Why To Check Valve Clearance

[datsaxman@hotmail.com]

The obvious reasons were valid...the exhaust clearances were almost criminally tight.  I didn't even measure the intakes after I noticed...

That the intake cam was off by one tooth.  This is not a typo. 

My first job as a mechanic was at a Kawasaki/Ducati/Triumph shop.  After desmos existed, and before the Britbike labor meltdown.  Yes, some time ago.  It was a bit of a trip down memory lane, as I have not had the lid off an inline four in a *few* years.  Once upon a time, I saw them just about every day. 

Bought the bike 14 months ago with 12000miles.  Now has 38383 miles, and boy was I shocked to see the mis-alignment marks.  Yes, the cam gears had to come off...yes, I got to play with the auto chain tensioner...yes, one bolt had to come out of the blockoff plates to get the lid out...yes, I remembered how to trick the cam chain slack into ending up in the right place so the whole thing ended up in sync when it was reassembled...yes, my cams are slightly pitted...yes, I did the adjustment one valve at a time...yes, I did my own version of SISF's cam gear mod...by hand...yes, I set the clearances at the big end of the range...yes, yes, yes.

Oh, and the thing runs SO much better from 3000-5000 rpm I can hardly believe it.  It ran fine before, but it is quite a bit more responsive at small throttle openings.  Go figure...

[MAN OF BLUES]

 

[datsaxman@hotmail.com]

Yeah...intake cam was advanced 10+ degrees.  Pass the popcorn...

[Strawboss]

Wow. Interesting. I didn't think it would run all that good with it that far off. Its like a new bike now huh?

[MAN OF BLUES]

 

[datsaxman@hotmail.com]

Well, I didn't expect anything was wrong when I got it...go to the guy's house, hear it run (nice and smooth), take it for a cruise in the Sierras (smooth and good, not much power down low).  My first ride on a Concours.  Gave the man some $ and rode home.  I used to work at the Kawasaki shop, so I have ridden hundreds of Kaws from the earliest to early 90s.  Felt like a cross between a KZ650 and a Z1.  Hey, I have been riding a Buell 1203, so any Concours is going to have a lot less bottom end.

The cam timing is not so extreme that valves were getting bent or anything.  Compression is good.  And I don't feel the need to rev it up past 8,000 or so to get where I am going most days, so no problems.  But yeah, the thing pulls a lot better down low.     

Cam timing is a compromise, and it is a better compromise now.  Folks like to think that if something is ANY amount of out-of-spec, disaster is imminent.  Not always. 

I sure was shocked to see the mis-alignment marks, though.  Rolled the engine through a few cycles confirming it, covered it up and went inside for a drink, came back out to confirm, said DAMN a few times, and started pulling cam gears.  Compression test once it was all back together.



saxman