[BRADEY]

Wondering if there is a tutorial or DIY video on
how to disassemble the fuel injector and Throttle body
for cleaning and overhaul. I could not find much on this
subject in the manual either ! Please ignore if this subject
has already been discussed. However please point me to
the correct link. Thanks

[GSS]

Some info to get you started.....there is a boatload over at the popular Indian site as well.
http://www.enfieldmotorcycles.com/forum/index.php?topic=14467.0

http://www.team-bhp.com/forum/motorbikes/

[Vince]

     This is a non-issue unless you left it in a flooded ditch over the winter. Just run good quality gas and ride the bike regularly. I have never see an injector or throttle body on any bike that needed "maintenance". I have repaired/replaced a few that someone has "maintained". If you have some kind of problem it is probably electrical, not mechanical.

[BRADEY]

GSS, Vince thanks for your response.
The reason I am interested to do the maintenance
is because, my bike hesitates when I roll on the throttle
after a quick roll off, usually in traffic. Which makes me
believe that perhaps the spray of the injector is not a fine mist
as it should be, and may have become coarse. This is similar to
the AF mixture, rich...............sorry but I am not very good at injectors !!

[Vince]

      Even with the wonders of fuel injection, you are dealing with a long stroke single. I can make any similar bike stall and stumble if I yank the twist grip. They rev too slowly for the amount of vacuum they generate, thus it will always run lean and stumble with a quick yank of the throttle. The cure is to roll on the throttle a little slower at low RPM.
     There is one adjustment you can make to the system, but unless you are having other issues, I would try a slight change in throttle actuation. Try it and let me know. We can adjust for a richer mixture if this doesn't work, but that can lead to a plug fouling situation.

[GSS]

Techron fuel injector cleaner, followed by Seafoam in a tankful a of gas would be worth a try before you take things apart....I am assuming you already have the NGK spark plug? Is the idle set too low?

[Arizoni]

I would go the Techron route.  It did wonders for my fuel injected BMW.

The actual fuel injector is not made to be disassembled.
If it is taken apart the super fine wiring in the coil that operates it would undoubtedly be damaged and the jets are too small for any mechanical way of cleaning them.

The Techron on the other hand will chemically dissolve any varnish or crud that has built up in the injector.

[BRADEY]

Even if the roll back on the throttle is very gradual and deliberate
the bike still hesitates a tad, which my carbureted bikes never do.
However It still gives me a very good mileage of 81 miles per US gallons
on highway, so I am not sure if the problem is with the injector or elsewhere !

[High On Octane]

If you're getting 81mpg you have got to be running seriously lean.  You should pull your spark plug and see if the electrode and ground strap are white in color.

Scottie

[gashousegorilla]

If you're getting 81mpg you have got to be running seriously lean.  You should pull your spark plug and see if the electrode and ground strap are white in color.

Scottie

   +1

  Although on my bike, we found on the Dyno . That the bike would go extremely rich when cracking open the throttle with the stock ECU.

[BRADEY]

No the bike is not running lean.
The flame side of the plug (Bosch WR8DP)
is coffee brown and the opposite side a little off white.
There is very little sooting or carbon deposits, which makes
me believe the bike is not running lean. However it could well be
that momentarily the mixture becomes rich, which may make the
bike hesitate a bit, both in slow RPMs as well as mid range sometimes.
NGK BPR6ES is not available in my region in India........
Maybe somebody could help me source it, and I may pay by Western Union
or something like that ??

[JVS]

No the bike is not running lean.
The flame side of the plug (Bosch WR8DP)
is coffee brown and the opposite side a little off white.
There is very little sooting or carbon deposits, which makes
me believe the bike is not running lean.

The bike does sound it is running lean. No carbon deposits/very little sooting is an indication of a lean mixture, not rich. Please purchase a NGK BPR6ES over E-Bay or the like. Any other plug besides the stock one in India will be an improvment. Try purchasing a 'Champion' branded plug for UCE engines at a local mechanic. They might be able to source it for you. Spark plug gap should be 0.7mm-0.8mm.

Some plug readings for reference -

http://www.gnttype.org/techarea/engine/plugs.html
http://www.motocrossgear.com/wp/wp-content/uploads/2011/12/plugdiag.jpg
http://www.angelfire.com/fl4/pontiacdude428/Readplugs.html
http://www.dansmc.com/spark_plugs/spark_plugs_catalog.html

[High On Octane]

Stills sounds a little on the lean side if the sides are whiteish.  Have you tested or made any adjustments to your TPS?  Maybe that could be causing the fluctuations between rich and lean.

Scottie

[Vince]

     On the top left rear of the injector body there is a post. In the post is a recessed brass screw. Mark its position. Use a flat head screw driver and turn the screw 1/8 turn clockwise. This will change the starting point for the programming and will slightly richen up the mixture. This should help. If it doesn't you can go back to the position you marked.

[Arizoni]

BRADEY
If you can't find the NGK BPR6ES, look for a Autolite 63, NDE W16EXR, Champion RN9Y, MEIYA F6RTC,  or a DENSO W20EPR-U.