Maybe I'm expecting too much from fuel injection on my 1200 low. When I'm at steady throttle,more at lower rpm,it seems to stutter,not a miss. Almost like a carbureted engine,that needed carbs balanced. I read that any adjustments must be made with a computer. When under load it runs fine. It has stock air cleaner, vance hine baloney cut pipes. Is there any way to improve the way it runs?,or balance cylinders? Tom

 

More than likely the culprit is your mufflers. I assume they have the minimal V&H baffles in them. EFI is pretty intolerant of low back pressure in the exhaust at lower rpms. Not only will low end torque be reduced, but the throttle will seem to "hunt" also. This is a pretty common problem when changing exhausts. You need to do one of two things - either increase back pressure with a different baffle/exhaust, and/or spring for a tuner like a Power Commander of a FuelPak and re-map. I'm going through the same thing with my wife's 09 1200. Just put a set of V&H Short Shots on - same problem as yours. I have some "quiet" baffles on the way that should increase the back pressure enough to (hopefully) solve the problem without buying a tuner. BTW, "quiet" is a relative term. V&H Quiet Baffles are only 2-3 db quieter than their regular baffles. Probably should be called "Slightly Less Louds". LOL

Here's a link to a great article that explains it far better than I can: http://www.harley-performance.com/harley-exhaust.html

 

I'm interested in hearing what you think when you have installed the baffles,and tested it.
I also noted that since I have mufflers with little backpressure,that the dealer would have to remap for that change. I hate to spend the bucks for the computerized option.
thanx,Tom

 

Mufflers, baffles and maps have nothing to do with your problem. The 1200 will not run smooth at low (below 2000) rpm. If you are trying to ride at 12 mph (16 rpm in 1st gear) it is going to be rough. It is the nature of the beast.

Bwana

 

Yep below 2k Is for parking lots n parades,,,get into clutch feathering and the friction zone. That should smooth things out for ya.
It's a wet clutch It can handle it.

 

Roadrunner didn't say anything about 2000 RPM, only that the bike stutters at steady throttle, moreso at lower RPM. The problem has EVERYTHING to do with back pressure and all its attendant effects. If the bike ran fine and did not "hunt" with the stock exhaust, but then has problems after a free flowing exhaust is installed, well, in aviation we used to call that a clue. Combining that mod with the right EFI remap will result in a nice power increase, but without that there will be problems. The article I referenced in post #2 explains what's going on pretty well. The stock ECM can compensate for relatively small changes in exhaust flow - hence the SE slip ons can be used with no mapping changes. But if you go with a truly free flowing system, you're going to have to make changes to EFI mapping that exceed the stock ECM's capabilities.

Just had an update from UPS. The "quiet" baffles won't be here until Tuesday. I'll post results as soon as I put them on.

 

I ran it for a couple of weeks with the stock exhaust. It did seem to do the same,but it was less noticable,due to quiet mufflers. I had thought about installing the V/H baffles,but only for a little less noise.
I had thought I may be experiencing what is called a lean misfire. I know they build these engines to run lean. I heard that you have to adjust the mapping to adjust for backpressure change. Has anyone had their engines remapped by the dealer? Tom

 

Tom, I think the baffles will make some difference. The ones you have in now should be straight thru. My understanding is that the quiet baffles have a defelctor in the middle (a "plug"), to force the exhaust gasses around and through the baffle cut outs and fiberglass packing. That by itself will increase back pressure. You're definitely right about the lean condition. Are your spark plugs more white than tan? If so (which is normal for today's factory tuning), then you're pretty lean. The free flow mufflers will make it even leaner.