Topic: Valve adjustment nightmare........maybe. '78 550k

[zoo mob]

So I had my buddies over to adjust the valves on one of their bikes, a '78 550k, it had had a rather noisy engine since he got it last year. I'd assured him that doing this was no big deal and that it would be a quick,fun way to quiet his bike down. Well, we did it seemingly just as the Clymer manual suggests, .002 on the intake side and .003 on the exhaust side. I showed him how to do it on the first couple and let him do it on his own the rest of the way. Well, he rode it home and supposedly it is running like crap and wants to die, hesitates etc. What could have gone wrong here? One thought was the obvious like gas lines etc. Could an inaccurate valve adjustment cause poor running? Also, could a short ride like this cause any damage? I'll know more once I get over there in the morning to check it out. Thanks for any insights.

[OldSchool_IsCool]

Was the engine stone cold when you adjusted valves?

The gas tank had to come off, of course, so a fuel issue could have been introduced.  Does your buddy run an in-line filter that could be holding an air bubble?  M aybe the fuel line was rerouted funny such that it has a high spot or a pinch.  Have hime drain his carb bowls with the petcock ON to see if there is good, even flow through all four carbs.

[Cvillechopper]

Like Oldschool said engine has to be cold (like sitting all night) to do valves.  Metal expands with heat.  Correct adjustment to a cold engine allows the tappets to close slightly with the heat of running.  Adjusting while hot (or even warm) puts the valves more open than they should and would certainly give a poor ride home.