QuestionI know you said mainly 70s and 80s but i bought a 92 suzuki gsxr 600 about a month ago it did not run at all and for no experience i think I have come along way but now I am completly stumped the bike will not start with electric start must be push started. if you use electric it just back fires. if push started it runs great has lots of power but after about 6 or 7 miles or ten minutes of riding the it loses all power i will hold it wide open and it only idles at about 1000 RPM then out of nowhere it gets power back put it in gear and its gone it is like the carbs are flooding while riding but i will have it wide open and it will still do it when riding or will do it with just regular riding please help....
AnswerMight be a couple of issues here.
Not starting on electric starter probably means the battery is worn out. Depending on how old it is, look to replace it but definitely check its electrolyte level and recharge it.
Bogging down after 6 - 7 minutes sounds like the petcock isn't operating correctly or the float valves are dirty. Make sure you have the petcock set to the ON position. Test that it flows fuel and doesn't leak by taking the tank
off and attaching a hose to it:
Set to PRI - it should flow
Set to ON - it should not flow, suck gently on the vacuum line, it should flow. Any gas leaking in the vacuum line?
Set to RSV - it should behave just like ON
if any of these fail you need remove your petcock and clean the screen. You may need to rebuild your petcock if gas is leaking in the vacuum line.
If this doesn't fix the problem, it could be the float valves are dirty (this requires a carb teardown to fix). Another possible cause may be the tank cap vent is blocked - but this wouldn't be a problem after just 7 minutes.
Do you have an inline fuel filter? Check if its dirty. Also make sure its routing correctly and oriented vertically between the carbs.
