1st valve adjustment/inspection

[belfastguzzi]

using large flat blade screwdriver thru timing inspection window to gently lever flywheel round to alignment marks.

KB, have you been able to see alignment marks on the Scura flywheel?

[jrt]

haha...fixed it.  can't type.

 

and Brian can be gentle on my brain as he explains the valve thingy....

I think we were typing at the same time.

Let's see if I can do a surrogate Brian.

Valves have certain timings associated with them. They need to open and close at particular times during the revolution of the motor. This is dictated by the profile of the cam. Valve lash is just the space that is set between the valve and the rocker (on our bikes) that allows for valve train expansion. As the motor heats up, the cam follower and pushrod heat up, expand, and close the valve lash to something like .001 or .002. So the valve lash is just the space that allows the valve train to expand to hot running conditions.

Loose valves give a little better low end performance, at the expense of top end. If your valves are set too loose, then they make noise, which is a direct result of the valve train bashing against itself. You can have problems as a result of too much valve lash, usually the valve train (seats/valves/rocker heads/cam follower/cam) shows early wear because parts beat on each other.

Tight valves give a little better top end performance at the expense of bottom end (hence the poor idle that people sometimes mention). If valve lash is too tight, then it can lead to more insidious problems than too loose valves, because they are not as distinct and they don't make that much noise. If lash is too tight, valves open early and close late. At the extreme, as the motor heats up and the valve train expands, the valves may not close at all- or may even collide with the piston. If valves are set just 'chronically' tight, then you can make trouble because valves may never fully seat when they get hot. This can result in loss of compression (again an extreme case). Valves also rely on setting in the valve seat to dissipate heat (esp. the exhaust valve). If they don't set fully or correctly, then you can burn a valve from overheating.

So neither extreme condition is beneficial; set them correctly for happy tappy valves.

Hope that helps.

Jason

[al_roethlisberger]

 

 

 

What up with the heading of this thread..."tighter than a etc".   Why add the phrase, and why hasn't a moderator found this insulting?  Al, have the last word please this time...but this time only

 

 

Heh, well I'd have to defer to Docc methinks.... as the forums I "moderate" are pretty low key, and haven't really given me the experience to handle such a provocative issue

 

 

 

... anyway, "virgin" is pretty euphemistic after all

 

And who's to say he wasn't just saying she's frugal?

 

 

 

 

[Guest dkgross]

Thanks JRT!. I actually understand that. THAT"S scary...

 

well..Until I hook up with one of ya'll, I'll let Micha and Jason set them up however they feel is best I do notice that everything they adjust stuff, the bike feels 'tighter and stronger'.

 

Just a 'butt feel' kind of technical analysis on my part...