Hawk 400 gas mileage

[old smokey]

This could be for anyone wanting to help send me off troubleshooting.
I've been using the 400 Hondamatic as my frequent rider to work (unless forecast is higher than 70% rain chance).
It was getting around 44-48 mpg per tank.
The last 2 tanks now it's getting around 36-37 mpg.
I pulled the plugs tonight and the left is darker than the right.
I think the pictures exaggerate that a bit.
Do you think this is a carb problem?
I haven't really noticed any change in the performance or idle of the bike....

[old smokey]

this is the way the left cylinder looks. It has a little oil seepage at the base of the left cylinder. This is maybe slightly more than the right, but not by much.

[old smokey]

this is the left cylinder photo taken early spring 2012. I guess the oil stain has grown downwards over the last 1500-2000 miles.

[reed]

Dave,
Its time for a good tune up oil and filter Valve clearances air filter plugs.
Timing chain adjustment plus i would look into the carbs etc.
Thanks.
Steve.
PS if you need any help i am a phone call away!!

[old smokey]

Hi Reed,
Maybe I'll just add this to the winter project list and then decide which winter it will be...
It almost falls in the category of selling it as is, keeping it around to try and fix up, or just keep riding it as is.
Reed, if we lived closer to one another I'd probably pay you to have it done.

[old smokey]

I rode the Hawk again today. Last week I was noticing how the chain was getting loose and there is "rusty" powder on the back rim. Today after getting home I looked a little closer and see the rear sprocket has a definite leaning to the teeth. I think it's done being ridden for this year.
It needs new sprockets and chain, front fork seals, front disk brake or pads, a major tune-up and some gaskets.