I own a 1979 Kawasaki KZ650SR. I bought this bike in Nov. 2018. The bike has been taken care of for the most part as it is in good condition for being 40 years old. However, as the title states, I realized the bike was lacking power and noticed the exhaust pipe from the 2nd cylinder was not hot due to oil on the plug.
I've noticed oil leaking from the engine. I was hoping it would only be the head gasket but if that was the case, wouldn't all cylinders be having issues?
Other than the occasion lack of power, sometimes the bike feels like it's firing on all cylinders, as there's a significant increase in torque, but the pipe will still be cold. It idols fine at start up but will stall if I don't keep on the gas while riding (I've already adjusted the idol control). I have the original owner's manual and have read it from front to back (twice) and am still unsure. I'm hoping someone will be familiar with this issue so I'm not doing guesswork.
Thank you for taking the time to read this and all replies are appreciated,
Do you have check #2 cyl. has a spark on the spark plug?
The oil you see on the spark plug could be unburnd fuel cause by a broken spark plug.
Change/Switch #2 and #3 spark plugs and look if the issue following now on #3 cylinder.
If the oil leak is around the area where the tachometer cable attaches to the engine it can be easily fixed be replacing a couple pieces in that attachment collar. This is a common problem, but fortunately it's easy and inexpensive to fix.
Regarding the oil on the spark plug - what spark plugs are you using? Also, are you positive that the carbs are squeaky clean and properly adjusted? Ed