Motorcycle Repair: 1971 honda sl350, carburetor rebuild, engine smoking

Question
im working on a 71 sl350 and at 40 miles an hr it falls flat and loses power, im not sure about my valve clearance or my points adjustment, ive got good spark and fuel flow my compression reads to about 170-175psi, ive cleaned and adjusted the carbs but it continues to smoke and run rough

Respectfully
Kc

Answer
It sounds like its running out of fuel.
Fuel levels may be to low. Check the air filter to see if its dirty. A dirty Filter can cause a choking effect. Also the air jets or carb bowl vent holes may be clogged.
What color is the smoke. Black smoke means its running to rich, to rich of a fuel ,mixture.
Blue smoke is oil. which could be a number of things. Valve guides. Broken oil ring.
Also a rich fuel mixture can foul a spark plug in 20 minutes.
If the smoke is not blue and there is not oil in your air filter, I would
suggest a professional carb rebuild. Visit my website www.viragocarb.com.
I rebuild all makes of carburetors.
Also do a search on a tool called a (Gunson Colortune Tool)
Its helps you set your fuel mixture Perfect....