I currently have a 16 FLHTK, had an 11 Road King before that. One thing I have noticed is both bikes run great, no pinging or knocking in the spring. It seams that every year after our trip to the Smoky Mtns, usually mid summer, I fight what sounds like pinging for the rest of the season not terrible but definitely more than in the spring . I always run 93 octane when in my area. Could it be the hotter air temperature later in the summer that causes this.
Just wondering if anyone else has had anything similar. I have a Power Vision and tried retarding the spark last year but that didn't seem to help.

 

Have you checked/changed the spark plugs? That would be the first thing I would look at if you think it's a spark knock. Read the plugs and see if that's actually the problem. There are safeguards in the programming that should automatically pull timing if spark knock is detected. If you bought the PV from Fuel Moto, I'd contact them and discuss changing the tune a little. If not, I'd contact Dynojet and have the same conversation. Either way, you definitely need to get it fixed.

 

Yeah, I changed the plugs last year and that didn't make any difference. I was talking to someone today and they said to check the plug wire on the front cylinder where it rubs on the tank. Looked at it when I got home and you can see and feel a dent in the wire covering, it's not through but I think I will change that.
Like I said it's not bad but it's just weird that it doesn't do it till about mid way through the summer, that what has me thinking it's when the temps are hotter. If it starts again this year I will contact Fuel Moto since thats where I got my Power Vision.

 

Could be warmer temps combined with summer blend of gas?

 

 

Is there a certain situation that it consistently does it? Under a load, going uphill, rpm range, etc? If you downshift in that situation, does it still do it?

 

Yes, the plugs were replaced with the 6R12 from the Harley shop. Usually notice it under hard exceleration or up hill with a load around 2700 rpm, but like I said this time of year it is fine, I can get heavy on the throttle and it doesn't make a sound, but last few years later in the summer it seems to creep up on me. I thought last year it was from getting some bad gas but it kept doing it even after running several tanks through it after getting back from vacation.

 

Have you tried any quality octane booster when it is acting up? I would find some Torco Unleaded Race Fuel Concentrate to try.

 

I'm going to make a strange recommendation, that I have no proof will work. I used to do a lot of custom tuning on my Mustang, so it's completely apples and oranges, but free and worth a shot. The ECU on a Mustang makes small corrections for VE and stores those fuel and spark corrections in what is called the Keep Alive Memory, or KAM. The only way to clear that data, was to pull the negative cable on the battery and press the brake pedal, or something else to completely drain any residual energy in the system. Most would leave it disconnected for 10-15 minutes just to be certain.

I don't know if there is a similar function built into the HD ECU or not, but it may be worth a shot. My theory being that the ECU has stored correction values that relate to the cooler temps and is advancing the timing too much under those load values.

 

Makes sense to me.