Carbon build up on intake valves??

[GSF500]

I rejetted my carbs and when I pulled them off I shined a flashlight into the motor a notices alot of carbon build up on the valves. I plan on doing a valve job soon and would like to know if there is way to clean the valves? Should I leave them alone? and what causes this? My bike has 11,000 miles on it and it's an 07. Should I run premium gas + additives?  Thanks again for your help.

[jestercinti]

I'd leave it alone.  Just make sure that your jetting is correct, and you will be OK.

Knew a guy once that had an old VW Bug.  He swore that his engine was dirty on the inside.  Cleaned it all up and it never ran well again.  Turns out all the gunk was holding the compression...

Our engines have the complexity of a medium-sophisticated lawn mower.

[BockinBboy]

A little bit on premium vs regular gas...
http://www.epinions.com/content_2346164356?sb=1
To sum it pertaining to the GS500: your engine was designed in the 80's, it was designed for regular gas, it will not see any benefit from premium (nor do MOST cars)

Carbon build up is normal, but how much is normal?
I would suspect if you run too rich for too long, you may have more than 'normal'.  Do your plugs tell you that she's rich?
As jester says, I wouldn't worry about the build up thats in there now.  Just correct the problem that causes more carbon build up IF you have a problem. 

- Bboy

[applecrew]

I rejetted my carbs and when I pulled them off I shined a flashlight into the motor a notices alot of carbon build up on the valves. I plan on doing a valve job soon and would like to know if there is way to clean the valves? Should I leave them alone? and what causes this? My bike has 11,000 miles on it and it's an 07. Should I run premium gas + additives?  Thanks again for your help.

Just did the same thing (rejetted carbs) on my 07, but I have 64,000 miles. I also looked into the intake chamber and saw the deposits... and I'm gonna leave them alone. I think you've got PLENTY of good miles ahead of you! BTW, don't waste your money on premium. These bikes were built to run on 87 octane. I know that this will elicit a response from some... but if mine is still running well on regular after all these miles, then I say why waste your money? I have empirical data to support my claim.

Take good care of everything else, of course!

Cheers & Beers!

[GSF500]

  I won't panic......Thanks for time and I will leave it alone, Plugs look normal, I was just suprised how crusty they looked.

[twinrat]

PANIC PANIC  carbon on inlet valve seat is a sign of tight inlet valve  or valves if its both .My valve seat is clean at 18,000 miles .Carbon only gets on there if your valve is being  held off the seat even if it is only.0005 "
because the pressure is greater inside the cylinder when it fires then outside. ON high milage vehicles you will see it on the valve seat when the guides are worn as it allows oil past  which comes in contact when the valve is open and burns on to valve and seat  when hot.Hot cams are also another source of carbon on inlet valves because they are not operating in there correct rev range EG to much idling ,.