[csbdr]

morning!  I have a 2009 C5 500. Put it away with fuel stabilizer, battery tender etc. Tried getting it out this spring and has a problem it didnt have when put away. Really wants to run rough. Hard to start, even with fresh gas, Once started wants to stall. If I keep working the throttle I can prevent that and get it on the road, but it isnt destined to take me anywhere. It again seems to want to stall. Throttle response becomes "herky-jerky" even when turned gently. At times, it sounds like the ignition shuts down, then lights up again (LOADS of fun on a 2 wheeler....) Other times it acts like a carburated bike with a clogged main (ie: runs at idle, but bogs as soon as you give it some throttle) ALL this joy on one ride out a mile  (and barely back to the garage...) It's kind of hard to describe all the farting, backfiring and general garbage it's doing. Please ask me any specific questions which might help! Sadly it was running GREAT when I put it away...

No ECU codes are showing.

I have been thinking loose connection somewhere? But I dont know where to check for connections in the ignition system. Any helpfor where to start looking?

I was also thinking clogged injectors?  I havent been able to keep it running long enough to run anything through in the gas, like cleaner or Seafoam.

[TWinOKC]

Do the easy stuff first.  How old is the spark plug?

[singhg5]

Could be any number of things so start eliminating them one by one.  From poor fuel supply, moisture in fuel, bad spark plug, spark plug wire loosely sitting on it, loose electrical connection, insufficient air supply, issues with exhaust pipe, weak battery and in my case it was burnt fuse.

As Terry suggested do the simplest things first - take out spark plug and replace if needed.

Several good suggestions for approaching this problem are in this thread -

http://www.enfieldmotorcycles.com/forum/index.php/topic,16451.0/all.html

[csbdr]

Do the easy stuff first.  How old is the spark plug?

Not sure, but likely original.

[csbdr]

i can clarify I have checked the ignition switch and there was a loose connection there which prevented the bike from coming on at all, and fixed that before I experienced the above symptoms. Also, the bike itself doesnt lose power when this is happening as it woulod if there was an intermittant short there.

It has a full, fresh tank of gas, but I will try adding some dry gas. Maybe there is some water in the bottom of the tank.

Battery is fully charged

checked the air filter and it looks clean but I will probably clean and reoil it just to be safe.

Checked the plug connection and it is firm, but I will pull the plugs as well. My understanding though is that you have to run near WOT then shut down to get an accurate plug reading, and then it's subject to opinion. I've never been able to get much out of looking at plug color but I'm not sure I'm any good at it either ;-)

I'm still thinking loose connection. Outside of the ignition switch, which I will check again but I think is not the problem, as the bike doesnt lose electrical when this is happening, are thee any other key connections to look at? and where?

[csbdr]

Can you clean and re-oil the original air filters?  or do they need to be replaced?

[BRADEY]

Enfields have paper filters from factory. Use and throw 

[csbdr]

Enfields have paper filters from factory. Use and throw 

AH, thanks!  I'll change it then. Anyone have a part number in K&N or similar?

[Gypsyjon]

Check the ground wire at the battery. Look under the plastic covering, also check to see if that little wire running in with the neg cable has a good connection.

[1 Thump]

If the filter is clean then no need to change it even if it is original (i.e. came with the bike). However, if the spark plug is original, that needs to be changed pronto. There are numerous threads about the appropriate spark plug for the UCE engine. Did you drain the stale gas ?

[Arizoni]

Sounds like the fuel injector got partially plugged up with varnish or gunk while it was resting.

Try putting some Chevron Techron in the fuel tank and then ride it a few miles.
I'm betting it will perk right up after the injector is cleaned.

[gashousegorilla]

  Mice love to make nests in intakes.... And chew on wires over the winter on stored bikes......  Worth a look.