Engine missing, spitting, and backfiring

Hey All,
A round for the house!! Having a problem today and its too close to
Biketoberfest to relax. I changed the oil on my wife's bike this
morning and discovered a problem. It is a 98 Springer Softtail. It
hasn't been run in a couple of months and we didn't have this problem
the last time we were out. I started out by warming up the bike prior
to draining the oil. I was also changing the plugs so while the bike
was draining I swapped them out. The bike was running very rough when I
warmed it up and I found it strange that when I removed the plugs, the
front cylinder was pretty hot while the rear was only warm. When I was
done I decided to take it for a ride to make sure all was ok. The bike
is running like crap. Terrible on exceleration, missing and spitting,
and backfiring on coming off the gas. I broke open the service manual
and started to diagnose the problem. I thought it could be a problem
with the wires or the coil so I checked the resistance in each wire and
the primary and secondary points on the coil. They were both within
the range stated in the manual. I am only a gearhead wanna be so I am
struggling with what else to check for. I would appreciate any
suggestions. I doubt I will be able to get an appt. at the shop before
next weekend. Thanks in advance for any help.

 

dud rear plug or lead?

If it's the only thing thats been changed since it ran ok then look there
1st

 

What kind of carburetor? If it's a Mikuni, the idle jets, ports, and
passages are gummed up. You can clean the carburetor without
disassembling it by running 4 or 5 ounces of Berryman B-12 Choke and
Carburetor Cleaner through a full tank off gasoline.

 

It is the stock carb. Thanks. Will give that a try.

 

Sorry if I cover the same ground as previous answers:
1. Bad gas. Put in some Dry Gas or similar product, or drain gas tank
and put in fresh gas.
2. If not the same spark plug brand you had in there originally
(before problems), you may want to try the old plugs.
3. Check that there''s a good connection at the spark plug cap and
wire. Test the ohm resistance in spark plug wire(s).
4. Check oil level in case too high or too low. too high can cause a
problems.
5. Berrymans is the best. A half can in a tnaks of gas twice can help
a lot if carb is gummed up.
6. I t might be the reg/rec or stator, but they are a long shot since
the problem came about so suddenly.

Good luck,

Manjo