I just finished a move from the prairies East.  As a result of different factors, I hadn't been able to ride the bike for almost 5 weeks.  so the bike sat there with the same gas, untreated in the tank.  I took the bike out yesterday and today for a quick ride.  Each time it starts right away and runs well on choke.  Take the choke off and it drops down to about 500rpm.  As the motor warms, this doesn't change.  I don't think it's the idle adjustment, I'm thinking the gas plugged the idle circuit.  Any recomendations on an additive that I could use to clean the pasages?  I will be putting the bike into storage on the 15th of this month, with the appropriate amount of stabilizer in the tank until next Spring.  As a note, I used Stabil last year and had no issues on start-up this past Spring  Bike is a 2006 C10.  Thanks in advance for any hints

I wouldn't think 5 weeks would cause anything, but it does sound like your idle circuits are plugged.  Maybe though it sat 5 weeks, the fuel in the tank was older yet.

Sea Foam is what a lot of people swear by.

I'd drain the float bowls into a white plastic cup a few different times to see what comes out, after you treated the tank fuel with Sea Foam and run it at least 20 minutes or so to get the treated fuel in the carbs, then give it a few days in the carbs to do it's thing, then drain the bowls a few times, maybe allow a few days between drains.

Thanks for the reply, I'll see if I can scare some up around here.  Put fresh gas in and I've ridden about 70kms so far, now it will idle, somewhat roughly at about 500-750, but is still rough at idle and just off idle.  But at least now there's an idle!  Kind-of.

 Your idle should be set at between 1000 and 1200 rpms

Thanks for the reply, I'll see if I can scare some up around here.  Put fresh gas in and I've ridden about 70kms so far, now it will idle, somewhat roughly at about 500-750, but is still rough at idle and just off idle.  But at least now there's an idle!  Kind-of.

You need to be setting your "hot" idle a bit higher at 1,050 to 1,150 RPM which is pretty close to the factory specs....

Only when these engine and carbs are very well tuned will they idle well at less than 1,000 RPM.

As to STABIL I use it on a semi regular basis as my bike routinely sits for 4 weeks at a time and when I'm busy with my off-ship life sometimes it will sit for 5 to 10 weeks at a time and I've avoided cleaning my carbs all but once since purchase in 2002

The issue seems to be the combination of 2 different events, that caused this. First, the bike sat, with unknown aged fuel, for a long period. Second, during that period, you say you moved, and likely the bike was moved in a manner that stirred up all of the loose and microscopic rust particles in both the tank, and possibly the float bowls.
When you attempted to start the bike, these migrated into the low speed circuit. drain the bowls. Unfortunatly there is NO additive that will disolve the grit in the idle circuits, to get this part fixed requires disassembly, and agressivly blasting the circuits out using Gumout, and air. The Idle, if it was idling back before the storage, at the correct rpm, will return to where it was, adjusting the idle adjustment now will not acomplish the goal.

simply removing and reinstalling a tank on a bike that sat will stir up the gack enough to cause this syndrome. I always drain fuel into a can/jar/clear pop bottle when I replace the tank after a removal, to insure I get out the sludge that sits at the bottom removed before hooking the fuel line up to the carbs.

The pilot, or secondary, jets are all of 11 thousandths of an inch in diameter. Worse, they sit in a tube well above the fuel, so that when the engine isn't running the fuel drops back down away from the jets. If the jets are open -- all .011" of aperature -- fuel flowing through will help disolve any deposites from the last evaporation. If the jets are plugged, then fuel isn't going to disolve the deposits -- and additives aren't going to do so either.

The pilot, or secondary, jets are all of 11 thousandths of an inch in diameter. Worse, they sit in a tube well above the fuel, so that when the engine isn't running the fuel drops back down away from the jets. If the jets are open -- all .011" of aperature -- fuel flowing through will help disolve any deposites from the last evaporation. If the jets are plugged, then fuel isn't going to disolve the deposits -- and additives aren't going to do so either.

  HMM, seems like I've seen this before... except I wrote that the pilots are .013". Nice to know someone actually reads my dribble!    Steve

  HMM, seems like I've seen this before... except I wrote that the pilots are .013". Nice to know someone actually reads my dribble!    Steve

   Yes I do read it. I'm sooo lonely.

Well I had to learn it somewhere -- I just wish I could start to learn things the easy way once in a dang while!
Next thing you know, I'll be buying a new set of air box boots so that it doesn't take me days to push the blasted things back in.
Then again, I read good things about the soon to be Trophy...

Thanks for all the replies and information.  I will be storing the bike in a couple of days for the winter.  Insurance from Alberta expires on the 15th of this month and I don't want to safety and all that right now, so the carbs will become a winter project.  Remove, clean reinstall, then next year I'll do the safety and get everything working tickety-boo!  It runs now ok, just a little finnicky leaving stops and all, until the off-idle problems stop and the revs go up hight enough, but once the rpms are up, she still sings!!