Are these dirty or normal? (valves)
 

Took the exhaust off last week and welded in some bigger Bungs for sensors for getting the bike Dyno'd. Thought id take a pic and see what the state of them was. Thing is im not sure, looks like a fair amount of build up to me but is that normal?

Taa

http://www.apriliaforum.com/forums/a...1&d=1298985464

http://www.apriliaforum.com/forums/a...1&d=1298985477

Re: Are these dirty or normal? (valves)
 

got a bigger picture?

Re: Are these dirty or normal? (valves)
 

Doesn't look unreasonable to me. Depends what it's done really.

Re: Are these dirty or normal? (valves)
 

Coming upto 37k miles.

Is it something that will improve if the A/F is brought more inline? Or does it not matter?

Re: Are these dirty or normal? (valves)
 

They look normal for 37k Miles, is that oil at the top of the whitish build up?

You will get build up whatever the AFR, remember your burning stuff in those cylinders.

Re: Are these dirty or normal? (valves)
 

need to put my glasses on to see that

Re: Are these dirty or normal? (valves)
 

It does look a little like that could be the case with oil, it looks a little erm, moist. I've never noticed any blue smoke or the oil level dropping at any silly rate. It might just be a tiny weep through the guides.

Cheers, for the info anyway. Im still learning :)

Re: Are these dirty or normal? (valves)
 

Just for info, valve stem seals are metering devices, they pass a very small amount of oil down the guides for lubrication, they are not meant to be perfect seals. The angles of the lip (on top and underneath) are carefully designed to achieve the right metering, and will work reasonably consistently even with some wear of the seal and also with the range of pressure differentials across the lip.

A small hint of dampness is not unusual since there should be a trace of oil in the guide.

This one shows the angles at the top lip, and intersetingly it also has a "gas lip" below the top one which is there to stop high pressure gas blowing back up the guide in pressure charged engines. (SV seals won't have this feature).

http://www.tappsa.co.za/images/july_...Stem-Seals.jpg

Re: Are these dirty or normal? (valves)
 

Ah cool. Thanks for the info Embee! Something else I didnt know :)