running lean please read.

[kevinwcarr]

i have a 1983 gs 850. i know the valves need adjusted, they are tight but not to the point where the bike is hard starting. in fact the bike starts easy and runs perfect. we know its running a lean because we looked at the spark plugs. stock air box. original exhaust. the air box is pretty much air tight, i checked. carb boots and orings are fine also. my question is can a bike run lean if the valves are to tight? thanks in advance.

[Nessism]

Could be lean but if the bike runs well it most likely isn't THAT lean. Maybe try shiming the needles (do a search for info) and running some Seafoam/Techron gas system cleaner?

[Steve]

Tight valves will not cause lean running, if that's what you mean.

How do you know the valves are tight? If you had it apart and measured them, why didn't you adjust them while you had it open?

How did you run the engine just before reading the plugs? You really need to to proper plug chops to get accurate readings. If you idled the engine while coasting to a stop after a ride, you are only reading the pilot circuit, not the main or needle circuits. You can richen the pilot circuit a bit by turning the idle mixture adjustment screws on the tops of the carb outlets.

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[kevinwcarr]

my mechanic replaced the base gasket, head gasket, and valve cover gasket. he checked valves but he didnt have the proper shims . the spark plugs are not burning a ligh tan color, more like a white color but not too white.

[greg78gs750]

at what throttle setting are they lean? idle? 1/4? wot? it's my understanding that our bikes were set a bit lean stock.....might just be "normal"....