I have been adjusting my timing for better mpg and I was told that if you hear pinging and knocking that you have gone too far in the advance direction and should back it off. I think I have heard pinging before when it was hot it sound like quarters hitting a glass and I have no idea what knocking sounds like. If you heard these sounds could you describe them? I do not want to get in to the pre detonation range.

Thank you
Bob

07 road king
Big sucker a/c
Rush slip ons
Thunder max

 

If you hear anything like that re adjust.

 

The only way I know how to describe it is what "breaking glass" sounds like.

 

If you hear anything like detonation downshift, your rpms are too low and you're lugging.

 

Pinging and Knocking are terms for the same symptom. Pinging is probably more accurate to describe the sound on our twin cams - like ball bearings dropped into a glass. My truck, on the other hand, sounds like knocking on the engine, since the firewall,insulation, and heavier engine block remove most of the higher frequency "pinging" sounds.

 

It is hard to describe especially on the Twin Cam because there is so much valve noise. I would describe it as a loud ticking sound. Much the same as a ticking bomb, because that is what is happening to your engine. It is the beginning of a failure situation. Some say once you hear it it is to late, damage is already done. You can check this by seeing if you have aluminum deposits on your spark plugs by the way, that is a sign of major detonation.

 

Sounds like a hammer hitting an anvil or any large peice of metal, kind of like what is actually happening.

 

Like a quarter on glass, or like marbles hitting a peice of steel.................you'll know when you hear it. It normally happens under load when twisting the throttle a bit.............if it happens, retard the timing a bit in that rpm range to prevent it in the future.

Steve

 

I have been working on my bike, a 2008 fatboy. Once I got the thing running again today I have been into the tuning. I have read a lot lately. I don't know how far back this goes but this 2008 and probably the 2007 also and I think one model of 2006 will normally not show pinging or knocking because the ECM can sense this through IONS ??? in the combustion process and retard the timing quicker that you can hear it. With aSERT you can disable this function if you wanted to. There is also a recording program that can be used to see where the retarting is going on.
I guess I'm going to find out a lot about this.

 

When I use to have a stage 1 download and set up. The plugs always had aluminum deposits on them, I ask the dealer if that was ok and of course he said “yes” at that time the bike had about 2000 miles on it so it was well broke in. when I seen the shape the plugs were in I install a pc3 and had the bike dyno tune. The bike ran great but it would ping just a little tiny bite. Now I am using a Thunder max and the bike runs real ruff and the mpg sucks (26.5 gal.) the afr is good 13.5 idle, 13.9 cruising, 12.1 at wot I think it is a timing problem and I would like to advance my timing is two deg at a time a safe amount?