I've seen a lot of posts about Stage 1 upgrades.

Some people say if you install a higher flow air cleaner and slip-ons, you need a new EFI fuel mapping. Some say the fuel computer will adjust. It's not clear to me what the right answer is.

I have Rush slip-ons and just installed a Screamin Eagle air cleaner (the round one, not the heavy breather) on a 2008 Dyna. Bike sounds fine and runs fine.

How do I tell if it's running too lean or if the computer is compensating OK for the change?

 

one good way is checking spark plugs at each service, google,spark plug signs of wear etc, they will show,due to discolouration what your engine is doing.
or get it plugged into a lap top with diagnostics at ur local garage?

 

checking the color of the spark plugs is one way. When I only changed the ac and exhaust on mine it appeared to run fine until I would crank the throttle and get in the upper rpm range, when I hit about 70mph in 5th and it would start cutting out really bad like it was starving.

 

short of installing an A/F sensor... easiest and cheapest way is to do a 'plug chop' at various throttle positions, pull the plugs and compare them to known examples or descriptions. Procedure is well documented on Google

 

If you do check the plugs make sure you don't let it set around and idle before you pull the plugs. It will give you false readings.

 

These days, with modern clean fuels containing detergents, plug reading will only give you an idea of grossly incorrect fueling. You are unlikely to have that with stage-1 on a Harley with O2 sensors (i.e. >'06).

What you are trying to judge is the difference between, say, an AFR of 14.0:1 and 14.5:1, whereas on a carbed bike that was messed up it might be the difference between 12.0:1 and 16.0:1. That would lead to some much clearer changes in the plugs.

With the changes you have made you will be doing no harm. It might not be operating optimally and it could surge and almost certainly will run a bit hotter though.

If I was you I'd fit a pair of Xieds at least.

 

+1 on the Xieds, which is what I did. Or you can do V&H Fuel Pak or a Fuel Moto unit to keep it simple.

 

It's running lean. It was running too lean when it was bone stock, getting more air in and out is only making it worse. It was never designed to self adjust to where it SHOULD run anyway, so how would it with performance work? It was designed to keep the bike as lean as possible and pass emissions. So it's pretty good at adjusting to way too damn lean. It probably won't blow up on you running like that, but the performance is severely lacking and it runs very hot. It can be a lot worse than some people think and might still seem to run fine. You should see the cylinders and valves on a bike that's been run like that for a long time, or even just stock.

 

the factory ecm will maintaine the afr at 14.7:1 which is set for our emission standards. the spark plugs on newer efi bikes look like new when removed will be a little black on outer ring of plug but ceramic will be white in color so its hard to tell by looking at plugs. if the engine is running very lean it will run hot, possible detonation, and you will notice the exhaust just off the exhaust ports of pipe will be glowing orange you can see it better in low light or dark. the ecm will not add more fuel needed for a higher afr than 14.7:1 and when you increase more air into intake and open up exhaust fuel is needed.

 

Doesn't it ping bad when it runs lean?