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By: Chris Hodkinson

Flatslides, Roundslides, TMX, PJ, PWK, Air Styker, TaperBore, SmoothBore,etc.... the list goes on and on. Those are just some of the choices for the modern carburetors on today's ATV’s. For years the 2 most popular brands have been Keihin and Mikuni but now there is a 3rd brand called Lectron that is really starting to catch on in today's market.

Lectron has actually been around since 1979 but since the factories don't use them they are a relative unknown. 1999 GNC Pro Champ Doug Gust, 1998-99 Womens Champ Angela Moore, and 2000 Womens Champ Leslie Wells have all used Lectrons on their quads to help propel them to their championships. Tom Carlson of TC Racing has been using these carbs for years now on both 2 and 4 stroke motors. Tom has even went as far as mounting dual Lectron Carbs on Travis Spaders 250R a couple of years ago. Lectrons are not only found in the MX and TT races across the Country. They are also found on the top Drag bikes in the NHRA.

To see how the Lectrons worked we contacted Racer Edge about them. After telling them the mods to our TRX250R and that we want an emphasis on top end power, they recommended the new 38x40 High Velocity Carb with a Power Jet. 38x40---what is this we asked as most carbs that we have dealt with only have 1 number like 36mm or 38mm, but this one has 2. We was told that the "H.V." carbs as they call them are taper bores and have 2 different I.D. sizes. In this case the 40 means that it is 40mm from the Air Filter side of the carb to just past the slide then it is tapered down to 38mm. By doing this the air/gas mixture that is being pulled into the motor picks up speed as it is sucked from the 40mm section to the 38mm section through the Reeds, into the Case, and out the transfers into the cylinder. By increasing the velocity in which the fuel mixture moves you accomplish 2 things. 1) Is that you get better fuel atomization with the faster movement and 2) you can pack more fuel into the case every time the piston goes up. More Air/Fuel = More Power. Also by doing this you have the same Top End power of a Big Carb without the drastic loss of the Throttle response that you normally get with a Big Carb.

Installation

Installation of the Lectron is basically the same as any other big carb on the 250R. You loosen the 2 clamps holding each end of the carb on and remove the old carb and install the new one. Unless your Intake Manifold and Airbox Boot are new you may have to work a little bit to get the rubber to stretch enough to get the bigger carb on. Here are a couple of tricks that we have found to work well. The intake manifold can be put in boiling water for a couple of minutes to soften up the rubber so that it stretches and slides over the carb easier. For the airbox boot you can take your wifes or mothers hair dryer to heat it up while it is on the machine to help stretch it to fit over the carb.

Once everything is clamped on and the throttle cable adjusted you are ready to go. Before we fired up the quad for the safety of our motor we richened up the Powerjet (Mikuni Pilot jet) to the max size that they sent us.

The Lectrons are quite unique to jet. You must first understand that Lectron uses a single threaded metering rod that is tapered. This rod takes  the place of a air screw, pilot jet, needle, and main jet found in a Keihin or Mikuni. This one metering rod is equivalent to about 10 main jets. For idle and low speed tuning you turn the rod in to richen the mix or out to lean the mix. For Midrange tuning you read the 2nd number on the rod. If you want to richen the midrange up you put in a rod with a bigger 2nd number or if you want to lean it out you put in a rod with a smaller number. (ex. #5-2 rod is to rich in the midrange you would replace it with a #5-1 rod).

For top end tuning you use the 1st number on the rod and the Powerjet. If you find that your top end is to rich you can drop down the number on the Powerjet. If this does not solve the problem you will have to change the rod to the next number smaller. (ex. #5-2 rod is to rich on top you would replace it with a #4-2 rod and readjust your powerjet). One small note on the rod also is that the flat side of the rod must always face in towards the engine.   Jetting the Lectron for the first time can be a little troublesome as it is so different then any carb out on the market today. But once you get used to doing it you will never want to jet any other carb again.

Riding

We warmed up the quad and made some jetting runs. After checking the spark plug and verifying our readings with our Digatron ETG/Tach we found we were on the rich side. We put the jetting back in that Racers Edge had sent with the carb and now it is spot on. Better safe then sorry. The time that it took to richen up the jetting is well worth it if you happen to burn down the motor by not doing it.

Now for the fun part. First we went out and did some casual play riding to get a feel for the carb. We were surprised to see how crisp the throttle response was for a big carb. This quad felt as if it had just as good if not better throttle response down low then the 35 PWK Air Stryker that we tried on the quad earlier in the day for a comparison. Seat of the pants testing can be deceiving though so we put it up against our test Banshee to see if what we felt showed up on the drag strip. After doing countless 2nd and 3rd gear roll-ons we found that the 38x40 H.V. Lectron would shoot out quicker and farther then the 35 Air Stryker with a great increase in top end also.

After doing some more high speed runs and collecting Tach Readings as well as race results from running against our Banshee we put back on our 39 PWK that we had on the quad before our Lectron arrived. This is a lot of wrenching in one day but to provide accurate results due to the changing weather from day to day it had to be done.

With the 39 PWK in place we went back out to the drag strip. Doing the same 2nd and 3rd gear roll-ons the throttle response with the 39 PWK just wasn't as good as the Lectron. The race results and tach readings proved that the top speed was about the same between the two carbs but the Lectron carb got up to top speed a lot quicker.

We have taken our Lectron carbed 250R out several times now in various temps and altitudes and the Lectrons do not appear to be affected by the changes in weather as much as the Mikunis and Keihins. For safety purposes we always check our jetting and so far it has stayed just about spot on for our different riding areas where as before we would have to rejet every once and a while. Other features of the Lectron carb are a LUSTROUS NICKEL GUILLOTINE SLIDE - "Slices" the Air Flow for a Positive Shut Down. Extremely hard surface has virtually no wear. FUEL-VU TRANSPARENT FLOAT BOWL - Allows easy view of fuel to check level or contaminates. DUAL-FLOAT SYSTEM - Ensures a precise level under all conditions.  GREATER FUEL ECONOMY.

We were so impressed by the Lectron carb that since our test we have installed 2 sets on 2 modified banshees and we have been very happy with the gains in performance over the previous carb setups. (FTZ 35mm Flatslide Mikunis and Bored Stock carbs) We have also talked to Racers Edge about the high cost of putting big carbs on the Banshees because you have to replace the intake manifolds to accept the bigger carbs. They informed us with the Lectrons you do not have this because there is enough material that they can turn the O.D. of the carb down to fit into the stock intake manifolds. If you would like this done just let them know at the time you place the order. This little service alone can save you about $200.00.

For more information about the Lectron Carbs you can contact them at:

Racer Edge
1580 Forrest St  
Dyersburg, TN.   38024
Phone: 1-888-558-7822

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