Gummed up valve. Possible causes?

[flyboy]

I'm doing a carb rebuild and I noticed one gummed up valve:

All other valves for all other cylinders are as clean as the one on the left - this is the only gummed up one. So I'm wondering of the following:

1. Could this have something to do with my carb issue (leaky fuel needle valve on one carb, which I just finished replacing)
2. If unrelated, what are common causes for this type of a build-up?
3. What effects would ignoring this issue have on the engine? Short term? Long Term?

Background info: 2002 Katana 750 with 40,000 miles. Valves adjusted and cleaned by a mechanic about two years ago.

I am hoping I can get this bike put together in time for my ever looming solar eclipse trip to Oregon next week, but upon discovering this today, I'm starting to get nervous about putting 2500 miles on this bike if this means pontential to mess up on the road. Any help or words of wisdom are welcome =)

[rperry03]

Valve seal possibly leaking. Other possible causes, can you do a leakdown test? That will confirm that the valve is sealing and almost certain that its not a bent valve or guides in spec

Oh...ignoring will foul up your plug. Have you pulled the plug and check It? If plug not fouled up terrible clean everything up and keep an eye on oil level.
Does your air filter and/or housing show any of That?
How's the breather hose? Given that its only 1 intake valve it's most likely probably not a breather issue or carb issue, both would be gunked up

[92xjunker]

Smoking on startup or from a standing idle, would been a valve guide seal. Generally rings would cause that. A compression test and a leak down test would confirm rings. Being that it's only 1 I would assume valve guide seal. But, other issues could also show this. Such as bad fuel on a leaking carb.

[flyboy]

Hmm, is it safe to assume that even a simple thing like a valve guide seal on a Katana can't be bought at the auto parts store?

Asking cause I have to make a decision to either:

1. Wait a week for the part to get shipped and miss the solar eclipse
2. Buy a new set of seals at the auto parts store and be done with it
3. Say "screw it", close it up, and simply deal with it 2500 miles later after the eclipse trip is over

[92xjunker]

If it isn't smoking, f-it....keep going

[rperry03]

Say screw it, you're going to have to change the oil again when you get back anyway.
.......but, at least pull the plug, take a look at it, and clean or replace if necessary

Doubt autopart store wouldn't have them, Suzuki dealer probably wouldn't keep them in stock. If they are cheap enough order a set, but I would do a little diagnosing first

[flyboy]

Badass! Thank you, everyone