Lectron carb tuning guide

[Motosportz]

Tuning a Lectron carburetor guideline...


I have revised this... (6/18/15)

The idle slide adjustment screw is set up to starting point of 2mm – 2.5mm. You can tune from there, if your slide seems to be very high (wide gap of no adjustment left) the engine is more than likely a little rich. If the slide is very low then the bike is more than likely too lean. The slide height can vary from Bike to Bike depending on compression, pipes, fuel etc.
Engine idle should be about 1500 – 2200 RPM

1. Install the carb as sent and fire it up. Get it fully warmed up and cleared out. Evaluate how it runs.
2. You should be about 1-1.5 turns out (see above) on the idle adjustment and it should start and idle fine.
3. If it needs more then 1.5 turns out to maintain a good idle the rod is set to rich, if it idles high it is to lean.
4. Adjust the rod in (rich) or out (lean) in ¼ or (or half turns if it seems way out of whack) to get the idle and starting sorted as per idle adjustment range above.
5. Once you have the bike starting and idling nice it should have snappy throttle when sitting. At this point you are done adjusting the rod, don’t touch it any more.
6. Then go ride the bike. Should have good throttle response and pickup at this point. Then get into the throttle more then half way to full throttle and note the sound and feel of the motor. If it has what I call “smokers voice”, a harsh crackly note and does not accelerate hard and struggles you are lean on top. Turn the adjustable powerjet out ¼ turn increments and test again until the crackly response on top goes away. Do not adjust past 2.5-3 turns out. If you need to do this contact me. If your top end is boggy / flat and lifeless but not crackly when on the gas hard you are rich. Turn the powerjet adjuster in to lean it out until this flat feeling goes away under full throttle.

If you have any running issues please do these things above and then if you are still not 100% satisfied please post here with what is going on so we can sort these things out.

All this said I have been doing a bunch of custom rod testing based on my experiences and feedback from customers. I spent 4 hours the other day working on some things and found some very rewarding and interesting results. Not ready to let the cat out of the bag as I want to do some more testing but think I have sorted some things out nicely and taken this to the next level. The 125/144/165 motors have some unique needs and my custom rod addresses those and WOW the response and performance are amazing. Will let you guys know more about this soon. Great stuff. Takes a great carb to the next level for our little tiddlers.

Thanks
Kelly
Motosportz

 

[Motosportz]

BTW don't get upset if I edit or delete posts in this thread as i want to keep it really clean and informational. Please only post pertinent info and issues needing resolving here.

thanks.

 

[huskybear]

Tuning a Lectron carburetor guideline...

1. Install the carb as sent and fire it up. Get it fully warmed up and cleared out. Evaluate how it runs.
2. You should be about 1-1.5 turns out on the idle adjustment and it should start and idle fine.
3. If it needs more then 1.5 turns out to maintain a good idle the rod is set to rich, if it idles high it is to lean.
4. Adjust the rod in (rich) or out (lean) in ¼ or (or half turns if it seems way out of whack) to get the idle and starting sorted as per idle adjustment range above.
5. Once you have the bike starting and idling nice it should have snappy throttle when sitting. At this point you are done adjusting the rod, don’t touch it any more.
6. Then go ride the bike. Should have good throttle response and pickup at this point. Then get into the throttle more then half way to full throttle and note the sound and feel of the motor. If it has what I call “smokers voice”, a harsh crackly note and does not accelerate hard and struggles you are lean on top. Turn the adjustable powerjet out ¼ turn increments and test again until the crackly response on top goes away. Do not adjust past 2.5-3 turns out. If you need to do this contact me. If your top end is boggy / flat and lifeless but not crackly when on the gas hard you are rich. Turn the powerjet adjuster in to lean it out until this flat feeling goes away under full throttle.

If you have any running issues please do these things above and then if you are still not 100% satisfied please post here with what is going on so we can sort these things out.

