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Smart Carb versus Lectron

Posted: Mon Nov 25, 2019 1:05 pm
by Firebolter
I bought a Smart Carb2 for my TM last week. Got it Friday. Installed in minutes and uses the stock cable that the TM had for the Keihin. I have a Lectron on my 300 XC-W. It required a special cable (MOTION PRO).

Lectron-No jets, uses a flat surface on one side and round on the other side of the needle. The round side faces the intake or air boot. As air is sucked in, the round side of the needle acts like a "wing" and causes the fuel to be sucked "up" the flat side which has a specific grind and shape to it, bike dependent. Comes pre-set but the needle can be adjusted Up or Down to richen or lean the fueling. You have to take the carb top off to adjust the needle length. It does have a Power jet (an external screw adjustment) which is really just a screw that meters fuel from 1/2 throttle up to WFO to keep it rich/add fuel on top when needed. It does have fuel vent lines. It does have a choke. It does have an idle screw. Once you set it up, you are good to go. Only adjust the external Power jet screw a bit when you go above about 6K feet.

Smart Carb2-No jets, uses a flat surface on one side and round on the other side of the needle. The round side faces the intake or air boot. As air is sucked in, the round side of the needle acts like a "wing" and causes the fuel to be sucked "up" the flat side which has a specific grind and shape to it, bike dependent. Comes pre-set but the needle can be adjusted Up or Down to richen or lean the fueling. You can adjust this with no tools, it is externally adjusted on top of the carb with the bike turned off, to adjust the needle length. It has no other adjustment except a choke and an idle screw. It does not have fuel vent lines. Only a float bowl drain line if you wanted to drain the carb, and the fuel line from the tank. It does not spill or vent fuel to the atmosphere. Once you set it up, you are good to go. Mine is nice as delivered.

Both carbs compensate for Altitude/Temp/Humidity (all though Lectron needs a quick power jet screw adjustment for high altitudes), so you get consistent performance across all the variations you could ride in year round. Fuel economy is really a bonus. I can go over 90 miles on a stock tank of gas and not hit reserve. Did that on day 2 of Hammer this year. That is a big bonus for me. You can ask Boom Boom about how my TE-300 Husaberg top end looked after 120 hours running the Lectron, like new. Cylinder still had nice cross hatch marks and rings were in spec. In other words, perfect fueling.

So the Smart carb after I installed it, fired right up and settled in to a nice idle. It was ~45 degrees sat morning and I was very impressed how quick it started on the button, fired up like it was hot. My Lectron when it is that cold, prefers to be started by the kicker until it is warm. I rode it around and it was crisp and very linear, much like the Lectron except the mid range hit was more "Keihin" like. I am sure the fuel economy will be very similar to the Lectron. Very happy with it. Like that is does not vent to the atmosphere and looks like a piece of jewelry on the TM. More testing to come.

Smart Carb is a bit pricey compared to the Lectron. I like them both, but think the simplicity of adjustment on the Smart Carb2 is awesome, no tools needed for any adjustment. Plug and play!

Re: Smart Carb versus Lectron

Posted: Mon Nov 25, 2019 5:23 pm
by gots_a_sol
I've had a Lectron on my Husky for years now. The fuel mileage increase is probably the best thing about it. Also since it is my back up bike and sits a lot, not having to worry about jets getting clogged is a major plus. The clear float bowl is cool too :deal:


At the enduro this weekend, there was a guy on the row ahead of me with a Husky 165 :cheers: He had the same 3 gallon IMS tank as me but the stock carb (mikuni). On the final stretch of trail heading back to the parking/finish area, I came across him stopped on the side of the trail, out of gas, while I still had about .75 - 1 gallon left (which I gave him some to get home with). I had caught up to him in every test and passed, so he wasn't riding any harder than me, it is just the Lectron does get that much better mileage.

Re: Smart Carb versus Lectron

Posted: Mon Nov 25, 2019 7:09 pm
by Firebolter
Yeah the gas mileage is pretty awesome. Day 2 of hammer was alot more road and less trail. We were running alot more on the throttle. 89.6 miles and I was just at the bottom of my shroud on my 300 and not near reserve yet. Could have easily got 110 miles to a stock 2.4 gal KTM tank. Good stuff.

Re: Smart Carb versus Lectron

Posted: Mon Nov 25, 2019 9:02 pm
by Bucho
Good info guys.

Glad to know about increased fuel mileage.

