So back in late October I completed my stage 4 build. To make a long story short I had the bike dyno tuned and was/still am happy with the results. Fast forward to now, about three weeks ago while out for a ride I noticed my bike ping'ing. Took my bike in today and the tuner said he took some timing out? My question is if it was tuned correctly should this even need to be done and why now after all this time did it start to ping? Also by doing so did I lose any horse power?

 

I would have asked your tuner those questions. I guess you could have some carbon build up in your pistons...How would anybody here know if you lost HP? Didn't you get a print out?

 

I did ask those questions. He didn't know why it happened. And I didn't get a print out cause I didn't have it re-tuned. He just took enough timing out to stop the ping'ing. And I ask about the loss of HP because I don't know if by backing off the timing that affected HP.

Granted the tuner is at my local Harley dealer, so guess ill be looking into another tuner...

 

He actually said it felt as though by backing out the timing it felt as though it gained HP? I can't verify because I didn't ride it cause it was pooring down the rain I opted to just pick it up tomorrow.

 

That is probably the most cost effective thing to do.

 

Pinging is a detonation problem. You might not have enough octane in the fuel you are using and that might be why you needed a change in the timing. As far as loosing a few ponies I would thing it would be negligible and I wouldn't worry about it as long as she is running good.

 

Few things can cause a change from tune. Ambient temperature will have an effect on engine temps. So if tuned on a cooler day one can get away with a more aggressive ignition timing then on a hotter day.
And as brought up the fuel octane, same as on the day tuned or a lower rating?

What tuning device is being used?

 

could you have had bad/wrong gas? Maybe you are at the limit of pump gas and may need to use an octane booster.

 

As stated playing with the timing is not going to have any major or really noticeable impact on the performance of the bike. When I was tuning my bike I tuned on a 85 degree day. After the days started to cool down a little I started to get a slight knock in the front cylinder due to the IAT and VE for that temp. I simply adjusted my timing accordingly in the needed KPA(MAP) for my spark table to resolve the issue. The only real way you would lose noticeable power would be if he screwed with the AFR table. A few slight changes in the spark and VE tables is not going to net or lose much. Maybe .5 if that.

A few things can cause this on tunes. As stated Octane, IAT, and VE. Most of the time its Octane or IAT or a combo of both. This is just the fact of life when tuning a bike with a lot of upgrades for big power. If you tune for ultimate performance then the tolerances of the tune are very fine and the smallest change can cause small issues like this. Personally I like to run my setup slightly fat even if it does not mean max power. I would rather have a cooler reliable tune then something thats hot. I also dont run extremely aggressive timing in my spark tables.

Dont get me wrong I am not saying your tune is "bad" or has issues. I am simply saying that the tolerances of your tune are probably very high for max performance. Not a bad thing at all. I would not worry to much about the tune at this point. If the bike no longer pings I say ride it and enjoy it

I would think that by pulling some time he probably smoothed the power curve a little more than gained anything. Good all around if you ask me

 

Most harley dealers don't know how to tune. IMO the dealer is being lazy by not putting it on thedyno to see whats going on and just playing with the timing blind.

You never said what tuner you had...probably aSERTPRO since the dealer was doing it. You can go to the SERTPRO sticky thread and as some of the expert tuners there and play around with it yourself if the pinging comes back