When I first got this 1996 FLHTCU-I Ultra Classic, (EV27 cam, Screaming Eagle air cleaner, 97/98 ECM, Supertrap mufflers), it was running rich, especially when cruising on the interstate, 70/75 mph, so I got a map that closely match my engine, but it was lean, a lot of decel popping. I got a AEM wideband air fuel gauge, I installed AF sensor on the right side, just behind the Y were the front and rear exhaust pipes come together, since then I have worked on getting the A/F ratio as close to 14.7 as I can while cruising, mid 13s when accelerating, and mid 12s when wide open throttle. I am adding 1% fuel to the rear cylinder. When I first start it, it idles at 13.5 AF, when it warms up, it idles at 17.5 AF, when I try to add more fuel to the 0 throttle, 1000 rpms, it idles like crap, the bike shakes, I know that 17.5 is lean but don't think that it will do any damage at idle.
Does anyone have any thoughts or suggestions.

 

If it shakes it suggests the two cylinders are not working equally, as if one is richer than the other. That's the best I can come with at present!

 

Keep in mind Lean is hot. IMHO 14.7 (stoich) is hot. However, not to hot as in causing damage even at a 17. My only concern with a 17 at idle would be the heat idling for any long period of time.
At what point does your idle improve as you start to richen it up? What is your Afr on decel?

 

The A/F gauge does not read when I let off the gas, It does not pop on decal now.

 

Is this a permanent installation, or just for diagnostics?
Any pics, this sounds pretty interesting.

 

Basically, it is permanent, but it could be hooked up as temporary

 

Thanks.
I've installed one in my old car and it provides a lot of good info IMO.


I think I'll put it on the list of things to do for the bike.


Have you got that bung installed in a band clamp?

 

I did get the band clamp, didn't want to get hung up trying to get someone to weld in the bung, wanted to remove the exhaust, drill the hole, and put it right back on.

 

Thanks for all the info.

 

Why isn't it reading on decel?
Glad you have it straightened out though....