All this said I have been doing a bunch of custom rod testing based on my experiences and feedback from customers. I spent 4 hours the other day working on some things and found some very rewarding and interesting results. Not ready to let the cat out of the bag as I want to do some more testing but think I have sorted some things out nicely and taken this to the next level. The 125/144/165 motors have some unique needs and my custom rod addresses those and WOW the response and performance are amazing. Will let you guys know more about this soon. Great stuff. Takes a great carb to the next level for our little tiddlers.

Thanks
Kelly
Motosportz

You are spot on bro! My idle screw is at 1.5 turns out and the rod is in the sweet spot.my power -jet screw is at 2.5 turns out.Runs great!

 

[surfer1100]

Thanks for this, does make it a little more straight forward.

Now to my issues...doh

So I followed the guide starting with the settings I had left off on save for setting the idle screw at 1.5 turns out from fully closed.

Started to go leaner on the rod from where I was(pretty sure within 1/4 turn of original settings) in 1/4 turn increments...

Experienced little change in idle until maybe the 5th/6th adjustment leaner, where the idle was way screaming high enough that the kill switch would barely work.

That being said, at each adjustment the idle was higher than I would like, and each time I would end up 2.5-3 turns out to make it settle.

It did run very crisp and clean and was quite snappy and very little smoke at the second to last adjustment leaner.

BUT the idle screw was at 3 turns out AND at a lean setting.

So I started richening the rod by 1/4 turns making sure the idle screw was at 1.5 out each time. After 10-12 1/4 turns richer the idle was at a nice level similar to what I am use to.

BUT the bike is super rich and smoking and misting oil everywhere(something this bike has never done) and of course not snappy and has that rich flat bog.

This final setting was spot on with your 49.5mm mark.

I then compared the slide and rod with my cousins Gas gas 125, which he claims is very crisp and likes it a lot.

His was about 50.5-51mm, so I adjusted mine accordingly. ended up being 1.25 turns leaner on the rod. Revs better and idles high at 1.5 turns, of course if I turn it out to 2.5/3 it's better. Still spits some oil(probably left over oil from super rich).



SO basically can't get the bike to idle and rev out clean if idle screw is set at 1.5. It runs near perfect as I lean it out, but needs idle to be set at 2.5-3.5 turns out.

Somethings I should mention are that the machining on the carbs is rather abrasive, especially on the slides. Both of these carbs have less than a hour run time and the slides are already looking beat up, grooved, etc. Also my slide appears to be ever so slightly larger( say 0.5 mm longer) and the edges on the other carb seem to be machined slightly different as well( more rounded edges at the 4 corners, etc). Both bikes have the 3-1XL rod and are also receiving scratches already with the low use.

I am not upset and know carbs can be finicky, just dumbfounded and confused at why I am having so much trouble tuning this bike. I tuned the TMX carb on my 07 125 as a complete newbie to jetting faster than this thing!! haha

 

[Motosportz]

Interesting. Give me the full specs on the bike, what bike, size, modifications, type of fuel etc. Nothing sounds right here. Are you saying there is no way to adjust the rod so it starts / idles nice at 1-1.5 turns out on the idle adjustment regardless of how it runs at above 13rd throttle?

"His was about 50.5-51mm, so I adjusted mine accordingly. ended up being 1.25 turns leaner on the rod. Revs better and idles high at 1.5 turns, of course if I turn it out to 2.5/3 it's better. Still spits some oil(probably left over oil from super rich)"

Sounds like you are lean on the rod. If you went richer then you could drop your idle adjustment down.

Also oil spooge means absolutely nothing when it comes to getting. Some oils spooge WAY more than others. Flash points, fuel quality, and lots of other factors affect this.

How does your plug look?

Again, dont focus on the mid and top at all, get the rod right then move on from there.

Let me know.

