http://www.powersportspro.com/partsfish/  will get you into some illustrations of parts for your bike.

When the bike starts/quits, check the spark plug... look for a good spark first, if there, see if the plug looks wet or dry. Wet=excess fuel from some source... float level too high, choke circuit leaking, wrong jets or idle mixture screw settings. Dry= not enough fuel or too much air.
No or weak spark.. check for pulser coil output issues, kill switch wire connections or switch contact corrosion or shorting out internally. Do check all electrical connectors on the bike for clean and tight connections.

No sense wearing yourself out to crank up a 200cc engine...
It is either not getting compression, spark or fuel.. or too much fuel.

Bill Silver