Motorcycle Repair: engine, right cylinder, yamaha 750

Question
hello
 I have a 1979 yamaha 750 special that I'm buying from my neighbor. He is having some trouble getting it to run ,the bike was sitting in his garage for about 2years. the issue is the right cylinder is back firing or sputting /running ruff.he has takin the carbs out and cleaned them up ,put new plugs in .did a compression test, each cylinder has 150psi and there is a spark ,any suggestions on how to get it running better  i would appreciate it thank you

Answer
Hi John.
 Considering that it is only one cylinder, there could be a short or bad connection in the wiring between the plug and power.  There could also be issues with the carbs being out of synch or the valve gap and timing being off.

 The fact that you are getting good compression at all four cylinders, says that there are no holes in the cylinders so that is not an issue.

Check those out and let me know what you find.
Good luck.
FALCON