Smells like gas

[RiderX]

Ok all, I am not sure what to make of this. I have ridden my '98 regularly and year-round for 5 years now. I had the valves adjusted at 24k about 4 years ago and it now has 40k miles. I was on my longest ride in a couple of years on a trip from Boise to Challis three weeks ago. I had filled up with Premium non-Ethanol fuel before leaving figuring it would help with the increase in altitude. I got to about 30 miles outside of Stanley (about 100 miles) and it started to surge between 65-70mph. Above or below it seemed fine. I topped her off at the station in Stanley with Premium, took a 20 minute break and got back on. It was now surging at all speeds! It seemed to clear up at higher RPMs, but I was hesitant to go much faster than 50mph on the twisties between Stanley and Challis which was only another 58 miles.
I decided I must have gotten some bad fuel and picked up some Lucas Oil fuel treatment at the local NAPA. I also swapped out the gas filter which I had swapped out for an external see-through filter several years back.

I let it sit overnight and started it up the next morning. It continued to surge at 25 through town and all the way up to 75 on the highway. I turned around and found a local mechanic in town. He listened to it and said "that ain't fuel, that's spark!" We pulled the spark plugs out and all three of them were black. He said "wow, with 40k miles you probably have rings going out." We put in a new set and the surge disappeared and I rode it back home. It continues to run a bit rough and smells like gas at the exhaust, not like burning oil. There is quite a bit of dry, black soot coating the inside of the exhaust pipes. It has some trouble starting when it is cold, even when the air temps are 80-90 degrees outside and I have to use the choke until it's warm. Any thoughts or suggestions would be greatly appreciated!

[RiderX]

I forgot to add that I get quite a bit of white-ish smoke when I am starting it cold and a bit when I blip the throttle.

[JetdocX]

24,000 miles between valve clearance checks?  I think I've heard enough.

[RiderX]

You mean 16,000 miles? I wouldn't think it would be quite there yet.

[rybes]

white smokes normally just steam. so id keep an eye on ya water lever n get a compression check done to make sure its not the cylinder head gasket

[nightrunner]

Also, if you are smelling gas it may the float valves have a bit of dirt in them (one or more) and allowing the gas level to get too high in the bowls.

[JetdocX]

You mean 16,000 miles? I wouldn't think it would be quite there yet.

My 98 went from spec clearance to negative in 5000 miles.  I hope that's not the case for you, but it wouldn't hurt to check the valve clearance since you're going to be pulling the carbs anyhow.

[Joe Bates]

I filled mine with REC 90 (90 octane no ethanol) and it ran fine coming home.
Let it sit for a couple days and it ran as you described.
Ruff to get to idle after starting also.
Rode it 56 miles and it cleared up.
Runs good now.
A little more cold blooded to get started then I remember tho??
Haven't put a lot of miles on since it happened, 2 tanks.
Mine always smells like gas.
Love it tho. Fixes itself, most times.