Motorcycle Repair: KZ550 exhaust smoking, kawasaki kz550, hi lex

Question
Hi Chris - I have a few questions about a 1983 Kawasaki KZ550.  1) It runs well, but makes noticable white smoke from the exhaust.  A friend of mine told me that means the gas mixture is too rich.  Is that true?  How can I adjust that?  2) It takes forever to warm up.  When it's warmed up it's fine, but it takes about 5 minutes even when it's nice out.  It stalls if I give it gas before it's warmed up.  Is that related to the gas mixture as well?  3) One of the bolts on one of the clamps where the pipes connect to the engine is broken.  So there is only one bolt holding it on, and a little exhaust leaks out of there.  Is this a serious issue?  I heard it was.  What can happen to the bike?  How can I replace that bolt?  It seems like the engine has to come off and be opened up, which seems like a lot of work for a little bolt.  Thanks for your help!  

Answer
Hi Lex.
 As far as the white smoke, that is oil being burned off.  If it were fuel, it would be darker or black.  The fuel mixtures are set at the factory and unless that has been tampered with (it would be obvious if it had) then there is nothing wrong with the mixture setings.  However, a good carb cleaning may be in order if the bike sits in storage for long periods (seasonal) without being used.

As far as the other problems, they are all related to that missing bolt.  That can create some serious issues over time, but, depending on access to the bolt and bolt hole, it can be fixed with the engine on the bike.

If I am understanding you correctly, the bolt in question is one of the header bolts.  Those are threaded at both ends.  One end goes into the engine while the other one goes into a nut that  holds the header pipe clamp in place.  An exhaust leak at the header end of the header pipe can cause severe running problems.

Now if this is the header pipe mounting bolt, then you need to remove the old one.  This can be done by pulling that header pipe and unscrewing the bolt from the hole.  If the bolt is broken off too far down, then you will need to drill it out and retap the hole.  Let a pro do it if you have never done this kind of thing before.  After that, replace it with the correct bolt for that application.  If it is an easy removal, then just get one from the dealership.  They will probably have to order it as they are not common use bolts.  If it requires drilling, then the mechanic will get the right bolt in there.

Good luck.
FALCON