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Lectron Carburetor anyone?

clcustom1911

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  • Oct 23, 2017
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    The River in Arizona
    Way O/T for here (kind of, but not really)

    I just pulled the trigger on a Lectron 4 stroke carb for my Yamaha WR450F.


    Anyone have one on a bike/snow machine and a wanna share their experience?
     
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    I've always ran them on the 2 stroke mx bikes and have been really happy with them. I'd say it's about as good as it gets next to the fuel injected stuff.

    What ever you do, do not fiddle with the factory settings! Install and ride.

    Enjoy 🍻
     
    I ran Lectron Powerjets on my racer, outstanding!
    H2_racer_d copy.jpg
     
    I was pretty heavy into supermotos between 2005-2010 and ran mostly converted MX bikes (CRF450 and YZF450) and even ran one on my KTM 525SMR. The KTM 525SMR was the bees knees but was plagued with electrical issues so I sold it off after being left stranded too many times and have been on a 2010 Kawasaki Z1000 ever since. I did drop by the dealership to drool over a Husqvarna 701SM last week but I'm too cheap to pay $13k for a bike I'm just going to beat the shit out of.
     
    I had a Lectron on my 2004 KTM 300EXC. Overall, very satisfied. Not as strong right off the bottom as the oem carburetor, but driveability was a lot better. The idle wasn't as rock steady as a traditional pilot jet carb, but I didn't spend much time at idle anyway. Fuel mileage increased 50% with no spooge coming from the tailpipe like the oem carb. Very crisp revving, especially combined with a shaved head to get squish down to .050".

    I ran my 2004 38mm Lectron equipped 300 up against my buddy's 2007 stock 300 in a rolling drag race. My bike pulled a bike length on him through each gear despite my 14/50 gearing to his 13/50. He asked me what the hell I did to the bike! Just the Lectron, shaved head, and Gnarly pipe. We swapped bikes to run another rolling drag race and he outran me the same way. He was 40 lbs heavier than me and still pulled the same gap I did on him. He ordered a Lectron when he got back home!

    I sold my 2004, and just picked up a 2019 300XC. I'll try a JD Jetting kit in the stock Mikuni first, but I have a feeling I'm going to end up with Lectron's latest offering they call the Billetron. The Billetron is two generations improved from my original Lectron, reportedly with improved idle manners. I love the clear float bowl on them.
     
    I had one on my 78 Sportster. On that bike it was more of a gas "On/Off" switch. Replaced it with an S&S Super E. Paul Gast "Fast by Gast" is the go-to for Lectrons on bikes.
     
    I had a trx450 r with cam, titanium exhaust, some other shit and could NEVER get the carb running right. Wish I had ditched the factory pos and kept the bike. It was fast, but needed a rear swing arm to keep up with the front long travel and shocks. Fucker was hard to steer without letting off the throttle or throwing weight around. 4" swing arm woulda solved that. Ugh, I hate myself sometimes
     
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    Haha. All I can tell you is they were state of the art in '77-'78. All the top TZ-250 gp riders were using them. Haven't heard of them since. Yes. I'm a fossil.
     
    • Haha
    Reactions: clcustom1911
    Yeah, for me, I chose this because my Wr450f doesn't have a carb due to the previous owner breaking/damaging it while cleaning/tuning/replacing jets/whatever 🤣. Facebook marketplace $1200 buy. It's a project bike. Not looking for super crazy racing magic, just overall reliability for general fun and ease of use. Carb, battery, tires, fluids and we should be at least running. So, we shall see.

    My other bike is 2013 BMW G650GS that putters around just fine and dandy. Got some plans for that one too. Stay tuned 🫡
     
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    A stock Keihin FCR carb works really well, once you jet it right and time the accelerator pump. Check out the Thumper Talk forum if you want to find jetting specs that may be close for your area, as a starting point. Your carb may need mid body gaskets replaced, if you find you can’t get it jetted. There is a set of gaskets on the slide that can be bad too. Some parts that help tuning include a flexible fuel screw (flex jet, must have), and an R&D Powerbowl (not required but helps make fine tuning leak jet easier). Enjoy your WR. Those 5 valve Yamaha motors were bulletproof.

