slight miss

[crodrigo2006]

I have a 1981 xs1100 with 84000 miles on it. I put new carb boots on, new plugs, had the carbs gone through and sync. when i twist the throttle wide open under 4000 rpm it misses for a moment then runs fine. sometimes its a quick miss other times it misses for a few seconds befor it straightens up.

[boyat68]

crodrigo2006:

When you say, "had the carbs gone through and sync. when i twist the throttle wide open under 4000 rpm it misses"

Can we assume that some one else did the work?

It sounds like your pilot jets are not performing correctly and may need cleaning or replacing as that is the culprit that takes the machine up to 3-4 thousand where your mains cut in due to the action of the slides. It also could mean that you have the wrong pilots in.

[boyat68]

crodrigo2006:

Another thought: I believe that your pilot tower where your pilot jets are installed has a rubber plug on the bottom just like my 80G. The pilot tower has a drilled through hole from the main tower that supplies fuel for your pilots and the rubber plug keeps the fuel from being suctioned through the bottom of the pilot tower. If this plug is missing then the pilots do not perform correctly and not enough fuel is suctioned to sustain the machine up through its medium range. Check to see if this plug is missing.

[Ken Talbot]

Right after, or maybe even before pick-up coil problems, having an XS that stumbles at some mid-range RPM before it screams like a banshee, is altogether too common. A great place to start your research on this issue would be the tech section specific to carbs. Then, try using the search button at the top of the page to look for phrases like "low speed stumble", or "hesitation", or "carb problem" and you'll find lots more threads.

The good thing is that carbs are not rocket science, no matter how intimidating it may seem at first. There's lots of guys and gals here who would have never dreamed of digging into a set of carbs. But, after some poor performance from dealers or repair shops, they have taken our advice and tackled this job themselves. With a few basic tools and a bit of time, virtually everybody can work on their own carbs. There's lots of support here if you run into problems along the way, and there may even be someone who lives close to you who can help you get started.

There is a certain satisfaction from doing this yourself, getting it right, and ending up with a 30 year old machine that will reliably pull your arms out of their sockets.

Oh, BTW - welcome to the forum!

[mro]

Where the caps removed that cover the pilot screws?
If not....may still need a little cleaning and the pilot screws need to be tuned.

You can set the pilots out the basic 1 1/4 or 1 1/2 turns out and synk the carbs. Lot a times engine will seem to run/idle pretty good...but the pilots need to be "tuned" for proper performance.


mro
welcome to XS land, got any pics of your ride?
___

originally post by Ken
The good thing ...

Well said Ken.
There are some pretty good shops out there but we do seem to hear about a few now and then that just can't get the job done.

[TADracer]

Sounds like a tuning problem to me. If carbs are synced well then try tuning from the top down. Its a bit of a pain but it works very well. I had the same problem and this method worked for me. You choose best main jet first then best pilot jet then best needle setting then best idle mixture screw setting, etc.

Here is the link but I cannot get the hang of putting them into a post. http://www.factorypro.com/tech/carbtun.html

[TADracer]

Hey, the link worked!