125-200cc Lectron carbs

So I keep hearing about lectron carbs being the way forward

So I looked into a uk seller and a 36mm lectron with cable and machined spigot and bell mouth for £344 pounds

Or the carb alone with no machining and no cable for £288

This will be going on my 125 sms

I do plan on a bbk either 144 or 165 but will be stock for a while

Does all This sound correct? Price wise I was hoping it would come in Under 300 so is the pricing about right uk guys?

Any help much appreciated

Ahh but i got stung £70 import fee kelly so its about right. I would buy one again if i had another bike that needed one, where in uk are you?? If your midlands area then potentially have a weekend swap carbs an see if you like it.

Im all the way down by gatwick

from whzt i have read the lectrons are tbe way to go


i now have to figure out if the removing of the tps will cause oil pump issues as its electronic

Personally i would get the jetting sorted, not bugger about with tps and have less headache with potential problems later
Buut thata just me. Whats wrong with the sm bad boy?

Thr bike runs spot on jetting wise it seems, im yet to take it out for a spin nkw the clcoks been replaced too see if my pv now works

but the sms and wre come with measly 28mm carbs and i think the engine would benefit grewtly from a bigger carb

I swapped an rs 125 28mm carb for a 34 without issue and that had tps but the oil pump was mechanical whereas the sms is electrical so i assume it alters oil flow depending on the tps sensor?

Nothing wrong with the SM except that stock gearing is way to far spread out for my liking.

the 4th gear on the SM is the same as the 6th on my WR.

with a little head wind the bike drops in speed and you have to shift back.

also when shifting up gears it is not keeping the engine in its power band.

original I would change the sprockets intermediately to a 12-50 or a 13-52 you would have still enough speed to be aloud on a motor way but in the city its a much quicker ride

Again I am spoiled with a WR165 so I comparing the SM with that one.


I am on the same route to get the SM a pep up treatment.

I would think that a 165 on the SM would be perfect with the gearing in mind for the road

still would consider a bigger rear sprocket (14-52), the first gear would be a real easy wheely popper ( just twist the throttle)

I am still breaking my head over the TPS sensor yet the advantage of the lectron wins it over the auto lube if it comes to a trivial point.

I looking into how i can keep the TPS sensor on the lectron fitted carb

the sensor is simply an electrical potentiometer that turns about +/-300 degrees in angle so if the potentiometer can do the same actuated by the throttle cable on the lectron (or even at the throttle tube) its gives the same signal to the system.

The value of the potentiometer is 5 K ohm at full open (indicated in the workshop manual)

Point of attention is that potentiometer can come with a linear curve and a logarithmic curve, I did not find out what is used in the sensor.


when going for a 165 keep in mind that the pipe also have to be changed to get the full potential out of it.

Another point of attention is the ignition (At least I make it a point of attention)

Robert-Jan

Tps's are always linear from my experience. Would be easy to confirm with an ohm meter.

28mm carb to 36mm seems a tad extreme.
Have you found others running carbs set up for bikes twice the cc?

Thanks for the info bud!

Firstly gearing wise I have had to drop my rear sprocket size considerably asy bikes top speed when purchased was only 62mph flat out. I have since dropped it down to a 45t off the top of my head and the front sprocket is either a 14-15t

The bike pulls like an animal even when I had the pv pinned open and I can still easily hit top speed on small roads

As for the 2 stroke I guess pre mix would be the easier way to solve the issue but auto lube is nice on the road.

Currently my bikes stock bar the gearing and a fmf fatty off a cr 125 and the full power kit (all fitted before I got it)

As for carb size the cr and we come with far larger carbs, the sms and wre where made smaller for emissions and uk learner restrictions

My old r's had a 28mm and when you took the carb off it had a large plastic ring on the bell mouth because the bike was originally designed for a 34mm

When I fotted a 34mm the bike became much smooth and a far nicer ride

I just ordered a 36 for mine and it get the 165 treatment

these little bikes are detuned on carb, porting and ignition

so getting a WR/CR cylinder is already a plus bore it out to a 165 is really getting a grin from ear to ear.

the carb is for a big part restricted due to emission regulation and the power restriction to keep this bike in the learner bike category

for sure a 36 mm is fine as on my WR I have a 38 and it runs good (verry good)

Robert-Jan

I am not sure but I think the SM / WRE inlet manifold is also a fair bit different than a WR / CR and this would also need looking into for any type of larger carb swap to be of any great benifits
Lectrons a great carb but a lot of coin to chuck on a SM in my opinion, Ebay is stacked with PWKs ect that would do the job nearly as well as a Lectron and save you a fortune, KTM 125 250 items are jetted almost identicaly and would work straight of the bat. Some even have the tps fitted that maybe could be wired to suit the SM
I sold a TMXX from one of my Huskys to a Guy on here who fitted it to a SM and hes over the moon with it (brand new carb for £50 so would I be ) I still have another one in a box in the workshop along with a few other carbs that would do the job and I would even jet the thing for you if you lived closer
Oh and I paid £28 import duties for the last lectron I got from the USA - First 165 kit I got from Walt I paid £98 and for the exact same second kit was £35 so they would appear to make it up as they go along

You are right that the carb to reed housing union have to be one of a CR/WR besides that its all the same in the engine so far i can see in the manuals (same parts nr's)

TMX is not an option for me (have one on the shelf) it changes to quick its performance because of temp and humidity.

Robert-Jan

Hello bud if you have a suitable carb for the am in all ears? If also need the larger manifold 8-)

The lectrons seem to get great feedback but I'm open to cheaper alternatives

Hi
Yep I will have something buried in a box that will suit your needs, Will dig a few offerings out tomorrow and see if I have a manifold while im at it

Legend thanking you 8-)

Whilst your there if u have a wr front break res for a 2007 or sinilar Id be interested as I have a new new red res cap that won't fit my sm 8-(

Any update on this?

I've been in a similar situation for a while now - I've got a 2007 SM 125 that I've been looking to get some more power out of...

Had a Giannelli exhaust on but now changing to a full DEP setup and next thing I'm looking at is a bigger carb. Recently read up about the Lectron carb but very open to going down the cheaper route of a 36/38mm PWK/TMX etc. I've worked on every aspect of the bike but jetting is out the window for me!

Right now I've got the standard Dellorto 28mm pre-TPS so unfortunately I have this horrid one-into-two throttle cable (one end running to the carb, other to the oil pump). Another complication is the autolube system, it's one of the main reasons I chose this bike so I'd probably want to keep it at all costs, however I have heard the carb boot can be modified to allow an oil inlet?

Anyone out there able to throw me any advice/ideas on a carb setup?