I will occasionally get some pinging from my motor. It occurs at the beginning of acceleration while in cruise mode.........say, if I am passing a vehicle in front of me. It doesn't happen constantly. Specifically, it will happen if if I've been cruising at a constant speed for any length of time, and when I roll on the throttle. Never happens from a dead stop to acceleration. No decel popping at all. My motor is a basically stock TC103 save for SE A/C, SE 65115-98B Slip-On mufflers, and SE TC103 Stage 1 Race ECM flash P/N: 34303-06. Oil temp is running between 225 and 231. I use premium gasoline, usally 91, but try to get 93 when I can. This started with the onset of hot weather. Noticed it several times while coming home from Kansas last week, and during rides yesterday and this morning. Any ideas?
More questions. I understand detonation to be preignition of fuel prior to the pistons completing their full compression stroke. Are the terms "detonation" and "pinging" used interchangably? Is one different from the other? Or are they they same thing? Thanks.
Henry,
Technically, there are two different conditions that people call "pinging".
Preignition is a condition whereby the fuel/air mixture is ignited early, usually by a local hot spot in the combustion chamber such as carbon deposits or a sharp edge.
Detonation is a different condition whereby a portion of the fuel/air mixture "explodes" after the plug has started combustion, rather than burning smoothly. Of the two conditions, detonation is much more common and is the issue most of us see on our Harley's.
BTW - I didn't experience much "pinging" last year with my setup (stock 103, SE A/C, Slip-Ons, PCIII), but I did this spring with the exact same setup. Two causes come to mind: Refiner's were slow to get summer blends into circulation this year, especially on slower moving products like premium, and we had some early high temps in the 90's, and H-D injectors are not very resistant to fouling. I ran a couple tanks of gas through with extra injector cleaner (4 oz. per 5 gallons), and improved my pinging during roll-ons by about 60%. I've got two new injectors ordered, since cleaning these things on the bike is rarely 100% effective. I'm thinking about sending the originals to this place for professional evaluation and cleaning: Marren Fuel Injection
http://www.injector.com/ Jerry