    I never tried a lectron carb for a 4 stroke, but I tried one on a 2 stroke and it made the bike slower.

    Bottom line: Lectron carbs are for people who don’t know how to jet a carb.

    Get a firepower or antigravity battery. Both are good, firepower is cheapest. They’re about 4 pounds lighter than a lead acid.
     
    I had a Lectron on my 2004 KTM 300EXC. Overall, very satisfied. Not as strong right off the bottom as the oem carburetor, but driveability was a lot better. The idle wasn't as rock steady as a traditional pilot jet carb, but I didn't spend much time at idle anyway. Fuel mileage increased 50% with no spooge coming from the tailpipe like the oem carb. Very crisp revving, especially combined with a shaved head to get squish down to .050".

    I ran my 2004 38mm Lectron equipped 300 up against my buddy's 2007 stock 300 in a rolling drag race. My bike pulled a bike length on him through each gear despite my 14/50 gearing to his 13/50. He asked me what the hell I did to the bike! Just the Lectron, shaved head, and Gnarly pipe. We swapped bikes to run another rolling drag race and he outran me the same way. He was 40 lbs heavier than me and still pulled the same gap I did on him. He ordered a Lectron when he got back home!

    I sold my 2004, and just picked up a 2019 300XC. I'll try a JD Jetting kit in the stock Mikuni first, but I have a feeling I'm going to end up with Lectron's latest offering they call the Billetron. The Billetron is two generations improved from my original Lectron, reportedly with improved idle manners. I love the clear float bowl on them.
    I’d recommend a Keihin 36mm PWK if you’re a slower, technical terrain guy, or a 38mm if you ride faster stuff. Get it from JD jetting. Best 2 stroke carb on the planet. Also, don’t ever sell your 2019!!!
     
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    A stock Keihin FCR carb works really well, once you jet it right and time the accelerator pump. Check out the Thumper Talk forum if you want to find jetting specs that may be close for your area, as a starting point. Your carb may need mid body gaskets replaced, if you find you can’t get it jetted. There is a set of gaskets on the slide that can be bad too. Some parts that help tuning include a flexible fuel screw (flex jet, must have), and an R&D Powerbowl (not required but helps make fine tuning leak jet easier). Enjoy your WR. Those 5 valve Yamaha motors were bulletproof.

    I never tried a lectron carb for a 4 stroke, but I tried one on a 2 stroke and it made the bike slower.

    Bottom line: Lectron carbs are for people who don’t know how to jet a carb.

    Get a firepower or antigravity battery. Both are good, firepower is cheapest. They’re about 4 pounds lighter than a lead acid.
    Excellent info. Thank you.
     
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    I had a Lectron on my 2004 KTM 300EXC. Overall, very satisfied. Not as strong right off the bottom as the oem carburetor, but driveability was a lot better. The idle wasn't as rock steady as a traditional pilot jet carb, but I didn't spend much time at idle anyway. Fuel mileage increased 50% with no spooge coming from the tailpipe like the oem carb. Very crisp revving, especially combined with a shaved head to get squish down to .050".

    I ran my 2004 38mm Lectron equipped 300 up against my buddy's 2007 stock 300 in a rolling drag race. My bike pulled a bike length on him through each gear despite my 14/50 gearing to his 13/50. He asked me what the hell I did to the bike! Just the Lectron, shaved head, and Gnarly pipe. We swapped bikes to run another rolling drag race and he outran me the same way. He was 40 lbs heavier than me and still pulled the same gap I did on him. He ordered a Lectron when he got back home!

