Quick re-cap: (2000 RKC, injected) checked my plugs the other day - plugged them back in and the bike is now jacked. Went to start the bike and instead of a nice idle it was at about 600 idle and was going (slowly) thump.....thump.....thump.....thump. I thought I did something wrong when I put the plugs back so I took the rear one out and noticed it was wet and smelled of gas. I also thought maybe the idle needed to be reset so I adjusted the cold idle screw to bring it to 1100 but it was still a weird idle so I shut it down.

I posted this scenario and concluded it would be a good idea to replace the spark plug cables. Cheap first step. I just finished doing that and fired up the bike and same thing....running slow and weird.

I have no mechanical knowledge but, could it be the ignition coil rather than the plug wires? Any other suggestions?

(by the way: the day prior to checking the plug wires I detailed the bike - but, I rode the bike that day and all was fine - could it be a day later something I did showed up or is it likely due to the more immediate proximity to checking the plugs.

UPDATE: After some suggestions here I then replaced the spark plugs too and it fired right up. I guess after only changing the wires the plugs were too fouled up to run. Gonna take it for a short spin to make sure it acts right but so far so GREAT! THANKS FOR ALL THE SUGGESTIONS!

 

"checked your plugs" what/why?

did you reinstall same plugs in holes? ( set the gap and remember to use antiseize)

did you crank the motor with the plugs out or the wires off the plugs? - this can blow the ignition coil, sometimes even the sensor



It does sound like maybe you were only running on one cylinder at step one- the wet plug points to that ( next time, just put your hands on the headers, the cooler one is not firing)

idle speed, can you undo what you did? do you remember how many turns you did...

ignition coil- traditional H-D design is that 1 coil is used- BOTH plugs fire at the same time- 1 is used to fire mixture, the other is waste spark.
just so you know- if testing, both plugs fore together.

detailed the bike- any pressure washer used, spraying water into the right side cover and "brains"? or any chance you could have knocked a plug loose somewhere?

mike

 

grab another 2 plugs, Gap them & install. Keep us posted!
hatch.

 

Thanks for the reply and giving me some things to think about.

 

That's another cheap test....will give it a try - I've got a set.

 

my bike started doing the same thing as op yesterday when i first started idled funny, rode a little and seemed fine. took off from parking lot at lunch got to stop light few blocks down bike sounded funny took off and it started to run funny than cleared up. it was after i ate and went to take off that things went south quick, luckily i was just a couple blocks from a harley shop so i limped over there and spent the next 3 hours at that shop my bike kept kicking out a lean code in rear cylinder. The one i bought my bike from came and picked me and the bike up ?'s on warranty but i won't get into that. After 2 more hours of diagnostics they figured out that the fuelpak was bad and now i am having to get a new set up. ditching the fuelpak and getting the SE tuner done. expensive and very frustrating lunch!!

so i guess what i am saying in long form check your ecm or tuner if you got one. i had no symptoms like you. ran fine day before died the next.
good luck

 

My 02 pretty much did the same thing...it was the ECM. Ran on one cylinder. Got all sorts of funky faults that led me astray...replacing parts that did not need replacing.

 

I am going to venture a guess that you were just checking your plugs, just to see if they needed replaced, not because you were having a problem, right????

If you ask me, your problem lies with what you just had your hands on. Could you have accidentally unplugged something? Could one of the spark plug wires not be attached to the coils?

Try looking at everything connected to the ignition electronics, check your fuses, and check your battery connections and grounds, make sure your cables are good and tight. Also, could it be possible you cross threaded one spark plug and it's not seated the whole way in?

 

Just a thought but did you cross the wires when reattaching the plugs?

 

Recheck that the plugs are well seated, and connected at the plug and coil solidly. I was going to suggest that you switch the wires around, and see if the front plug begins to foul. If you have a fuel tuner, try disconnecting that from the system, and run straight to the ECM.