Unofficial Royal Enfield Community Forum

Royal Enfield Motorcycles => Bullet Iron Barrel => Topic started by: Guaire on April 19, 2013, 05:53:44 pm

Title: Fresh plug
Post by: Guaire on April 19, 2013, 05:53:44 pm
I cleaned the K&N air filter and re - oiled it. I installed a brand new plug and rode about 25 miles. Looks rich. The old plug looked rich. When I get time I'll pull the Mikuni and see what I've got running. Any suggestions, cautions....? Here's some plug pix.
Title: Re: Fresh plug
Post by: ace.cafe on April 19, 2013, 06:37:20 pm
If the plug was subjected to various throttle settings during the riding, and shut off at idle, there is no way to adequately gauge which jet(s) might be rich.
It could be as simple as too rich of a setting of the idle air bleed screw. Or it could be rich all over.
Plug chops done at certain throttle positions will more likely yield answers to which jets need attention.

Most street riding is done between 1/4 to 3/4 throttle, which means the needle jet and needle position will be the most influential mixture items to look at.
Title: Re: Fresh plug
Post by: Guaire on April 19, 2013, 06:40:35 pm
Thanks, Ace. I'll start by doing an air screw adjustment.
Title: Re: Fresh plug
Post by: D the D on April 19, 2013, 07:31:51 pm
Guaire,
If you do check the jets they can be removed by just removing the float bowl with a short screwdriver instead of removing the whole carb.  Be sure to turn off the petcock and put something below the carb to catch any spilled gas.  You still have to remove the carb to mess with the needle height, needle jet, or measure the float height correctly though.  Been around this a few times lately.
Title: Re: Fresh plug
Post by: 1 Thump on April 19, 2013, 08:50:58 pm
On the Mikuni TM32 you need to take the carb off and remove the slide to change the needle setting. Its probably the same process for which ever Mikuni you have. After the pilot jet the needle is the second thing you will want to tune followed by the needle jet...and then the main jet.
Title: Re: Fresh plug
Post by: High On Octane on April 19, 2013, 09:58:43 pm
I'm sorry...  What the hell is "plug chops" and what is it's function?

Scottie
Title: Re: Fresh plug
Post by: ace.cafe on April 19, 2013, 10:28:02 pm
I'm sorry...  What the hell is "plug chops" and what is it's function?

Scottie

Plug chops are a way to isolate each major throttle position's mixture setting, by isolating the jets which control the mixture in those throttle positions. With these types of carburetors, you can be lean in one throttle position, and be rich in another. This process allows you to tune each throttle range and the corresponding jets.

The process is like this.
Put a piece of tape or other indicator pointer on your throttle housing, like an arrow pointer.
Put a piece of tape wrapped around your throttle grip. Then use a magic marker on the tape to mark the 1/4, 1/2, 3/4, and Full throttle position, so that they correspond with the pointer when you are at these throttle positions.

Use a new plug.

Then, take the bike out and ride at one of these throttle positions for a few minutes so that the plug can get enough time to get its color. Hold it at that throttle position the whole time without changing it, so that it isolates that throttle position only. When you get to a safe place to pull over to check the plug, cut the engine and pull in the clutch, don't change the throttle position until the engine stops,  and coast to a stop on the side of the road and check your plug for color.
If the color is a medium tan, or something around that, it's pretty good for that throttle position, and you can try the next throttle position, etc.

Throttle positions and their corresponding jets are:
Idle = Pilot jet and bleed screw
1/8 = Throttle slide cutaway
1/4 = Needle jet mostly
1/2 = Needle jet and jet needle combination(they actually overlap in function from 1/4-3/4)
3/4 = Jet needle mostly
Full = Main jet

Doing this will give good even throttle results with proper mixture settings all thru the whole throttle range, and should eliminate any hiccups, bogs, or flat spots in the entire throttle range, and prevent lean conditions from causing engine damage, and keep your fuel economy at its best.
Title: Re: Fresh plug
Post by: High On Octane on April 20, 2013, 01:34:58 am
Right on!  I was not aware of that trick.  Once I'm up and running I'll make sure to do that.  Thanks for the info!

Scottie
Title: Re: Fresh plug
Post by: Ice on April 20, 2013, 03:12:41 am
Guaire, exactly what plug is that ?

Title: Re: Fresh plug
Post by: Guaire on April 20, 2013, 01:39:05 pm
Ice, it's a B8ES. Not an 'R'. The cap is the resistor, 5K.
Title: Re: Fresh plug
Post by: jdrouin on April 20, 2013, 05:19:44 pm
Another little thing that can sneak up on you is the rubber grommet at the base of the enrichener plunger. It can pop off the lip it's attached to and prevent the enrichener from going all the way off, causing an excessively rich running condition. I was fouling plugs like crazy last year until a forum member suggested it.

Turns out that was my problem, and it was easy to fix with some silicone gasket sealer that can bond rubber and metal. Don't remember what I bought but I can check my garage when I get home, if you like.

