Smart Carb vs Lectron vs RB-Designs Mod

[AZRickD]

A non-riding vacation next week gives me a window of opportunity.

I can either send my 2011 250's AS2 carb to Ron for his RB carb mod for $167, or to go with APT Smart Carb (cast version) for $375,
or the Lectron $315 (me thinks).

Which way would you go iffin you were me?

I have had RB mods on both my KDX220 and my '05 DE250 with fine results.

Also, RB's mod has a bore increase from 38 to 39. My riding style dictates that I won't use any more top end, as I prefer more bottom. I'm actually thinking of adding the reed spacer from my other bike (and removing the boot spacer thingy to make room, if need be).

 

[Jakobi]

I can't comment on Rons work, but between the two other carbs and what you've said I'd probably go for a 36mm model which will give you a more useful power curve for trail work.

Between the Lectron and Smart Carb.. its a tough choice. Personally, if going the SC route I'd at least hold off until the 3rd generation are developed and released.

 

[swazi_matt]

Cannot comment on the rb mod but would be more inclined to go with one of the other two purely from the point that you can carry it over to your next bike when you sell, like a steering damper

 

[roverhybrids]

I would wait on the SC.
I have the RB carb on my 300

 

[AZRickD]

I have been reasonably happy with the RB mod on my '05. Not earth shaking like the head mod but it cleaned things up a bit and made me the Dead -Engine Start King.

Is this new release the "3rd Gen" or is the Gen2 in the cast version?

What other problems does he ned to address? Cable? Off-Idle? Metering Rod?

When folks say they are 90% happy with the APT SCarb, is it because they have raised the bar so high? Were they only 80% happy with the RB modded carb? Is the Lectron getting sorted out ?

 

[singletracker]

I don't have experience with SC or the RB mod, but I am happy with the Lectron. It's easy to make adjustments and I haven't had to fuss with it at all after installing it. I've never touched the floats or had any other issues. I did have to modify my stock throttle cable to get it to work, but I recently replaced it with one of Lectron's custom cables. The custom cable fit and works flawlessly. My bike runs better at every throttle position than it did with the stock carb, and it is very smooth.

I can't say what would be better for you, but it seems like many of the SC guys have been fussing over this and that quite a bit. Although the SC is supposed to be more technically advanced, I beleive the Lectron is much more sorted out. I really can't imagine the SC working any better than my Lectron is for my riding and location.

 

[n_green]

What exactly is involved in a RB modded carb?

If you want bottom end and a modded carb I have my oval bored 36 x 39mm AS2 carb i'd happily swap for a 38mm?

Finally got the jetting in my bike close to perfect using Jakes 38mm carb and I'm really happy with the power. Not looking forward to going back and re-jetting my oval bore when Jake wants his 38mm back.

 

[Jakobi]

Maybe its just that fresh top end at work Nath.. and you're oval bore will take it to another level..

IMO the stock AS2 is very good. I didn't see the need to do anything to it other than spend time jetting it. Once its set a turn on the air screw, a half a clip pos here or there, and maybe a quick main change when seasons change is all it took.

The Lectron was very good too. Very quick to get mostly sorted.

The Smart Carb has provided decent results too, however I've had a few niggling issues to work through with it as well. That may just be me, my particular bike, or my smart carb too.

 

[AZRickD]

If I were to jump, I'd go with the Lectron. The combo of metering rod and Power Jet makes sense to me.

However, buying a carb that requires me to buy a longer throttle cable is annoying.

 

[singletracker]

If I were to jump, I'd go with the Lectron. The combo of metering rod and Power Jet makes sense to me.

However, buying a carb that requires me to buy a longer throttle cable is annoying.

I can see your point about the throttle cable, but if you go into it understanding that is an additional upfront cost then it is just a matter of money. The stock cable can be made to work, but Lectron's cable is better.

My bike is running great with the Lectron. I'm running a leaner setting than previously, and I couldn't be happier with it. I'm also noticing better fuel mileage now, but I haven't raced it at the current settings.

 

[AZRickD]

Then there is the cost of the longer choke cable (because the choke is on the wrong side). MotoSportz tells me that he also has a longer remote choke (I like mine on the GG). I don't know if it is a direct bolt-on to the AJP clutch mount or if I will have yet another doo-dad on or near my bars.

I exchanged emails with Lectron about MotoSportz fine-adjustable metering rod and shorter power jet probe. Lectron said the rod works fine. I am not sure if his comment was also intended to praise the shorter power jet as well.

 

[StuJohnson]

Then there is the cost of the longer choke cable (because the choke is on the wrong side). MotoSportz tells me that he also has a longer remote choke (I like mine on the GG). I don't know if it is a direct bolt-on to the AJP clutch mount or if I will have yet another doo-dad on or near my bars.

I exchanged emails with Lectron about MotoSportz fine-adjustable metering rod and shorter power jet probe. Lectron said the rod works fine. I am not sure if his comment was also intended to praise the shorter power jet as well.

Honestly the choke on other side is no big deal....
"If" needed...pull it and kick once. Warm up and then push down.

Not worth t he extra work and money to move it...IMO

 

[AZRickD]

I like mine for on-the-fly enrichment when racing down lonnnng sand washes.

 

[Jakobi]

Yeah no real need for the choke.

Dave did some testing with Kellys MS3 needle (and PJ i think), and said it made the bike run very similar to a Keihin again. Bit flat through the middle compared to the 3-1, which was also reflected on the dyno with the MS3 being down about 8% through the mid range in comparison. I think this was done on his modified TE250 (or CR250). I'd have to confirm which bike. It may or may not be the same on the gassers.

 

[AZRickD]

Hmmmmm. So go with the Lectron rods for now?

Kelly seems to think that the longer stock power jet nozzle makes the Lectron a little rich in the mid (iirc).

 

[Jakobi]

on his husky 165.. correct

You could probably try his PJ (or shorten the stock one yourself), if you weren't happy with the stock config. The length of the PJ just determines when the jet starts to pull fuel.. Shorter being later in the rev range.

I found the 3-1 ran pretty well almost everywhere. The only gripe I had was that it felt like it needed a finer level of adjustment. 1 was slightly rich off the bottom with a strong mid to top, and the next adjustment leaner was a clean as a whistle off the bottom, but ran a touch lean just before it came on song.

 

[AZRickD]

And the power jet adjustment wouldn't fill in the mid without dumping a bit too much on top, eh?

 

[troffer88]

I run the Ms-3 with the longer pj tube , it is to lean in the midrange for my liking with the short pj tube

 

[StuJohnson]

I run the Ms-3 with the longer pj tube , it is to lean in the midrange for my liking with the short pj tube

Tim - Thanks for the post.

All - This is a great person to ask about the Lectron on his GG.

 

[StuJohnson]

I like mine for on-the-fly enrichment when racing down lonnnng sand washes.

Hmmmm..... That is interesting concept.

Never done that before.... But riding the Cascade Mtns in WA state that would not be needed. I just want a carb I can ride from Sea Level - 7000ft and not have to touch it - except for maybe the idle adjustment = Lectron