Sudden loss of power and heavy vibration

[Phare Est]

I was driving my XS11 a couple of days ago when all of sudden, the bike lost a lot of power and started vibrating abnormally. It would not go faster than 80 km per hour (50 mph) at full throttle. I drained the fuel out to remove the petcocks : nothing was blocking the petcock screens. I removed the exhaust to check if anything was clogging it, but everything seemed clear. I think the bike did need a carb synch, but could this explain the sudden loss of power and the heavy vibration? Could it be a fuel starvation issue?

[Bonz]

Were all 4 exhaust tubes hot coming off the engine? Sounds like you dropped a cylinder(s). Spark plugs, plug wires, coils potentially could be culprits. Does it start/run normally now that it has cooled off?

[kboehringer]

Pick-Up Wires... 99% chance that's the issue!

Leave the carbs alone! Check your pick-up wires.
Experienced this myself.... They are under the left side cover.

These are 100% silicone coated wires (4) this is the ONLY major design problem with the XS1100. There are easy to test.... Multiple threads on the topic.

Ask Marty! He had to help me splice 'em back together on my DEAD DUCK on the way back from a bike show in South Carolina. Lost two cylinders and the damn thing wouldn't do more than 50mph with full throttle JUST LIKE YOURS! Running at 50% and dragging to dead cylinders will do that to ya!

If not those..... You probably lost a coil... Original 40 Year old Coils?

[Phare Est]

Leave the carbs alone! Check your pick-up wires.
Experienced this myself.... They are under the left side cover.

These are 100% silicone coated wires (4) this is the ONLY major design problem with the XS1100. There are easy to test.... Multiple threads on the topic.

Ask Marty! He had to help me splice 'em back together on my DEAD DUCK on the way back from a bike show in South Carolina. Lost two cylinders and the damn thing wouldn't do more than 50mph with full throttle JUST LIKE YOURS! Running at 50% and dragging to dead cylinders will do that to ya!

If not those..... You probably lost a coil... Original 40 Year old Coils?

The air coming out of the exhaust is indeed cooler on cylinders 2 and 3 than it is on cylinders 1 and 4... I put new spark plugs in, but there was no improvement. I will be checking those pick-up wires.

[speedlimit85]

http://www.xs11.com/forum/showthread...=pick-up+wires


http://www.xs11.com/xs11-info/tech-t...pictorial.html

[skids]

You can get a cheap spark indicator light. Pretty easy to use.

[Phare Est]

No luck yet

http://www.xs11.com/forum/showthread...=pick-up+wires


http://www.xs11.com/xs11-info/tech-t...pictorial.html

I pulled on all four pick-up wires while the bike was running to see if the was a break in one of them, but nothing happened. I replaced the two longest pick-up wires (red and light blue) by soldering them and sealing them with heat shrink tubing:
https://lh3.googleusercontent.com/ji...c=w955-h716-no.

Cylinders 2 and 3 are still not working. Should I go ahead and replace the other two (white and light blue) wires? Could the ignition coil(s) be the problem?

[kboehringer]

Phare Est,

If they are already broken they should pull like rubber bands. And, if they are already broken, you're not really going to see them improve by puling on them while it is running? Squishing them together, MAYBE.

Also, I've replaced these wires before several times BUT you can't use just any old wire. For troubleshooting, SURE, for a lasting repair definitely not. There are some guys on evil-bay selling multi-color packs of 100% silicone coated flexible wire for just a few bucks. You've gotta use that right stuff as normal wire won't put up with the back-n-forth of the timing plate. This is what kills the OEM wires over time.

Some will also suggest strongly against solder. Personally, if done well and correctly FAR AWAY from the continuous bending area it should work just fine (mine do!).

Kurt

[xs11lover]

“you can't use just any old wire.” Oops. You may want to remember that for the day Mike Smedly finally brings my prize Xs11 special into your shop. Lol

[Bonz]

Swap the known good coil/wires from 1,4 with the 2,3 coil/wires. Tell us if 1 and 4 are now not firing.

[Phare Est]

Swap the known good coil/wires from 1,4 with the 2,3 coil/wires. Tell us if 1 and 4 are now not firing.

I will certainly swap the coils later on today. I measured the resistance on both of them with an ohmmeter and got a reading of 3.0 ohms. Is this correct?

[red bandit]

3 ohms is correct for the primaries. What does the secondary's measure?

[DiverRay]

The easy check is to move the plug wires so 1&4 now go to 2&3, and then swap the connections at the coils. Then firs the bike and see if 2&3 are now hot. If not, you have a bad coil. If they are now hot, you have pickup coil/wire problems.

[Bonz]

^^^ What he said ^^^

It’s what I was thinking, just didn’t come out that way.

[CaptonZap]

I pulled on all four pick-up wires while the bike was running to see if the was a break in one of them, but nothing happened. I replaced the two longest pick-up wires (red and light blue) by soldering them and sealing them with heat shrink tubing:
https://lh3.googleusercontent.com/ji...c=w955-h716-no.

Cylinders 2 and 3 are still not working. Should I go ahead and replace the other two (white and light blue) wires? Could the ignition coil(s) be the problem?

It sounds like the bike was running on all four when you checked it.
One other thing to remember is that coils sometimes get inoperative after they get warm. The coils expand, and the cracked wire opens up, and they quit. They cool down, contract, and work again. So ride the bike with an ohm meter and the tools necessary to get to the primary and secondary coil circuits in your pocket, and go ride around the block till you get tired of it, or the miss starts.
Then measure the continuity through both internal coils of both coils.