    I sold my 2004, and just picked up a 2019 300XC. I'll try a JD Jetting kit in the stock Mikuni first, but I have a feeling I'm going to end up with Lectron's latest offering they call the Billetron. The Billetron is two generations improved from my original Lectron, reportedly with improved idle manners. I love the clear float bowl on them.
    I was lucky enough to pick up 2019 Husqvarna TX300 about 6 months ago that only had 8 hours on it, which is the last year for the carb on TX and XC line.
    I didn't mess with the stock Mikuni, but rather pulled it off and installed a Lectron. I did this because we ride anywhere between 4,000 and 10,000 feet and didn't want to mess with jet changes. Fuel milage is also an issue and the Lectron simply gives more range per tank. I don't have exact numbers here as the bike is still pretty new to me, but one of our longest rides allowed me to get 79 miles out of a full tank. Disclaimer: about 30 percent of this ride was 2 track/dirt road getting to and from the fun single track, but still that's a LONG ride for me and I'm quite happy with the fuel economy.
    I had to fiddle with the initial set up and even called Lectron to discuss what is best described as a "Fluttery" low end when the throttle is just ever so slightly cracked and under a light load. It does clean up immediatly with just the slightest bit of throttle and or engine load. It's kinda weird because it goes from "Fluttery" to clean and crisp in an instant which gives an ON/Off sensation. These Lectrons don't have the typical pilot jet so I think this is what's causing issue. After calling Lectron to discuss they sent me 2 different rods to try (free of charge) and I ended up installing a 5:1 which really helped. Installed it, tuned the rod a bit to lean it out and it's been pretty darn good. Lectron customer service was great to work with and I have no complaints.
    Interested to hear how the Lectron performs on a four stroke....Good Luck!!
     
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    Yes the Lectrons came back into favor with the KTM off-road crowd. I’ve read that they do better with elevation changes and fuel economy. Plus the stock jetting for the 2017+ 2-strokes were so far off from the factory that guys were throwing $400 Lectrons on instead of fighting the oem carb. I had one for my Suzuki RM144 race bike but it ended up being slower and more mellow than my jetted Mikuni TMX. I’ve jetted race 2-strokes since 1997 and the Lectron is definitely a compromise in all-out performance for some flexibility.
     
    Yeah, for me, I chose this because my Wr450f doesn't have a carb due to the previous owner breaking/damaging it while cleaning/tuning/replacing jets/whatever 🤣. Facebook marketplace $1200 buy. It's a project bike. Not looking for super crazy racing magic, just overall reliability for general fun and ease of use. Carb, battery, tires, fluids and we should be at least running. So, we shall see.

    My other bike is 2013 BMW G650GS that putters around just fine and dandy. Got some plans for that one too. Stay tuned 🫡
    If whoever you bought the bike from didn’t know how to adjust a carb make sure you check the top end and valves. The valves on Yamaha 450s wear tight and make for hard cold starts.
     
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    If whoever you bought the bike from didn’t know how to adjust a carb make sure you check the top end and valves. The valves on Yamaha 450s wear tight and make for hard cold starts.
    This right here. The titanium intake valves that are in common use in these hyper power 450s constantly rise in the head due to valve face wear into the seats. I once had a KTM 450 that went to just about zero intake valve clearance 3 times during my ownership. A common trait when intake valve clearance wasn't enough was extended crank/hard starting. I converted over to the 300 2-stroke after that and never looked back. I'd rather do a 2-stroke top end every 100 hours vs pulling cams on a 4 stroke to change out valve shims every 15-20 hours.
     
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    This right here. The titanium intake valves that are in common use in these hyper power 450s constantly rise in the head due to valve face wear into the seats. I once had a KTM 450 that went to just about zero intake valve clearance 3 times during my ownership. A common trait when intake valve clearance wasn't enough was extended crank/hard starting. I converted over to the 300 2-stroke after that and never looked back. I'd rather do a 2-stroke top end every 100 hours vs pulling cams on a 4 stroke to change out valve shims every 15-20 hours.
    The valves were definitely an issue on the early MX 4 strokes, but they don’t really have that issue anymore, unless you’re riding a 250f and bouncing it off the rev limiter for its whole life… or not keeping the air filter clean.
     
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    Plus the stock jetting for the 2017+ 2-strokes were so far off from the factory that guys were throwing $400 Lectrons on instead of fighting the oem carb.

    Not accurate. Take a look at some pictures from when guys like Graham Jarvis were racing on the 2017-2019 300’s and you’ll see Mikuni’s.

    I’ll say it again: people don’t know how to jet a carb. My Mikuni ran really well on my 300 after fiddling with it. I will say it is a little more finicky to get there. That being said, I still like the Keihin PWK best, especially when combined with a STIC metering block.
     
