Electrical/Ignition Guru

[XS1100 Newbie]

Well i thought i had my higher rpm miss solved. We adjusted the valves, i adjusted and synched the carbs, we checked and repaired the magnetic pick up wire, checked the advance, and timing. I took a 120 mile ride yesterday, and found the same problem i had before. THIS THING IS DRIVING ME NUCKING FUTS! Question is this: does the alternator run the ignition system, or does it run off the battery? My tach still will make a 2000 rpm drop when this cutout happens, but the rpms have not dropped that far. Has anyone ran their bike with the vacume advance disconnected and pluged? Will it run that way. The problem still seems to be related to the advance. Why do i say this: I can run the rpms up to about 7000 (don't want to push my luck) if i am running down hill, or on the flat, but if i get in a pull where there is no vacume, this problem occures. The bike runs great except for this. The problem does not seem to affect the overall running of the bike at all. I don't worry that the bike will quit running, although sometimes i do wonder. Got any ides?

[Larrym]

Function test

Quick!! Before the sun goes down here at our lattitude!!

Go ahead and disconnect the vacuum advance and plug the port/hose on the carburetor. Then take it for a quick run to see if the same problem reproduces itself.

If the problem persists without the vac advance then the problem/miss is elsewhere: coils? High tension wires/caps?

If the problem goes away then we start following the trail of how come the advance is problematic.

Grab your helmet/gear and GOOO!!!!!!

[79XS11F]

The alternator runs everything and trickle charges the battery. The battery is really only needed to start the bike. 12 volts to run the bike and 2 volts to trickle charge the battery.
My first guess would be fuel starvation when the engine is working. The engine needs more fuel when it's working. The harder it works the more fuel it needs. If the issue was vacuum advance related it should appear even if the engine is not working.
The engine will run without the vac advance but it will run richer and that may fool you into thinking it is the issue when something else is really at fault..
Rob

[Ken Talbot]

When you were working on the pick-up coil wire break, did you stop looking once you found the first break?

Disconnecting the vacuum line from the advance mechanism won't hurt anything. It will minimize how much the mechanism moves, which can keep a broken section pressed together, so it seems to run okay. If you're going to try this diagnostic, be sure to put a cap over the vacuum nipple or you'll introduce a lean situation on cylinder #2.

[XS1100 Newbie]

We did check both wires on the pickup coils. I think i'll give the vac advance disconnect a try to see what happens. I still kind of think that with what happens to the tach when the problem shows, that it may be related to the alternator. Think i'll check it out as well. Does anyone have a higher output alternator setup for the XS1100?

[DiverRay]

Just for fun, try running high speed with the fuel cap loose. If you are starving for fuel, the symptoms may be the same.

[XJOK2PLAY]

Newbie,

If you do end up pulling the alt. apart, one thing to look for will be cracks in the stator winding... along where the epoxy is... mine was cracked up pretty bad in those areas... and was causing some funky tach & light surging action.

Have you noticed any brightening / dimming of all the lights?

A good replacement stator coil was the trick on mine... but I didn't have any engine misfire... course, mine's an XJ, and their vaccuum advance & ignition setups are different than the other 11's.

JAT, HTH's

[tw1980]

Hey Bob,

If you think it might be the coils I have a pair of oems that I know are good if you want to give them a try.Let me know and I'll ship them up your way.
Terry

[Ivan]

So, no miss going down hill at high revs, but miss under load?

Sounds like secondary ignition, if its ignition, or fuel starvation if its fuel.

Check your caps and plugs for carbon tracking. make sure your wires are not touching anything that can allow them to ground. Check your plugs for condition.

Fuel starvation can be anything from a plugged vent, as previously posted, to the wrong main jets. But people usually understand fluid flow better than electricity, so I will leave it to you to check that out.

[XS1100 Newbie]

update!!!

The vac advance disconnect did not make a difference, and the gas cap open did not make a difference. Had to work in the yard, and now a birthday party to go to. I'll check the wires, ends, and the coils when i get home.

[skids]

Try running on prime also to check to see if the automatic valve is not opening full for some reason. I have an xs11E that sometimes acts up at highway speed and if I turn the left petcock to prime, the sputtering immediately disappears.

[tw1980]

Ok Bob I think it's time to go threw the carbs.I know it's a pain but it needs to happen.IMHO Terry

[XS1100 Newbie]

That's not what i wanted to hear Terry! LOL You are probably right, but after the pain i had with the 650, it's not something i am looking forward to.