BTW i have installed these carbs or been there for the first ride on someone elses bike on about 6 bikes now. None of them had much of any issues. Some slight tweaking. Something is up here. Did you try installing the GG125 Lectron that works well on your bike to see? Walt has three, Tim has three and no real issues.

thanks
Kelly

 

[surfer1100]

Interesting. Give me the full specs on the bike, what bike, size, modifications, type of fuel etc. Nothing sounds right here. Are you saying there is no way to adjust the rod so it starts / idles nice at 1-1.5 turns out on the idle adjustment regardless of how it runs at above 13rd throttle?

2003 TM Racing 125 MX, replaced top-end 20-25 hours ago with OEM parts from Taskys. 93 octane with Motul 800 32:1. Has a CR 125 stator with JD ignition.

Was running exceptional with stock carb except for low end, bike is a screamer, not a lugger. YES, if I keep the idle screw at 1.5 it only idles nicely at a rich setting where it spits oil and needs lots of clutch to get going. Am only snapping the throttle from 0-1/3 throttle in first gear.

Bike runs great with instant/crisp response off idle at the leaner end of the scale but idle screw has to be at 2.5+ turns out.

"His was about 50.5-51mm, so I adjusted mine accordingly. ended up being 1.25 turns leaner on the rod. Revs better and idles high at 1.5 turns, of course if I turn it out to 2.5/3 it's better. Still spits some oil(probably left over oil from super rich)"

What I meant here, was after going all the way rich(and just by chance being at your setting of 49.5mm and it idling nicely but running poorly), I compared to the other rod length on the GasGas and turned mine back leaner 1.25 turns, which is where it is at now. It runs ok but idles high at 1.5 turns and prefers to be out

Sounds like you are lean on the rod. If you went richer then you could drop your idle adjustment down.

Again, only the outliers of the adjusment range(3+ turns on the rod) I've done seems to effect idle. Meaning, say I am at the leanest position I've tried with the idle at 1.5 and screaming...it takes 1/4 turn on the rod to not scream but still be high, and another 2+ full turns richer before idle lowers from high to somewhat respectable.

Also oil spooge means absolutely nothing when it comes to getting. Some oils spooge WAY more than others. Flash points, fuel quality, and lots of other factors affect this.

Only reason I mentioned spooge, is because all of my Husky 125s would spooge, but this TM has NEVER spooged at all until today.

Cousin won't let me try his carb, doesn't want me to jinx it!!! I think the difference in slide size(length from top to bottom), may be enough that is causing the differences???

I have had the plug foul twice now when I adjust richer to get the idle reasonable at 1.5 turns. The two times it wouldn't start were during richer settings and the plug fouled. So dark brown/black.

 

[kan3]

Thought I'd make a post here to see what you thought. I originally made a post in your other thread but since then I've had about 4 hours of testing on actual trails.

Bike is a 05 Eric Gorr yz144 setup for pump gas running on a 36mm lectron. Gas is 90oct with no ethanol.

I'm sitting at about 1.5T out on the rod from stock and I get a nice 1400-1500rpm idle at 1.5-1.6T out on the idle screw. I tested everything from stock to 2T out from stock on the rod and settled on that setting. 0-.5T out was super rich and would foul plugs at idle and 2T out had the idle screw at 2-2.25T out to get it down.

My only real issue seems to be a so so throttle response when just creeping along at idle and whacking the throttle. I also noticed if I whack the throttle open the PJ plays a large roll. Right now it's at 1/4T out and anything more will have the bike do this in out bog type of thing where it struggles to go. If I close the PJ any more then it revs through but slowly and lacking power. If I'm moving around at 1/8th throttle or so and whack it open then it hauls. When testing full throttle at 3-4th gear then 1/4-1/2T produces similar results and has a clean pull through the top and revs really nice. Where as .75-1.0T out would give you a bit of a on/off type of feeling.

The only other thing that's weird is that I have a crackle at 1/4 throttle at anything rod/PJ setting. Didn't matter if it was super rich or lean it's always there. I'm not sure if it's the carb so I'm going to try a few different things.