Re: Smart Carb versus Lectron

Posted: Tue Nov 26, 2019 10:23 am
by Laoch
Smart carbs and smart phones, smart cars...all smarter than me. :shrug:
At least with FI I understand how it works.

Re: Smart Carb versus Lectron

Posted: Tue Nov 26, 2019 10:59 am
by Wingfixer
I have a lectron I'll sell ya! :deal:























Fuckin boat anchor. :censored:

Re: Smart Carb versus Lectron

Posted: Tue Nov 26, 2019 12:34 pm
by Firebolter
Wingfixer wrote: Tue Nov 26, 2019 10:59 am I have a lectron I'll sell ya! :deal:






Fuckin boat anchor. :censored:
You "Beta" watch out son! Else you might get "Skinny Jayed" next time we ride together! On purpose! :hi5:

Re: Smart Carb versus Lectron

Posted: Tue Nov 26, 2019 1:55 pm
by smdub
I appreciate the feedback on both!
Wingfixer wrote: Tue Nov 26, 2019 10:59 am Fuckin boat anchor. :censored:
Disclaimer: I'm an engineer and analyze everything.
The Lectron is a good carb fundamentally (I think.) Where I think they go wrong is the needle selection and advertising. It is NOT going to be an install and not-touch type thing for some bikes. I'm going through the issue of a low rpm WOT bog on the 150. They do a TERRIBLE job explaining how the different rods work. Some graphs would be great for example. A way to get custom rods made might be a nice touch. I'm not so sold on the power-jet part either. I think the Smart Carb is a better design. Though is it $300 additional better design, I don't know. Smart Carb appears to do an even worse job of explaining if there are different metering rods available.
I'm going to be riding the 150 this weekend and will give tuning the Lectron another shot now that I understand what/how to adjust. If I can't fix it and I *KNEW* the SC2 would solve my bog I'd buy one. My other alternative is going back to the stock carb. Seems many have figured out how to tune it well w/ a JD(?) kit. I'd give up it running great everywhere except that bog for it running meidocre everywhere w/ worse fuel economy. If I can't fix it, I'm going to dump it and buy an efi bike. Though at the moment its still in the 'challenge' stage of my patience so I humor tinkering w/ it. I don't like being defeated;)

Re: Smart Carb versus Lectron

Posted: Tue Nov 26, 2019 2:44 pm
by Firebolter
smdub wrote: Tue Nov 26, 2019 1:55 pm My other alternative is going back to the stock carb. Seems many have figured out how to tune it well w/ a JD(?) kit.
What is your stock carb? Mikuni? When I was running "traditional" carbs (Airstrykers mostly) JD kits worked great. I went to the Lectron on my 13 Berg TE300 and never looked back. Made 1 adjustment to the needle and then only touched it when I went to Colorado and adjusted the PJ 1/8th of a turn to clean up the mid to top transition at altitude.

I had one of the original smart carbs before the Lectron in 2013, but it was too big and I didn't like how it fit, they took it back no hassles. The SC2's fits my TM like a glove. For me, the fuel economy and the no jetting make grandpa a happy camper, but I don't or have had any of the issues you are talking about either. I ran one on my Husky 165 too and it ripped. Hopefully you'll get it sorted out. Assume you have no air leaks or weird stuff with your airboot? Reeds look okay? Just curious.

Re: Smart Carb versus Lectron

Posted: Tue Nov 26, 2019 3:41 pm
by smdub
Bike had 44hrs & 464mi on it when I bought it. Was Bucho's friend who never rode fast.
No leaks I can find.

I just replaced the stock reeds w/ Vforce4R on everyone's (online) recommendation. The stock reeds are known to have gaps and not seal. In real life that usually isn't a problem as the crankcase pressure pulses will push them sealed, but my problem is at lower rpm where maybe that doesn't happen as effectively. Mine definitely had gaps. The Vforce 4R look perfect. I goofed off here a little in the parking lot after install and can still get it to happen but I may have adjusted the power valve the wrong direction. It definitely starts easier w/ the new reeds.

So as a "can't hurt to try" type modification I bought a RK Tek head and installed last week. Everyone (online) universally agrees it adds bottom end which is never a bad thing (esp on a 150) even if it doesn't help the jetting problem. It definitely reduced the squish band so looking forward to trying it.

Was supposed to go riding last weekend to test/tune but we called it on account of rain. We rescheduled w/ my friends for this Sat. I'm going to have the bikes in the van anyway when we go down to my dad's for Thanksgiving. Hope to get some time to ride it on his property and get another shot tuning it before the big weekend gettogether.