Hello all, i purchased an 07 Sportster XL1200C last week which had not been driven for approx. 18 months and has 12,000kms on it.
While driving down the highway i noticed that it seems to be surging or a pushing feeling intermittently. At first i thought it was just me , or my hand movements on the throttle or even perhaps the wind, but, when i let the girlfriend ride it she noticed the same thing right away, before i had even mentioned it to her.
When i brought it home it had very little old fuel in it, so i put in a couple of bucks of fresh gas then ran it out, filled it and put in some seafoom, ran it for a few miles and it wasnt better then changed the oil, still not better.
Also now it seems to be lugging between gears, almost like my problems are getting worse instead of better.
The engine RPM's dont seem to change while it is doing this.
Any suggestion?,thanks in advance for any input.

 

Sounds like bad gas or a clogged filter

 

Any mods on it? Changing pipes or A/C without tuning can make surging worse.

 

Just a set of Rineheart's that i am aware of, installed by the dealership when new. I purchased this from, and work with the original owner.

 

Mach, the 2007 1200 is very lean, the throttle action is vague, a PC? will cure it or DK's Xid's at 7%. You'll be amazed at the rheostat like throttle response.

 

The throttle response now is excellent, and it looks , and smells as if it is not on the lean side, but I will investigate that a little further.

 

Inspect the a/c (filter element, opening, breather tubes and backplate)...make sure everything's clear & not gummed-up somewhere.

 

maybe plugs and or plug wires are a bit sketchy?

 

A lot of other owners of 07 models have complained of this surging on the forum. I think the fix is to improve the tuning so it runs richer. either by adding Xied's or getting a better tuner or ECM replacement. I'm sure others who cured it will post their fixes up here for you.

 

Iron is spot on and as I said the the throttle will be improved even if you think its great. For example, climbing a steep hill in 5th gear. Climbing that hill will only require a mere thought of additional throttle rather than a hand full after the addition of a PC III or XIED or. other