 

[Motosportz]

You guys should feel free to call Lectron and talk to Kevin about these issues. He is swamped but very nice and knowledgeable. This needs sorted as i have not personally experienced any such running issues on these carbs. Rode with buddy blake this weekend, we both have Lectrons on or 165's and both run fantastic. Jakes bikes does as well. I just have not seen one personally that does not so have a hard time understanding why. I am absolutly not saying your not having these issues I just don't know how to help you further as I have not had to tackle these same issues.

I did design a small bore custom rod Lectron will be copying to my specs for the 125/165 bikes. More info on that soon.

 

[wallybean]

Hi Kelly,

Any idea when Kevin can get those produced for you? When I ground mine like yours it was a big help and boost from mid to top at 1/2 to full throttle. I was able to go back from 2.5T out on the PJ to 1T and pulls much faster and harder in that region. I think prior to this there was the slightest delay waiting for the PJ to kick in and the PJ doesn't atomize as well. Just an FYI mine idles perfect at 3.0T out on the idle screw and is clean and fast everywhere. Plug burns a perfect light tan no matter where I am running it before a chop. You can whack my throttle at any point in any gear and get instant response. You damn well better be prepared for that on the 165 too.

 

[Motosportz]

Hi Kelly,

Any idea when Kevin can get those produced for you? When I ground mine like yours it was a big help and boost from mid to top at 1/2 to full throttle. I was able to go back from 2.5T out on the PJ to 1T and pulls much faster and harder in that region. I think prior to this there was the slightest delay waiting for the PJ to kick in and the PJ doesn't atomize as well. Just an FYI mine idles perfect at 3.0T out on the idle screw and is clean and fast everywhere. Plug burns a perfect light tan no matter where I am running it before a chop. You can whack my throttle at any point in any gear and get instant response. You damn well better be prepared for that on the 165 too.

I just posted this...

http://www.cafehusky.com/threads/lectron-125-144-165-custom-rods-coming.32268/

A few weeks and we will have them. Don't want to give up my custom rod before this weekends race.

 

[Aviduser]

Just got my lectron idling nicely at 1.25 turns out on the idle screw. I had to adjust the metering rod 1 full turn richer to acheive this.

Are you sure your instructions are worded correct Kelly? I found turning the idle screw out slowed the idle therefore richening the mixture. I started out going backwards at first following this guide. Leaning the bike out to where it would barely start/idle".

Now that its set properly the bike starts first kick and idles beautifully! Stoked cant wait to ride and dial in the power jet.

Example

"If it needs more then 1.5 turns out to maintain a good idle the rod is set to rich, if it idles high it is to lean.


For ppl having trouble I found 1 1/4 turn richer from where the bike hangs cracking the throttle (lean) was spot on

Just wanted to clarify. Thanks for the carb!

 

[surfer1100]

I spoke to Kevin at Lectron as we were having separate issues on both carbs. (FYI make sure to check your slide every once in a while. the material is very soft and one carb developed a notch and would cause the throttle to stick wide open yay haha. If yours has any notching, Kevin recommended scotch brite pads to smooth it out and install slide soaked in WD40)



When we were talking about my jetting troubles, he said he didn't care where the idle screw was set at, as long as its in the threads as "every carb is different from the next as is every bike let alone their reactions to the carb"... He said obviously if the screw is closed or 7 turns out, then you need to adjust accordingly, etc.

Fouled 4 plugs in total to get where it is now. FYI pushing a bike back to the truck in full gear in the mud is not fun!!! haha

I still haven't started messing with the Powerjet, but I'd say I'm 90% there.

Current settings are at 3.5 turns leaner than the 49.5mm setting on the rod and idle screw at 3-3.5 turns out.

