[mattsz]

The bosch spark plug that came with the bike are great plugs and don't need to be replaced.

[pmanaz1973]

+1  yeah...rough idle and poor starts.  It went away when I switched to NGK.

[High On Octane]

This problem is almost certainly flooding due to a bad fuel injector or a ground fault on the fuel injector wire.  This explains the spark plug fouling as well as the dieseling you've described; not to mention the trouble light.  The bosch spark plug that came with the bike are great plugs and don't need to be replaced.  Remove the plug and O2 sensor and burn off the unused fuel and carbon residue with a torch.  Good Luck.

Most, not all, would argue that the NGK is a far superior plug compared to the Bosch.  And honestly, I wouldn't even put Bosch plugs in my ex-wife's car.   

[Craig McClure]

Most, not all, would argue that the NGK is a far superior plug compared to the Bosch.  And honestly, I wouldn't even put Bosch plugs in my ex-wife's car.   

+1....I had problems with the stock Bosch plugs.  Over the years I also had problems with crankcase breathers fouling my air filter & causing rich running. If you have a greasy mess in your air box this is happening. The UCE Enfields are prone to puke some oil out the breather. I plugged the breather nipple on my air box re-routed my breather hose out the rear of the bike, as I have done on all my bikes over the last 20 some years (since the DOT made this stupid regulation) Start there, I'd bet your problem goes away.

[Kevin Mahoney]

Quick comments
1. If your bike comes from the Indian market it is most likely that it does NOT have a sidestand safety switch. One look will tell you but in the US the government is in a mission to protect us from ourselves and judging from what I see it isn't working.

2. Can't comment about the NGK plug in a twin spark
3. They only puke oil into the airbox if they are overfull.
4. Lower amperage battery will not give you the trouble you are talking about assuming it is not a flashlight battery

[Craig McClure]

Quick comments
3. They only puke oil into the airbox if they are overfull.

EXACTLY, I have a had a hell of a time getting the right amount of oil in, using the sight glass, which is why I always whine about not having a dipstick to check the correct level.
THIS HAS BEEN MY MAIN UCE COMPLAINT. My problem went away when I rerouted my breather hose. Now any excess oil just goes out the rear. Don't tell the DOT.

[Kevin Mahoney]

Typically by using the factory recommended procedure for checking oil levels we don't see many issues from customers. Run engine for a couple of minutes, put it on center stand on LEVEL ground and check sight glass. Halfway between the high and low mark is perfect. It is critical to run it for a couple of minutes and have it on level ground. You cannot check it while running like some engines and you cannot check it properly before it has been run and then shut off.
There is no downside to running a breather overboard I guess except for adding to pollution.