KDXRIDER.NET

I have a 2000 CR125 with an e series KDX motor. The e series motor is basically stock, runs an FMF Gnarly pipe and Turbine II silencer. Other than that, it's fairly stock motor wise. The jetting on the stock carb is finicky and frankly, that carb has a lot of tool wear in addition to being over 25 years old so for that an other reasons, I'm looking at doing a lectron replacement if only it will save me having to remove it to adjust. That alone is a lifesaver.

In looking at using a lectrons, there's not likely a way that a 34mm lectron will fit without cutting areas I'm unwilling to cut. I CAN...however, potentially put in a 30mm. Same carb as in the KTM freeride. From a performance standpoint, this might actually be ideal. I want essentially a trials like power delivery in an MX frame. A small carb might further this goal..however. I see folks have run 30's on KDX's and it no doubt impacts top end a lot but I'm trying to get a sense of how badly. Personally, a lot of grunt from closed to half throttle is something I prefer to any amount of top end.

Anyone with positive or negative experience running either a lectron or a tiny carb (or both) ?

You and I think alike. While I have no experience with the scenario you describe, I run a 26mm Keihn carb on my 250 Maico for just that reason.

IIRC, the KDX SR versions run a 28mm carb, so you might be able get some information by researching their performance.

My Kdx220 is the SR model which used to have the 28mm carb but previous owner changed it to 36mm. I've since changed it to 33mm and much happier. I'd like to go back to the 28mm if I can find the air boots, I rarely go past 1/4 throttle. As suggestion by a cheap copy keihin from China then you can decide yourself if the top end is enough for you. If going to 28mm I would keep the stock lid and snorkel, don't have an open airbox

Update: Worked with Brad at BeRad on a custom set up for my hybrid bike. https://www.berad-products.com/collections/lectron

He was great to work with. The guys over there at Lectron are going to set me up something custom for me. I'll ping back here once I've got it and set it up.