Pulls clean except for a couple hitches. Plug is finally dry and brown, but it has a definitive line down the center of the porcelain with one side looking perfect (medium brown) and the other maybe slightly lean (tan color). Anyone familiar with this differentiation on the plug?? Maybe need to richen the power jet?

 

[Aviduser]

I think kelly is pretty close with the 1.5 turns out on idle. It took me a 1/4 or half turn past the bike running fine on idle to get there. It liked to be at 2 turns out. But I'd rather have it running a bit rich for when u have a wfo run to throttle chop.

Never fouled a plug in 4 years of riding cr125's, I'd be suprised if I do now.

 

[Blakelpd5]

Fouled 4 plugs in total to get where it is now. FYI pushing a bike back to the truck in full gear in the mud is not fun!!! haha

Haha, i never leave the truck without a spare plug, because I hate pushing a bike, almost as much as running.

Rode my bike 99.4 miles today in an ISDE, a FAST ISDE, and had to turn the powerjet out 1/4 turn because it seemed lean, and was bogging WFO in 6th (which is about 45-50mph with my gearing)

Other than that, the bike ran freaking amazing...

 

[DaveG321]

Has anyone with the WB165 was lucky enouph not to have to adjust the meetering rod? So far I only turned down my idle.I still have a slight bog which is due to my bike being a WR ,other than that it rips and sounds strong wright up to the top end.

 

[Motosportz]

Rode my bike 99.4 miles today in an ISDE, a FAST ISDE, and had to turn the powerjet out 1/4 turn because it seemed lean, and was bogging WFO in 6th (which is about 45-50mph with my gearing)

Other than that, the bike ran freaking amazing...

That was fun and you were rockin. Had a really good time and my bike ran fantastic as well. Was amazed how the 165/Lectron would pull in the deep silt in 6th.

 

[Motosportz]

I spoke to Kevin at Lectron as we were having separate issues on both carbs. (FYI make sure to check your slide every once in a while. the material is very soft and one carb developed a notch and would cause the throttle to stick wide open yay haha. If yours has any notching, Kevin recommended scotch brite pads to smooth it out and install slide soaked in WD40)



When we were talking about my jetting troubles, he said he didn't care where the idle screw was set at, as long as its in the threads as "every carb is different from the next as is every bike let alone their reactions to the carb"... He said obviously if the screw is closed or 7 turns out, then you need to adjust accordingly, etc.

Fouled 4 plugs in total to get where it is now. FYI pushing a bike back to the truck in full gear in the mud is not fun!!! haha

I still haven't started messing with the Powerjet, but I'd say I'm 90% there.

Current settings are at 3.5 turns leaner than the 49.5mm setting on the rod and idle screw at 3-3.5 turns out.

Pulls clean except for a couple hitches. Plug is finally dry and brown, but it has a definitive line down the center of the porcelain with one side looking perfect (medium brown) and the other maybe slightly lean (tan color). Anyone familiar with this differentiation on the plug?? Maybe need to richen the power jet?

so pretty much sorted? Wonder why you ahve to run such drastically different settings than most? Are you running race gas?

 

[surfer1100]

Yes, I would say 90% sorted, still seems to change day to day( was real snappy on the bottom few days back, yesterday seemed way softer). Didn't want to run well at slower speeds.

I'm running pump premium @ 32:1 Motul 800.

I'm guessing it's just the TM engine, supposedly 16:1 compression ratio or something crazy like that.

 

[Motosportz]

Yes, I would say 90% sorted, still seems to change day to day( was real snappy on the bottom few days back, yesterday seemed way softer). Didn't want to run well at slower speeds.

I'm running pump premium @ 32:1 Motul 800.

I'm guessing it's just the TM engine, supposedly 16:1 compression ratio or something crazy like that.

Yeah, I'm confused with all the issues you are having. Seems strange.

 

[Soviet]

Kinda seems like an intake leak or something funky. to have a carb running so inconsistent one day to the next leads me to believe something is wrong.