    Not accurate. Take a look at some pictures from when guys like Graham Jarvis were racing on the 2017-2019 300’s and you’ll see Mikuni’s.

    I’ll say it again: people don’t know how to jet a carb. My Mikuni ran really well on my 300 after fiddling with it. I will say it is a little more finicky to get there. That being said, I still like the Keihin PWK best, especially when combined with a STIC metering block.
    I haven’t personally battled the KTM jetting but there is a 31 page/900 reply thread on Vital specifically for the carb settings. When people in mass are trying Kawasaki slides/Yamaha needles/Stic blocks etc. there is definitely an issue. It literally created its own little aftermarket. I’ve ridden 125 and 250 2-strokes from 97 and still do today and never thought of drastic carb swaps.
     
    I haven’t personally battled the KTM jetting but there is a 31 page/900 reply thread on Vital specifically for the carb settings. When people in mass are trying Kawasaki slides/Yamaha needles/Stic blocks etc. there is definitely an issue. It literally created its own little aftermarket. I’ve ridden 125 and 250 2-strokes from 97 and still do today and never thought of drastic carb swaps.
    Neat. There’s also 900 page jetting spec threads for every other 2 stroke out there too. You’re dealing with people who didn’t trust the manufacturer oil ratio of 60:1, which is what the jetting specs were built around for the 2017+ 250/300 engines. This has an effect on overall jetting. So you can’t mix 32:1 or 40:1 and run the same jetting specs meant for 60:1 and expect it to run the same. There’s probably 10 MXA articles pointing to this as well with their test bikes. This is what a lot of people are doing, because many can’t let go of running 32:1 in our bikes when we were kids. Oils have come a long way since then. Again, you’re also dealing with people who don’t know how to jet, don’t understand what each jet effects, and don’t want to take the time to learn/test. The easy button is to take to the internet and let someone else figure it out. Kind of like lazy people do with reloading… You also have to remember that the manufacturer is going to give you richer than needed specs so you don’t burn up your motor. You can thank the lawyers for that.

    I do agree that the slide they spec’d wasn’t the best. You know what fixed it? A few swipes with a triangle file.
     
    Neat. There’s also 900 page jetting spec threads for every other 2 stroke out there too. You’re dealing with people who didn’t trust the manufacturer oil ratio of 60:1, which is what the jetting specs were built around for the 2017+ 250/300 engines. This has an effect on overall jetting. So you can’t mix 32:1 or 40:1 and run the same jetting specs meant for 60:1 and expect it to run the same. There’s probably 10 MXA articles pointing to this as well with their test bikes. This is what a lot of people are doing, because many can’t let go of running 32:1 in our bikes when we were kids. Oils have come a long way since then. Again, you’re also dealing with people who don’t know how to jet, don’t understand what each jet effects, and don’t want to take the time to learn/test. The easy button is to take to the internet and let someone else figure it out. Kind of like lazy people do with reloading… You also have to remember that the manufacturer is going to give you richer than needed specs so you don’t burn up your motor. You can thank the lawyers for that.

    I do agree that the slide they spec’d wasn’t the best. You know what fixed it? A few swipes with a triangle file.
    Interesting that you mention a few swipes with a triangle file on the slide. I have been reading 100s of forum pages detailing the Graham Jarvis mechanic's mod for the Mikuni TMX carbs. It seems that making the slide cutaway larger at the bottom center of the slide creates a stronger airflow signal around the pilot circuits. A lot of folks have reported that this mod virtually eliminated the stutter from idle to 1/8 throttle. I'm getting ready to do it to the Mikuni on my 2019 300XC along with the JD Jetting kit.

    The Keihin carbs look to have some airflow wings in the bottom of the throat that clean up and channel air to the bottom center of the slide. Perhaps this is why they tend to have better driveability manners off the bottom vs the Mikuni.
     
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    Not accurate. Take a look at some pictures from when guys like Graham Jarvis were racing on the 2017-2019 300’s and you’ll see Mikuni’s.

