Motorcycle Repair: Warm Up, yamaha seca 400, air leaks

Question
I ride an 82 Yamaha Seca 400 and the bike runs great after it warms up. The issue is the left cylinder warms up after about 1 to 2 minutes but the right cylinder takes 5 to ten minutes to get warm. I am measuring this buy the exahust. I'm not sure if the most likely reason is compression, fuel, or poor spark. the plugs are new and are sparking and the carbs are freshly cleaned. Compression is a little lower in the right cylinder but within the operational limits set in the repair manual. Do you have any ideas? Thanks.

Answer
Hi Kris.

Start by checking the valves (intake and exhaust) as well as the valve timing for both cylinders.

 Then check compression.  This is not the most likely issue, but it is possible.  Use a compression tester to check it.

 Also check the carb synch and the intake manifolds.  One or both of them could be in various stages of leaking, which would create problems with mixture.
Check the plugs and see if they are showing signs of running lean.  This would indicate that they (one or both) have air leaks in the system.

Start with those and let me know what you find.
Good luck and ride safe.
FALCON