Running smooth- FINALLY!

[joelthebiker]

Ever since I bought my C10 about a month ago, I noticed that it ran rough below 3000 rpm.  The carbs were rebuilt and tuned before I bought it(have the receipt to prove it) and I figured that was just the way these bikes run.  Well, last night I took a look at the idle air screws on each of the carbs.  They were all set differently, from 1 turn out to as much as 2 1/2 turns out.  Assuming this couldn't be right I returned them all back to the stock 1-1/2 turns out.   What a difference!!  She runs smooth now!  Its like a completely different bike!  Bought a set of vacuum gauges to balance the carbs, but its running so well, I might wait til spring to sync them.  Now I just need to fix the right foot peg mount I broke off today when I tipped it on the crash bar because of wet leaves in the driveway.  It probably wouldn't have broke if the bottom screw hadn't fallen out long ago(didn't notice it missing because it attaches from the back side and cant see it).  Oh well, ordered a new one from bikebandit.com and should be back in business by mid week.  Not many nice days left here in upstate NY.

[George R. Young]

If it's any consolation, mine came from the factory (little plugs still on) with the screws set all over the place. The symptom was misfiring on deceleration. As you did, I plunked them all to 1 1/2 and things have been fine since.

Probably even fewer good riding days left in Ottawa, although yesterday was tops.

[Outback_Jon]

Not many nice days left here in upstate NY.

Yesterday was a great one, though.  I met up with a friend and we rode in the Bear Mountain area.  (He's from Long Island, I'm from Catskill area)  I got to watch him wipe out, and got some of it on video.     He's OK and the bike is just a couple of easy repairs from being OK.  He was able to ride back to LI, but was kind of shaken up.  Wet leaves and new pavement contributed to the crash.  Wearing gear and luck contributed to him being OK. 

Did the you get a ride in before the footpeg broke?

[T Cro ®]

If it's any consolation, mine came from the factory (little plugs still on) with the screws set all over the place.

If I recall correctly the carbs are set at the factory while hooked up to a flow meter and set accordingly; not even sure if there is an engine involded...   

[Steve in Sunny Fla]

I believe you're correct T. Over the years I've done adjustments via ex gas analyzer, idle drop, and a static setting. I have settled on static setting of 2 turns out as the best / easiest. It may be a bit richer on a cylinder here or there, but the end result is a stronger, more reliable idle than the other methods produce. HTH, Steve

[joelthebiker]

I did get a short ride in before I broke the peg off.  Rode it home with my foot on the passenger peg.  That would have been much more difficult if it was still running rough at low speeds.  The Clymer manual says the factory idle air settings for my bike are 1-1/2 turns out.  My engine seems to like them that way.

[MAN OF BLUES]

If I recall correctly the carbs are set at the factory while hooked up to a flow meter and set accordingly; not even sure if there is an engine involded...   

it's not.
the engine that is, the carbs all came from bins,preset on fixture, and assembled into a rack. some were 2 turns out, some were 1/8 turn out, I have seen combo's on a rack between almost totally shut off, and 3 turns out, with the plugs installed... and that's just the way they shipped...
now, fast forward, and pull the plugs out, turn them all in, and back them out 1-1/2, to 2 turns, keeeping them equal, and you will find nirvana...
after a rebuild using the K&L needles and seals, back them out 2-1/2 turns, or slightly more.....the taper on the K&L kit's needle is different than the stock one, and needs a bit different adjustment parameter.    I only did about 20 of those...Bubba can tell you more, as he does it more frequently than I.

[Outback_Jon]

Just how difficult is it to pull the plugs out so you can adjust the screws?  Can it be done with the carbs on the bike?


I want to pull my carbs and send them off to Steve in Sunny Florida anyway, but if I don't get the chance this year, I'd like to at least set the screws.

[joelthebiker]

you will have to remove to carbs to remove the plugs.  They need to be drilled out.

[Outback_Jon]

you will have to remove to carbs to remove the plugs.  They need to be drilled out.

That's what I thought.  Guess it will wait until carbs come off to go to Florida.

[Steve in Sunny Fla]

You can drill them out while the carbs are on the bike, but you need to be careful about it. You'll need a long drillbit, like 12" long,and about 1/8" dia.  Drill through the side of the pilot air screw housing, at the VERY bottom. it's not pretty, but it can be done. HTH, Steve

[Outback_Jon]

You can drill them out while the carbs are on the bike, but you need to be careful about it. You'll need a long drillbit, like 12" long,and about 1/8" dia.  Drill through the side of the pilot air screw housing, at the VERY bottom. it's not pretty, but it can be done. HTH, Steve

I have an extension (from doing a Bafflectomy) that would work for the length.  But I think we'd both be happier if I pull the carbs and send them off to you.   

[jklhill]

I drilled mine out with a 90* angle drill adapter and a stubby drill bit. It was a tight fit but got the job done.

[Summit670]

I too was thinking 90 degree drill needed and stubby drill bit if doing while carbs are on the bike.   With carbs off bike, very easy to take small bit to poke a hole, then you can jab the end of a small nail in there and pull the nail sideways and the plug will pop right out.  The plugs are just an aluminum disk.  Once out, they go back in real easy if you want to help keep the holes clean, not that they would ever get dirty.

As an alternate, when I first removed my plugs, I drilled small holes and screwed sheet metal screws in and used a plier to pull them out and was surprised how easy they came out.

[gtr1000]

Guys, if you drill the blanks/covers in-situ, what's the distance between the blanking caps and pilot screws?

[Steve in Sunny Fla]

Guys, if you drill the blanks/covers in-situ, what's the distance between the blanking caps and pilot screws?

not far, and when the bit gets through the aluminum if you hit the screw the soft brass drills really easily, which ruins the screwdriver slot and makes removal difficult and adjusting impossible.  Steve

[timsatx]

I think I will wait till I pull the carbs off to do an ultrasonic cleaning to work on the screws. I will be interesting to see what they are adjusted to.

[gtr1000]

not far, and when the bit gets through the aluminum if you hit the screw the soft brass drills really easily, which ruins the screwdriver slot and makes removal difficult and adjusting impossible.  Steve

Thanks Steve. I'd better watch your vid a few times in the next few days/weeks and pluck up the courage to pull the carb rack  .