New owner 81 gs550l

[81gs550l]

Hi all,
just purchased a 1981 gs550l with 10k miles seems to be very well kept for the past 35 years. I have noticed with just a few weeks of riding it's getting pretty bad gas mileage. After first riding it home and a few tanks of premium run through it she's running a lot smother. I'm new to working on bikes but have some mechanical know how any easy way to diagnose the problem? I though of adding fuel treatment at my next fill up any thoughts?

thanks,
jj

" I like mine with lettuce and tomatoes an ice cold beer and French fried potatoes "

[Darren]

clean and lightly reoil air filter and a new set of plugs and add
some seafoam to the fuel tank

[81gs550l]

where can I get seafoam other than Kmart?

[Guest]

where can I get seafoam other than Kmart?

Advanced Auto has it if you have those stores around.
You should post a picture of your bike for us to see. The avatar is too small.

[81gs550l]

Thanks. I uploaded a better pic of my bike.

[81gs550l]

It's getting cold outside