Operating Temperatures

What is the usual problem when one cylinder operates at a different temperature than the other? I'm talking about a two cylinder Maxim 400. After a 50 mile ride, I left the bike idling and "shot" the laser thermometer at different hot areas of the engine (plug base, head pipes, lower block) with one side around 220 F and the other around 200. The plugs look good so I'm guessing it's a minor problem, but one I would like to sort out.

Thanks,

MaximAl

 

Two things come to mind, carb sync, and Pilot screw adjustment.
If your carbs are sync-ed and your plugs look identical, then. . .
20* isn't really a whole lot to worry about.

 

One cylinder running a bit lean, perhaps.

 

Is lean the cooler or hotter side? (I assume cooler due to less fuel) And to adjust, do I turn in or turn out the idle jet screw. I've got them both at exactly 3 turns out. And please don't tell me I have to do surgery and get into the carb to get to the other jets.

I also wonder if there is some sort of spec or range of temperatures that we should be seeing now that there are these awesome temperature readers. Like, "acceptable temperature range for this model at the spark plug base is xxx to xxx F".

Thanks again,

MaximAl

 

Lean would be hotter, turn the pilot mixture screw out to make richer.

 

Should I cool off the hot one (220F), or warm up the cooler one(200F)? Both plugs indicate good burning.

Al

 

Set your bike up for the best seat-of-pants feeling setting off from a light, and shifting gears, then match the color of the plugs- - after doing the carb sync- - which is after adjusting the valves.

You can tune one carb at a time.
Write down notes of every change, the exact position of the Pilot screw, and your opinion and observation.

You will be turning the Pilot screw less than 1/16 of a turn at the end of fine tuning. (|) - (/). Each test session, with notes.