Members Rides

My 2005

Members Rides

NField Gear

Welcome, Guest. Please login or register.
Did you miss your activation email?
May 31, 2016, 11:11:26 am

Login with username, password and session length


Author Topic: Flat Slide Carburetor Instalation  (Read 1404 times)

Terry Boehm

  • Neophyte
  • *
  • Posts: 2
  • Karma: 0
Flat Slide Carburetor Instalation
« on: December 22, 2012, 08:53:38 am »
This information Iím giving is on my 2003 500cc Royal Enfield that I purchased new. I am running the Ď50s-Style muffler with the baffle removed. I also have a RC-2770 K&N air filter in the original filter compartment that has been modified. You simply cut off the rubber bottom of the filter to fit the original base  and drill a hole in the top to run the mounting rod through. If you choose  this filter make sure you type the dash between the letters and the numbers when looking or it wonít come up.

I have always had problems with the Micarb sticking when giving it full throttle and have tried everything to fix it but nothing helped. Itís in the spare parts box now.

I have now fitted the 30mm PWK Flat Slide Carburetor.  It comes with 140 Main Jet and a 38 Pilot Jet. The description says it has a 19 Pilot Jet but that is not correct. During the 1st test run the engine would pop when I let off the throttle while in gear. Tried to adjust the air screw but it didnít seem to help. I installed the 142 Main Jet and the popping almost completely quit but I had to screw the air screw to get a good idle.
I have some larger Pilot Jets that I may try this spring when the temperatures outside warms up so I can do more testing, or I may have to move the clip on the needle. I was able to use the K&N filter and the original air filter box by using two OEM carburetor connecting tubes used with the traditional cast iron engine. One tube clamps to the air box the other to the Flat Slide Carburetor with a piece of thin wall metal tube 1 ĺ inches long and 1 5/8 outside diameter in between the two connecting tubes. . This makes for a neat & clean look.

Listed below are some of the suppliers and some of the places I found useful information.

Terry Boehm
Danville, Illinois


  • Grand Gearhead
  • *****
  • Posts: 2,168
  • Karma: 0
  • 2003 ES 500... 38,416 miles, I'm done
Re: Flat Slide Carburetor Instalation
« Reply #1 on: December 22, 2012, 11:39:33 am »
Terry, back when I did mine I wound up with a 25 slo jet and a 125 main. It did
run with the bigger mains but there was a rich bog at wfo. My air filter was a
K&N and the silencer was the orig. bazooka drilled thru the baffles and the rear
opened up to 2 1/2" . Have you realized that you can change the main thru
the float bowl drain plug?  3 minute job....  like the look using the tube....
      Once you get by that rich bog, you can grab a handful of throttle in 3rd
gear and run it up to 55 like you wouldn't believe!! Power takes gas so expect
your mileage to drop...
                    - Mike - not missing Illinois a bit!!
« Last Edit: December 22, 2012, 11:45:06 am by baird4444 »
'My dear you are ugly,
 but tomorrow I shall be sober and you will still be ugly'
 - Winston Churchill


  • Grand Gearhead
  • *****
  • Posts: 1,841
  • Karma: 0
  • Karma Ultra: 7
Re: Flat Slide Carburetor Instalation
« Reply #2 on: December 26, 2012, 12:33:00 pm »
I have an AVL engine, K&N pancake, Megaphone exhaust (with silencer) and the PWK 30mm.

122 main
38 pilot
Needle collar in the top notch
19mm float bowl height (I believe they come stock somewhere in the 20's).
Air screw out 1.5 - 2 turns.

Like baird, I was suffering from a rich bog until I took my main jet down to that size.  As with baird's my mileage is lower than stock. Mid 50's usually.

You have JRC Engineering in your link list. They supply NField gear with the PWK and parts.

Good luck, and definitely use that "float-bowl drain hole" main-jet trick baird mentioned to save you a truck-load of time.

Do a search for "PWK flat" and you'll find lots of troubleshooting discussions - Usually me breaking, and everyone else helping fix.
« Last Edit: January 05, 2013, 06:37:45 pm by boggy »
2007 AVL
2006 DRZ400SM

Denny K

  • Neophyte
  • *
  • Posts: 17
  • Karma: 0
Re: Flat Slide Carburetor Instalation
« Reply #3 on: January 05, 2013, 10:47:41 am »
At the end of the summer I installed the flat slide carb available from Enfield.  There was a lot of info from the forum that helped me not only with the decision but ideas on jetting.  I live at nearly 5000 feet so I was interested in adjustments I knew I would have to make.  The install went well and while I had never done anything like this before the bike ran with only a few kicks to get it started.  Then the fun began getting the right jetting.  I tried 3 main jets, working my way down from 140 to 138 and then finally going with 135.  It was easy to do with a small socket after removing the cap at the bottom of the bowl.  I received two pilot jets and stayed with 38, the jet needle is in the mid position.

I installed this carb because I was so unhappy with the OEM carb.  Now my bike starts easily, idles as it should and runs well.  My bike is a 2005 and I wish I had done this years ago.

Mike who does not miss Illinois had some great posts that helped me.