New to me 1980 GS450S

[jaymechie]

Just got this 80 gs450 last night. As of now it hasnt ran since June, but today I got it running while on choke. Id give it some gas and it would die. I should add that it is very inconsistent, doesnt start up every time. It also seems the fuel line does not have a "consistent flow". like fuel is very sporadic in being pumped, and theres an air bubble. I have a video of it, but not sure how to show it on this forum.

[rphillips]

Set petcock to pri., that should hold fuel delivery wide open. Welcome aboard & good luck.

[LAB3]

Start with your basics. I'd just assume the gas is old and drain the tank taking out the petcock and giving the screen a good cleaning. You'll notice some washers on the petcock mounting bolts, get some fiber washers the same size at your local hardware store to replace those. Swapping out the fuel lines with new ones is cheap and easy, head down to the auto parts store and get some bulk line for that. While your at it grab a new piece of vacuum line that goes from the left side carb to the petcock. Check the resistance of the spark plugs caps, they should be 5k ohms, clip off a small bit of the spark plugs leads before reinstalling to assure good contact.

[dorkburger]

Cool bike. It would probably be best to fully go thru the carbs / fuel delivery from start and eliminate questions.

[LAB3]

Cool bike. It would probably be best to fully go thru the carbs / fuel delivery from start and eliminate questions.

Normally I'd advise that too but if the bike ran last June it would be better to take the "if it ain't broke don't fix it" approach.

[limeex2]

If it will only run on choke it is broke. Ethanol gas takes about 8 weeks of sitting before it starts to affect idle and starting circuits. Fix it right and keep that crap out of there!