    I’ll say it again: people don’t know how to jet a carb. My Mikuni ran really well on my 300 after fiddling with it. I will say it is a little more finicky to get there. That being said, I still like the Keihin PWK best, especially when combined with a STIC metering block.
    Yep, there are a lot of people that have issues tuning a carb. Either they don’t want to hassle with it or simply inept or whatever the reason, that’s where the Lectron and Smart Carb become attractive. I immediately went to a Lectron due to gas mileage and our big elevation changes during a ride, but I’ve got to be honest, I didn’t give the Mikuni a chance.
    Maybe I’ll get the JD jet kit and do the simple mods and see how it performs. When you hear a well tuned carbureted 2 stroke, it’s like music!
     
    Interesting that you mention a few swipes with a triangle file on the slide. I have been reading 100s of forum pages detailing the Graham Jarvis mechanic's mod for the Mikuni TMX carbs. It seems that making the slide cutaway larger at the bottom center of the slide creates a stronger airflow signal around the pilot circuits. A lot of folks have reported that this mod virtually eliminated the stutter from idle to 1/8 throttle. I'm getting ready to do it to the Mikuni on my 2019 300XC along with the JD Jetting kit.

    The Keihin carbs look to have some airflow wings in the bottom of the throat that clean up and channel air to the bottom center of the slide. Perhaps this is why they tend to have better driveability manners off the bottom vs the Mikuni.
    It makes a big difference. I love free mods.

    You hit the nail on why the PWK runs better than the Mikuni. The air wings are where it’s at.
     
    Ok, we’re definitely not arguing over the merits of a well tuned standard carb. I sold my Lectron and kept the Mikuni TMXs because I ride MX at sea level and wanted more hit and performance. I was giving the OP a little backstory on why Lectron had a resurgence in the off-road community. It was the KTM/Husky 2-strokes, not the FCR carbed Yamaha that he has. For $800, I’m not sure I’d spend the money for the Lectron. I’m not tuning in the snobike world so maybe I’m way off.
    The aftermarket world exists largely because consumers are too lazy or unskilled to do a far cheaper solution. Without knowing your background, I’d assume you’ve logged a bunch of miles and tuned a lot of carbs. It’s equivalent of George Gardner of GAP saying he can tune a stock REM700 trigger to be better than a $200 Trigger Tech. He’s probably right but most guys would rather spend the money and get a cool sticker.
     
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    Heyo guys,
    So i´ve bought this Lectron GEN 2 Carb for my WR450F 2005 here in Europe last year in january and i didnt get it running well since that.
    As you mentioned i told em all my settings and so on bla bla, have to mention first: Im not that good with carbs tho, got my FCR running well but it was very old and worn out (gas slide kept stucking when going off the throttle, cause the slide and housing was worn out etc.) and i wanted to try something new and stepped about that exact page that you posted in here first message @clcustom1911 .
    I got it and first things first i broke my IFS housing (Idle fuel screw) because i just turned it a lil bit too far inside, had to send it back to get a new housing. THEY COVERED THE SHIPPING COSTS THO! Very grateful for that!

    Should you really not change the stock settings? With these i dont have the best starting behaviour even when its warm outside (20-35 °C , classic summer...) It had insane decellaration popping aswell, so i decided to lean it out a bit... it´s gotten way better BUT at 60-70% gas (prolly around where the Power jet opens up to deliver extra fuel) the bike is gasping and jumping and jucking around (You could only ride before Power came, or with full throttle or atleast 85-90%).
    After trying to set that thing up and spending about 20-40 hours just driving around and changing the settings trying to get anywhere because i couldnt stand it anymore (Either i had that problem i just mentioned but a good Idle or if that part of the throttle range was good, the idle was so horrible i couldnt get it started after it stood for 2 days) i legit left the bike in the gutter after test riding and setting it for half a year here and there sometime.
    Its in my garage now and i feel the pain that i cant ride it and im probably too dumb to set that thing right, cause i only hear very positive news from people buying that new GEN 2 carb that i bought and have only had issues with by now.

    ANY TIPS for a 21 year old wannabe mechanic supermoto rider?
    im really thinking about going back to stock and just trying it all again from the beginning.. cause i wanna ride that bike againThanks in advance...
     

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