2008 1200c. 11000 miles. For testing purposes stumbles/ surges/ hunts a little 2nd gear 35mph. It’s very minimal but it’s there. All stock except Short shots with baffles and ejk which I’ve played with. Does it with or without air filter on. No vacuum leaks. New/ gapped plugs. Fuses clean. IAC and throttle body clean. No codes. It’s sounds “fluttery” to me when it idles. First Harley so I don’t know normal. This doesn’t feel normal. I can adjust ejk on the fly, it’s in the green zone. 1.5 to about 4.5 makes little to no difference. One user here sent me some timing tables, suggested I may need to get a tuner that adjusts timing. It does feel like it could be timing related, or even valves out of adjustment but they’re hydraulic lifters. How are your basically stock 1200’s running with the ejk? I have until 7 aug to return it if I need to go with a different tuner. Thanks in advance.

 

Pulled plugs they’re both beautiful brown. However pulling the rear plug it broke. I put ngk Iridiums in it when I resurrected it. I put the old stock Harley plug back in it just to test ride it and I think I got rid of half the problem. Are these things picky about plugs? I remember when I got the ridiums they weren’t even close to the stock gap. I had to adjust the gap to get it within spec.

 

I know my touring bike uses ion sensing, so I always use a stock plug. I don’t know if the 1200 uses it. https://www.hdforums.com/forum/touri...s-it-work.html

 

I don’t think Sportsters have it until about 2014. But exceptional info and I appreciate your thought process! I put 7’s in. Since I’ve been researching and I feel I may have stumbled on to a plug issue I’m going to grab some ngk 8’s tomorrow. A little cooler plug. It’s been very hot here. Maybe even some wires.

 

Went with ngk 8’s. It’s almost completely gone. I’m gonna chalk it up to a timing issue with the pipes like Shaneba suggested. I’ll put a meter in the plug wires tomorrow. But I’m pretty much out of ideas. I got the ejk for $175, gotta figure out if I’m gonna return it for a $450 tuner just to solve this issue. But it runs pretty dang good other than this issue, which again is extremely minor now.