Okay, so I know the question about putting slip-ons without a tuner has been beat to death and the general concensus seems to be "it depends".

What I need to know is...what is okay and what is not? My list so far is:

Okay:

Some "gurgling" from reversion
A slight backfire every once in a while

Not Okay:

Moderate to severe backfiring
Any pinging
Fouled, pitted, damaged spark plugs
Ridiculous heat
General, all-around running like crap

I'm going to go ahead and buy my slip-ons. If they are not okay I'll put the stocks back on and wait until I can get the full stage 1 with a fuel manager of some sort.

P.S. I'm putting Thunderheader slip-ons on a bone stock '09 FLHR if anyone wants to comment specifically on them.

 

Tune the bike before you burn it up. It's gonna run too lean. Did you put an air kit on it?

 

They sound great! BUt they are a little bit too loud. I can't stand to ride behind my buddy that has them on his roadglide