Is my bike suddenly cooked??

supamandasun

CB750 Member
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Hudson, New York
Bought a 1980 CB750F in April. Would hardly run/idle. New spark plugs, coils, CDI, rotor, stator, reg/rec., valve clearances adjusted to .005, cam chain tensioner adjusted as well. For the past few weeks it'd been running smooth and strong. This past week something was amiss- intermittent backfiring, dwindling idle, stalling here and there from a loss of power (open throttle, hardly a response). Whenever it stalled, I'd restart the motor instantly and all would seem totally fine. Made some adjustments to the clutch and all seemed well again- it would no longer lose power and eventually cut out. Tonight was different- it stalls. i restart the motor, idle dwindles. I try to take off in first gear and it stalls. Try, try, try again, stall, stall, stall. But just moments before, all seemed fine. Work order from previous owner mentions a carb rebuild had been done... 7500 miles on the clock. I'm going to pop the valve cover off tomorrow morning... no strange noises catch my ear. What on Earth should I look into here?
 
Look for a loose battery connection or dying battery. Could also check the battery ground to frame.
Make sure you're not losing spark; pull all plugs and ground them against the engine (valve cover might not work for this but you can try) while cranking the engine to verify spark.
If you're sure the air filter good, and you've got a strong battery, the carbs are the likely culprit.
 
Does it look like your bike's electrical's cutting out randomly? Mine and a few others in these forums have been experiencing loose and melted connectors at the ignition circuit.
 
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