I have a EFI tuner installed on my Road King and yesterday coming home from a trip with my wife. WE were moving along pretty well at 75 - 80 mph. But when I started up a few of the hills on the way home the bike started loosing power and fell down to 60mph. At one point I had it full throttle but couldn't get it to go any faster. After we leveled off it ran fine??? Any suggestions why I lost power?

 

could be tuner settings or as simple as low octane gas ( which would cause the ECM to retard timing to control pinging/spark knock) or even a dirty/clogged air filter

mike

 

Just got it back from being looked at, found and replaced bad spark plug, also use 93 gas.

 

I've been having a similar issue on my 08 E.G. Classic which unlike your 05 Road King the 08 has throttle by wire, and my issue is that I'll be moving along pretty good on the expressway at 70-75 MPH and if I come on the slightest incline or hill it begins to loose power and the exhaust gets really loud or almost obnoxious when you try to throttle it, it almost wont go and it wont do above 80, then when I get back on level ground again the exhaust quiets back down and it smooths out almost back to normal. I've replaced my in-tank filter and inspected the shell, checked the MAP sensor connector and the ECM connector and put dielectric grease on them, and replaced my two spark plugs, and still have the same issue. Maybe someone who's had a similar issue can suggest what to look at next or how they resolved their issue.
Steve McM.,
Douglasville, Ga.(West Atlanta Area)

 

Yes, that's pretty much describes my problem. Except I fall to 60 mph and can't get it going until I level off.

 

Mine also drops to about 60-65, and since my 08 has a six speed instead of the five speed you have in your 05 I have to down-shift to fifth until I get back on flat ground, then it starts re-gaining it's lost power and I can shift back to sixth gear. I use the stock H.D. 6R12 plugs @ .040, but I haven't checked the plug wires yet, that might be my next try at resolving this matter.

 

we hope to...sometimes they make a mistake or in the case of a large TX chain they were found to be selling regular as premium deliberately

in general, you are better off with name brand fuel at a high volume seller

I have had bad gas at a name brand in a small town on the interstate ( chevron/Blythe/ I-10) I don't stop there no more!
and had less than great gas at a few other places.

just in case a little bottle of octane boost in the saddlebag

stories:
http://www.click2houston.com/news/ga...ested/24653396

http://www.bimmerfest.com/forums/arc.../t-435606.html
and his graph:
http://i816.photobucket.com/albums/z...ampleStudy.png

mike

 

It may have got hot enough to retard the timing. It senses head temp and when it gets hot it starts backing off the timing. My map starts at 284 degrees and goes to 572 degrees. 284 isn't that hot for head temp. Some of the charts I have seen it will back off as much as 12 degrees timing when head temp is very high. The SEPST and TTS I don't think show these tables, but they are in the background. You may try richening the VE tables from 3 to 5 points in the 2500 rpms to 3500 rpms and 10% to 100% throttle position. You can increase the timing in same area a couple of degrees. The throttle position on the timing map is usually in Kpa load. Use 40% to 100% instead of the 10 to 100. Too Slow timing will cause the temp to go higher. Don't know which tuner you have but all the flash tuners I am familiar with use these VE and throttle scales for your model. The PCV will use throttle position for both.

 

Thanks KE5rbd,

I'll have to take a look at the settings.....it is a FuelMoto EFI tuner.