The grommet in question is circled in yellow on the attached picture.
Title: Re: Fresh plug
Post by: Guaire on April 21, 2013, 12:22:50 am
Thanks, JD, I'll take a look at that. Although my carb is a Mikuni, it shares a similar part.
  nfield is offering the K&N air filter for $10. I'll get a new one. Next, I'll dial in the low speed on the lean side and see where that gets us. After that I'll open the Mikuni and catalog the whole setup.
  I cleaned and re - oiled the K&N, but for ten bucks I'll have a new one. K&Ns are known flow flowing lots of air. I'll track this down, one thing at a time.
Title: Re: Fresh plug
Post by: Guaire on April 25, 2013, 01:52:17 pm
I ordered a new K&N to make sure I'm getting the best air flow. On this Mikuni there are two adjusters. I assume one is the low speed air adjuster, and the other is the 'throttle stop', similar to an Amal. Which is which? On the air screw is screwing it in rich and screwing it out adding air [lean]?
  When I get the new filter I'll remove the carb and see what I have for jets, needle and slide settings and take it from there.
Cheers,
and thanks,
Bill
Title: Re: Fresh plug
Post by: Blltrdr on April 25, 2013, 03:05:44 pm
I don't understand why you would order a new K&N to replace one you already had. Unless it was damaged those filters will last the life of the bike with cleaning and oiling every so often.

Check this out: http://www.mikuni.com/pdf/vmmanual.pdf
Title: Re: Fresh plug
Post by: Guaire on April 25, 2013, 03:16:27 pm
For $10 it's worth it to know for sure, I'm getting the best airflow. I already used the K&N kit, but who knows.
Title: Re: Fresh plug
Post by: High On Octane on April 25, 2013, 03:18:30 pm
I don't understand why you would order a new K&N to replace one you already had. Unless it was damaged those filters will last the life of the bike with cleaning and oiling every so often.


For $10 it's worth it to know for sure, I'm getting the best airflow. I already used the K&N kit, but who knows.


Actually, had you sent K&N an email explaining what was up, they would have sent you a brand new filter for free.  They DO have a million mile warranty and they DO honor it.

Scottie
Title: Re: Fresh plug
Post by: Guaire on April 25, 2013, 04:46:48 pm
Thanks, I got the a look at the Mikuni pdf. I know the air screw now. After I open the carb I'll know how it's set up.
Title: Re: Fresh plug
Post by: Guaire on April 26, 2013, 05:55:04 pm
Yesterday I pulled the carb. It's a round slide 34mm Mikuni, from Sudco. It's a Royal Enfield setup from Sudco. I just talked to a Sudco tech in CA. The only difference between what I have and their standard RE setup in my main jet. Their's is a 210. Mine is a 195. All other parts are identical to Sudco's standard setup.
  I'll be ordering a rebuild kit. When I opened the float there was something that looked like parmesan cheese in there. Any clogs in the internal air passages could make it run rich. I'll order the 210 main, just in case it takes one to get it right.
  Here's a post from ACE. It's about the Mikuni flat slide. The numbers are different, but I have a round slide.
  It's better that I rebuild this thing than just fiddle with the air screw. Every one here is so willing to help. Better to get done right from the inside, then ask questions.
Here's some of the gunk.
Here's ACEs post....
I would say that a 30mm or 32mm Mikuni would be fine. In fact, a 32mm Mikuni Flat Slide carb is what we normally recommend for all Bullets, but we are taking into account that they will stick with the one carb as they upgrade their power levels. IF you have no power upgrade plans which include increased breathing of the cylinder head, then a 30mm would do fine.

You'll need to re-jet any of these carbs, because they come jetted for other bikes which are not like ours.

30 pilot, p6 needle jet, 190 main
would probably be a good jetting start for a stock bike and a Mikuni TM32-1.

Pilot jets are 22/210 type
Needle jets are 389 type
Main jets are 4/042 type.

Title: Re: Fresh plug
Post by: D the D on April 27, 2013, 04:56:31 am
It has the large Hex jets, right?
At least it's not full of white blooms and pitted inside, so a good cleaning should fix her up.
Title: Re: Fresh plug
Post by: ace.cafe on April 27, 2013, 12:31:10 pm
The 34 with a stock bike might like a slightly richer jet like a 200 or 210.
It might not be a bad idea to start with the 210 and work down if it needs leaner.
The 34 has a slightly reduced metering signal at the jet, due to the carb being slightly larger than the port. This means it doesn't pull the fuel up from the jet as hard, and may need slightly richer jetting because of that.
Title: Re: Fresh plug
Post by: Guaire on April 27, 2013, 06:25:38 pm
Ace - Thank you very much for your experienced opinion. I didn't know how this was going to set up. I didn't know the differences between the Sudco/Mikuni 34 for Royal Enfield and the 32mm setups. Now I know what to order from Sudco. Do you sell these Mikuni parts?
I'll be getting the float bowl gasket, float chamber plug gasket, needle and seat, 2 washers. The cable is fine.
  D the D - "It has the large Hex jets, right?
At least it's not full of white blooms and pitted inside, so a good cleaning should fix her up." That's encouraging. I've seen worse inside carbs. Here's a pic of the 195 main jet.
Cheers,
Bill

