I just had my local bike machine shop do a valve job. They found a bent valve and planed the heads. The results are awesome. But now
that I've done a little spirited riding I'm wondering about a proper break-in. Oh oh [bang]. Should I be doing the break-in procedure one would follow after a more complete rebuild? Should I be running mineral oil instead of synthetic?
I did a compression test and found that the engine was nicely balanced between the cylinders but the compression was actually down about 15 to 20 psi from the pre valve job test for the good cylinder. The results of the test got me thinking that the engine may still need to break-in. I had pulled the cylinders but did not hone them but none the less, the rings may also need re-seat since their positions on the pistons were altered. Is that logical?
I have scheduled a dyno run for today but am considering canceling until I have 500 miles on the valve job and do another valve adjustment. What do you think?
Quote from: akmnstr on August 25, 2008, 10:23:35 AM
I have scheduled a dyno run for today but am considering canceling until I have 500 miles on the valve job and a valve adjustment. What do you think?
From what I know about the valves I've lapped, mostly automotive, they are going to seal on the bench as well as they will ever seal.
I don't think there's any break in at all.
I'd dyno the thing if you want. There's nothing to lose.
Maybe the machine shop will know the answer. Or maybe they'll know someone who will know the answer.
Quote from: uclabiker06 on August 25, 2008, 12:16:18 PM
Maybe the machine shop will know the answer. Or maybe they'll know someone who will know the answer.
Dah [bang] [bang] Thanks for stating the obvious. Don't know why I didn't think of that. I called them and they said that I'm good to go.
No need for a break-in. They did say that the compression should improve in a few hundred miles. I canceled my dyno run and
will do it after the 500 mile valve adjustment.
I am excited about doing the Dyno run. I think I have been running with that bent valve for about 4 years. My engine is at last running smooth
and strong.
[thumbsup] Glad to know things are finally working out for you. Its always nice. [moto]