5.2k rpm wall.

[Banshee's Veil]

Hello,

I have begun the final touches on my xs1100sh. I'm having the following issues that I cant wrap my head around:

1. Whenever I give it WOT she accelerates nicely but then stutters and continues to climb in rpm. The stutter is regardless of gear.

2. Cylinders 1,3 and 4 are rich. Cylinder 2 is either lean or perfect because the plug is clean. I have rebuilt the carbs inside and out and set the floats properly to the last 0.01". Slides functioning fine. Running 115 mains on all jets w/stock pilots.

3. Intermittent Tach. Some days it works some days it doesn't.

Aside from the tach. I'm thinking either coil or vacuum advance issues. Thoughts?

[bikerphil]

If you have pod filters, take a short ride with them off or remove the bottom of the air box. It sounds like you have restricted air flow. For the tach, alternator plug may need cleaning. Bad signal will cause tach malfunction.

[cajun31]

Hello,

I have begun the final touches on my xs1100sh. I'm having the following issues that I cant wrap my head around:

1. Whenever I give it WOT she accelerates nicely but then stutters and continues to climb in rpm. The stutter is regardless of gear.

2. Cylinders 1,3 and 4 are rich. Cylinder 2 is either lean or perfect because the plug is clean. I have rebuilt the carbs inside and out and set the floats properly to the last 0.01". Slides functioning fine. Running 115 mains on all jets w/stock pilots.

3. Intermittent Tach. Some days it works some days it doesn't.

Aside from the tach. I'm thinking either coil or vacuum advance issues. Thoughts?

You never stated what bike you have. It is a good idea to list it in your signature so it will show up in your post. I had a stumble on one of mine and after looking at everything I discovered a split in my hose that went from my vacuum advance to my number two carb. Once I fixed that the problem went away. I have also experienced dirty carbs that resulted in no top end, but you already stated that you have thoroughly cleaned them so I would rule that out. As Phil stated tell us more about your bike and you will end up with better suggestions.

[DiverRay]

He has an HS, as stated in the first post. I'm with Phil, try it without pods if that is what you are running. If you have the stock airbox, and the stock coils, the coils would be my next guess. Probably working OK at lower RPM but will not work at the higher RPM because of less time to "recharge".

[Socer4m]

could be the famous PICKUP COIL wires,,,,pop off the cover, jiggle and pull the wires while running, if it starts misfiring its the wires,,,,,,,,,,easy fix. Also, check your plug wires to make sure they are not grounding out to the engine, start in ta dark area and jiggle with insulated pliers, unless you are brave,,,any sparking its time for a new plug wire...I have had both of these problems over the years and seems parallel to what you are having,,,,Good luck and let us know the progress, Mike in San Diego, Cantafordya

[Banshee's Veil]

If you have pod filters, take a short ride with them off or remove the bottom of the air box. It sounds like you have restricted air flow. For the tach, alternator plug may need cleaning. Bad signal will cause tach malfunction.

Where is the alternator plug?

[Banshee's Veil]

could be the famous PICKUP COIL wires,,,,pop off the cover, jiggle and pull the wires while running, if it starts misfiring its the wires,,,,,,,,,,easy fix. Also, check your plug wires to make sure they are not grounding out to the engine, start in ta dark area and jiggle with insulated pliers, unless you are brave,,,any sparking its time for a new plug wire...I have had both of these problems over the years and seems parallel to what you are having,,,,Good luck and let us know the progress, Mike in San Diego, Cantafordya

I have looked at this and they looked brand new. I jiggled them around with the bike on and nothing.

[bikerphil]

Alternator plug is behind the fuse panel, disconnect the battery before trying to access. If you remove the 3 screws, the flasher relay and the large lower wire on the solenoid, the panel should flip upward and the plug with 3 white wires is back there.

[Socer4m]

I am assuming you checked the pickup wires and they are ok,,,so,,,maybe try spraying wd40, or carb cleaner around the carb manifolds while running, if any missing there is a vac leak at the one you are spraying, also check to see that the gas lines are not pinched and hope you have inline gas filters and they are clean,,,,keep on diagnosing......

[Bonz]

I have looked at this and they looked brand new. I jiggled them around with the bike on and nothing.

Pick-up coil wires will look brand new even if they have broken inside of the sheath. You have to pull on the wire from the ends and see if the sheath stretches at any given point. That is where the break is. That is typically done with the bike not running. Jiggling them while the bike is running potentially won’t reveal an issue, it’s when the advance unit rotates that the wire gets stretched and stressed and will cause the intermittent issue.

[Banshee's Veil]

I replaced vacuum line coming from the pot to carb 2 and I blew out the alternator plug. Tach works and no more rpm wall! Now I can synch and be good to go

[bikerphil]

That's good news.

[Banshee's Veil]

I replaced vacuum line coming from the pot to carb 2 and I blew out the alternator plug. Tach works and no more rpm wall! Now I can synch and be good to go

I spoke too soon. Tach works now but still have the wall.

[bikerphil]

Did you ever ride it with the pods off?

[Bax]

Hi Banshee, I've had a similar symptom a while back. Carbs out of mixture balance after a cleaning was the cause. If I got to 5k on the pilot circuit it would flat line, if I got there on the mains, WOT, it would rip right to 8k. Not sure of your tune methods but your description of the plugs showing significantly different mixtures may want to revisit the pilot screw settings.

---Bax