I cleaned the air filter also. The dealer told me the plugs were pre-gapped, so I didn't gap them and didn't check the gap. Plugs went in normally, nothing unusual happened when putting them in. I torqued them according to what the maint. book said.

 

It's not normal to smell gas, and it's not burning if you're smelling it. I'd go back over the 20K checklist and recheck the connections on each item. It's not hard to accidently disconnect something like a vacuum line.

 

I beg your pardon, but the thread titlestarted by saying, "spark plugs replaced, now gas mileage down"? We always check the gap.
Scott

 

Spark plug wires usually fail at the terminal ends and often happens with plug changes. Removal
and checking with an ohm meter (wiggle terminals while measuring) is only sure way to tell. New
HD wires usually measure around 6K ohms; up to 12K is OK and not unusual over time. New SE
wires are silicone and just $13 - a good investment. Because removing yours is a pain, loosen
tank, etc, I'd just replace them.

Next item - spark plugs - and I know this will rub some the wrong way but race shops everywhere
will support this opinion. HD factory Champion plugs and their SE Splitfire plugs are junk. Resistance
values are all over the place and finding some that read open is not uncommon. Autolites work fine
for the same price. If you want a long lasting performance plug, Denso iridium is pretty much the
ultimate these days.

My bet is new wires and plugs - your gas mileage is back.

Bob G
'04 Custom Fatboy