Another Carb Question

[marker2001]

Bike - XJ1100J
I have cleaned my carbs and the bike only idles while the choke is on. I put the idle screws 1 1/2 turns out from closed as I found in another carb FAQ.

My question is - Where do I look first?
Other documentation on this site leads to the idle screws but they don't seem to change anything. If I take the choke off, the bike dies unless I give it alot of throttle.

Any suggestions?

Thanks in advance!

[Jeff]

There are plenty of threads on the forum concerning idle problems.

Check to ensure that the needle tips are not broken off in their bore.

When you cleaned the carbs.... did you tear it down including all the jets.... especially the pilot jets?

Did you attempt to adjust the idle speed adjuster knob?

Just a few little things to check.

[Mike Hart]

Had the carbs off to clean them... I'm guessing it wasn't running right before you did that, otherwise why do it?

As mentioned, check the needle tips. Also, did you synch the carbs? Or use the 'bread-tie' method of pre-synch?

It could also be a fuel delivery problem, not in the carbs at all...

You do know that you need a YICS tool to synch the carbs on an XJ? (there is a tip about that, you can make your own tool)

Good luck, keep us posted....

[Ken Talbot]

The pilot screws you adjusted control the fuel-air mixture at low engine speeds, but they do not control the idle speed itself. That is set by the throttle screw as seen here:
[IMG]/forum/images/tips/20030820-dsc02235.jpg[/IMG]

You will find it between carbs #2 and #3, "way in underneath". It's actually quite a nasty place to get to if the engine is warm.

[Bud Manley]

Thanks for that pic. Hell i didn't know this bike had one. Cool. What RPM is standard for idle? mine runs between about 1200 and 0. idles like **** until really warm

[beechfront]

i may be wrong - but i'd guess most of these bikes don't idle well or at all when cold and with choke off. the only times i haven't had to use the choke when bike is cold when it's 100+ degrees out - and that's not very often.


will it idle without the choke once it's warmed up?

[Ken Talbot]

I set my idle at about 800-900 rpm. SWMBO likes hers set a bit higher, about 1100.

[Mike Hart]

Ken obviously has his carbs well tuned, a lot of XS's don't like idling under the spec of 1100 rpm

[marker2001]

To answer some questions - the carbs were cleaned to get out the 10 yr old gas that was in them (yes, 10 yrs +). Don't ask . . .

The bike does not idle (off choke) period - warm or cold.

The carbs were torn down including the jets - all of them, except the two pressed in ones - one for air intake and one in the float bowl.

I have not synched the carbs - Maybe that's next - the carbs were not disassembled to the point of changing the original synch settings.

11000 original miles.

Thanks for all the replies . . .

From what I read here - the pilot screws combined with the throttle screw control the idle and that is what needs tweaking.

[Mike Hart]

with 10 yr old gas, how can you assume the old synch, if it ever was, is still good? Synch your carbs, even if you don't have a synch tool, use the bread-tie method. It will get you really close, even without the YICS tool to do the proper synch.

[Jeff]

My old 78 idles at around 850 cold and climbs to 1000 when warmed up. If I set it that low... it will idle as low as 500.