Motorcycle Repair: white smoke, honda cx 500, valve seals

Question
chris,

I bought a 1979 honda cx 500 custom and the bike started to smoke white and bike shut off, now bike will not run it attempts to start but just wont make last effort, please advise possible problem.  

Answer
Hi Kevin.

Well, I have good news and bad news.

First the good news;
The bike is repairable.

Now the bad news;
The bike suffers from one or more of the following problems;

1) The pistons need work (rings cylinders need boring, etc.)

2) The valves are so far out of tune that they are letting in oil and not much else.

3) The valves/valve seals are fried.

To see if the pistons and cylinders are the culprit, use a compression tester and see if what you get matches what the specs in the repair manual say the compression should be.

If the compression is out of spec, then you need to get the bike into the shop.

If the valves/valve seals are fried, then they need to be replaced.

Let me know what you find.

Good luck and ride safe.
FALCON