Title: Re: Fresh plug
Post by: D the D on April 28, 2013, 03:16:48 am
Yep, that's a 4/042 commonly called the "Large Hex" Main Jet.  They're common as dirt and easy to get.
Title: Re: Fresh plug
Post by: High On Octane on April 29, 2013, 04:22:45 pm
Guaire - That cottage cheese crap that was sitting in the bottom of your bowl is what ethanol blended fuel turns into after it has sat for a long time.  Get yourself a .009 electric guitar string and use it to clean your fuel and air passages as they are probably clogged up with that cottage cheese crap. 

Scottie
Title: Re: Fresh plug
Post by: ace.cafe on April 29, 2013, 04:30:57 pm
Ace - Thank you very much for your experienced opinion. I didn't know how this was going to set up. I didn't know the differences between the Sudco/Mikuni 34 for Royal Enfield and the 32mm setups. Now I know what to order from Sudco. Do you sell these Mikuni parts?
I'll be getting the float bowl gasket, float chamber plug gasket, needle and seat, 2 washers. The cable is fine.
  D the D - "It has the large Hex jets, right?
At least it's not full of white blooms and pitted inside, so a good cleaning should fix her up." That's encouraging. I've seen worse inside carbs. Here's a pic of the 195 main jet.
Cheers,
Bill

The jets can typically be bought at any local HondaYamaKawaZuki shop.
Title: Re: Fresh plug
Post by: Guaire on April 29, 2013, 05:07:57 pm
I just got off the phone with Sudco. My parts are on the way.... end of week maybe. Next time I'll check at my local dealer, now that I'm more familiar with the carb and parts. I can just identify things now.
  We sound like a dietary website! Cheeses of various types. I remove all parts from the body and drop the lot in McKay's cleaner. I couldn't remove the pilot jet. I have machinist's screwdrivers, but I couldn't get enough torque to remove it.
  Overall, my worry is getting enough air into the fuel mix. 34mm was the largest VM offered by Sudco. They also had a 32mm and a 30mm. Hopefully, the air passages in the body will lose the cheese and be open, giving the mixture enough air, so I'm not running as rich.
  It's main jet was a 195. I ordered a 210 (stock on this kit) and a 200.
Title: Re: Fresh plug
Post by: High On Octane on April 30, 2013, 05:39:54 pm
If you get yourself a guitar string it will help immensely cleaning out all the fuel and air passages.  And strings are cheap, you can buy individual ones from music stores for like a buck or 2 or get an entire pack for $5-$7.  Just use wire cutters to trim them down to a useable length and bend a handle in 1 end to hold onto it.  I used to have to do this to my motocross bikes on a regular basis and they work great.

Scottie
Title: Re: Fresh plug
Post by: Guaire on May 05, 2013, 03:30:10 pm
Scottie J - Instead of a guitar string, I went chemical. McKay's can't be made any more. I used a Yamaha product. It takes a water dilution at 2 to 1. I tested a NAPA dip can with the drain bolt of the bowl. Ho hum results. I'll use it for hardware clean ups. I let the parts sit in the Yamaha cleaner for several hours and it was okay.
  Sudco (and Ace) let me know the 'stock' setup on my VM34. the 35 pilot jet went to a 40. The 190 main, went to a 210. When putting the fuel line together, I added an inline filter with fresh cables. I dis-assembled the petcock bowl. Cleaned the filter and bowl. The new K&N went on.
  Attempting to start, I couldn't get a start with the choke on. I pulled the plug. It was wet. I blew it with air. Blew air across the plug hole. Checked for spark - good. Kept the choke off and started. Enfield on!
  From there I went out for a warm up run. I had the air screw at 2 1/2 turns out and the throttle stop touching the slide. The Bullet pulled great. No flat spots. After a few miles I looped around to my local dealership, Coleman's in Falls Church. In their parking lot, I set the air screw and throttle stop. I kept the air closer to lean than rich.

  Back to the driveway at home. I did an oil change. I bought the 5 pack from nfield for oil changes. My oil filter was black. The old oil was black. In went Mobil 1 V Twin 20-50.
  I lubed the double L shoe linkage and serviced the front brake cable. It was not lubed and didn't give the lever much advantage against the shoes. Meaning = my front brake sucked. It ain't no disc, but it doesn't suck anymore.

  At this point, I don't care how the plug looks. The bike runs great. I believe the stock horsepower rating is 27 -28. This engine is a 535. It feels like it pulls at more than 30 bhp.
 Thanks for the help and the encouragement.
Bill