Outer cylinders running lean?

[Rob104254]

Hello everyone I'm riding my grandfathers 1978 GS550E and I think it may be running lean on the outer cylinders, It seems they warm up much quicker than the inner two, is this normal? The bike has 10,000 miles on it I'm thinking its time to check/adjust the valves, but thought i'd ask the experts here first.
Thanks in advance,
Rob

[MisterCinders]

You might also check the coils and timing. If 2/3 are firing too early/late or intermittently, that could prevent the pipes from heating as quickly.

Whenever there is a doubt, always check and adjust valve clearances. They are the wellspring of happy engines.

[Rob104254]

I have a temperature gun and i'll ride it tomorrow to see what they all get to, It seems 1 and 4 are getting too hot, whereas 2 and 3 seem more normal, but it is cold blooded so 2/3 spark being off could be the case. I'm not even sure anything is wrong with it because the bike acts like it runs perfectly, I just don't want to do any damage to an almost new 33 year old bike. Thanks for the input MisterCinders

[Big T]

If you don't know the maintenance history, do all of it now

Slow to warm up:

1. Tight valves
2. Dirty carbs

[verde]

Since you're talking about warm up time, look into what's already been mentioned first, but I figure this is worth mentioning too. Does it still have the airbox? I ran into a weird inner/outer cylinder dynamic while running pods that is caused by the airflow around the engine. This pic was after a valve job and carb dip, but before syncing the carbs. Carb sync fixed this for the most part, but still slightly different inner/outer cylinder afr's at speed(not noticeable in the ridability).