I really need help!

[mrtkayak]

Just bought a 79 xs1100 special.i put new battery,change oil and clean the carb just to find out that the pilot jet has 2 42.5 and the other 2 at 45.totally clean the carb but when idle,maybe a couple of seconds it went up to 4000 rpm.it wont stay on the normal idling.pls need your expertise.

I guessing here: maybe the bigger pilot jet let too much gas on the float ad thats why idle went up all of a sudden and stay at 4000

[James England]

Just bought a 79 xs1100 special.i put new battery,change oil and clean the carb just to find out that the pilot jet has 2 42.5 and the other 2 at 45.totally clean the carb but when idle,maybe a couple of seconds it went up to 4000 rpm.it wont stay on the normal idling.pls need your expertise.

I guessing here: maybe the bigger pilot jet let too much gas on the float ad thats why idle went up all of a sudden and stay at 4000

I believe that the two inner cylinders often have different sized jets, although someone will soon respond to you if I'm wrong. I don't think that would cause the revs to go so high and stay there.

You say you cleaned the carbs. How far did you go with it? It's possible that you haven't done it correctly. I've been there myself!

[mack]

Carbs

Your pilots should all be 42.5, The compensation for the inside cylinders is usually done with the emulsion tubes, or main jets. If the carbs are in fact the early style carbs the emulsion tubes should have #266 and 301 stamped into them. The ones with the least amount of holes are for the inside carbs.
Check to see the throttle cable routing is correct and that the butterflys snap all the way closed before you start it. You'll hear an audible click.
I'm sure you know to bench sync the butterflys before installing the carbs right. Failing to do that is the main culpret for hanging idles.
The next biggest issue is having one of the intake boot clamp screws hitting the throttle shaft and holding it open.
And lastly, this is the one you don't want to hear. Remove the carbs again and clean them properly as per the tech tip. "cleaning carbs 101"

[trbig]

While I agree that all the pilots should be the same, a motor that starts revving at idle is generally needing a good carb synch if the cables are all free. A bench synch should get you close to where the bike will start, but you will need a more fine tuned synch after that.

[hondakid11]

if your valve are too tight, that will cause the engine to idle high as well.

[mrtkayak]

I believe that the two inner cylinders often have different sized jets, although someone will soon respond to you if I'm wrong. I don't think that would cause the revs to go so high and stay there.

You say you cleaned the carbs. How far did you go with it? It's possible that you haven't done it correctly. I've been there myself!

That s what Im thinking too.Took all the main jets, pilot jets, checked the diaphrams (looks ok,no tear or holes ),pin taken out and the floater, discovered that the previous owner repaired one of the post that holds the float, not welded but re-attached by a wire w holes.needle cleaned and check spot and clean every part that i can think off.

[mrtkayak]

Your pilots should all be 42.5, The compensation for the inside cylinders is usually done with the emulsion tubes, or main jets. If the carbs are in fact the early style carbs the emulsion tubes should have #266 and 301 stamped into them. The ones with the least amount of holes are for the inside carbs.
Check to see the throttle cable routing is correct and that the butterflys snap all the way closed before you start it. You'll hear an audible click.
I'm sure you know to bench sync the butterflys before installing the carbs right. Failing to do that is the main culpret for hanging idles.
The next biggest issue is having one of the intake boot clamp screws hitting the throttle shaft and holding it open.
And lastly, this is the one you don't want to hear. Remove the carbs again and clean them properly as per the tech tip. "cleaning carbs 101"

Ill double check tonight ,specially the cable and butterflys ,that might be the culprit.if not i have to take down the carbs again.Thanks

[mrtkayak]

if your valve are too tight, that will cause the engine to idle high as well.

Ill make sure that i did the right thing first on the carb before tackling the valves.Too scared to touch this..but thanks all reply are helpful..thanks GUYS!

[motoman]

Ill make sure that i did the right thing first on the carb before tackling the valves.Too scared to touch this..but thanks all reply are helpful..thanks GUYS!

If pilot jets(larger number to center two cyl.(#2/#3) are correct, the slides with the metering rods can easily be removed without pulling carb bank. Just seat and tank removal is all that's needed.

[BA80]

Wrong jets Brant.......pilots should all be the same. Mains are richer on 2 and 3 on a few years.

[hondakid11]

Ill make sure that i did the right thing first on the carb before tackling the valves.Too scared to touch this..but thanks all reply are helpful..thanks GUYS!

just remember youre going to have to do it sometime or another. its part of the maintenance.

try one size bigger on the pilots. i have to run mine a little rich on the pilots to keep it from over reving.

[BA80]

i have to run mine a little rich on the pilots to keep it from over reving.

Now THAT'S funny, I don't care who you are.

[hondakid11]

hahah i thought so . actually i got mine right where it needs to be with the colortune and she still ran a little hang idle until i did a valve job. then she ran smooth. im running k&n pods and open pipes with 45 pilots and 145 mains.

[LoHo]

My tiny, specific experience has been that vacuum leak/leaks are the main rev up problems. Make sure the vacuum plugs are sealing and the advance hose and vacuum feeds to the carbs are not cracked.

[mrtkayak]

My tiny, specific experience has been that vacuum leak/leaks are the main rev up problems. Make sure the vacuum plugs are sealing and the advance hose and vacuum feeds to the carbs are not cracked.

Well I need to check this too. By the way where and what is a vacuum plugs he he he.I need to get a manual for this bike.Thanks bro!!!