osteoderm
out of the box
Much improved, although the throttle is still a bit of an On/Off switch below 2000rpm. I have a couple other progressive throttle cable cams to try; that might smooth it out a bit.
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The Lectron Thread
- Thread starter osteoderm
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- carburetors
Much improved, although the throttle is still a bit of an On/Off switch below 2000rpm. I have a couple other progressive throttle cable cams to try; that might smooth it out a bit.
osteoderm
out of the box
I wanted a thread like this to watch myself, so I had to start one
Well said; I completely agree. The carb is really obviously designed to shine when it's opened up and roaring, and it does so very well. However, I do think seamless transition through the complete throttle range is completely available with a metering-rod carb; you'd just have to have the patience to develop a rod grind very specific to your own machine.
This is where Mikuni et al have the advantage; their carbs are more easily tuned to a much wider range of engines, modifications, and conditions. You might say that they are much more "universal" in their application.
Right now I just want to ride and have fun. Down the road, I can see wanting to try different rods (0-1XL? 1-1XL?), but there's no shortage of other areas on the bike that are keeping me busy at the moment...
snatchman
Newbie with lots to learn
Any thoughts on how well a two into one intake would work with the lectron?
osteoderm
out of the box
I don't suppose it's going to be any more involved than any other 2-1 intake swap. Some say that since a 2-1 carb setup is still only supplying fuel/air to one intake stroke at a time, the jetting should be the same as for a 2-2. On the other hand, Lectron recommends richer jetting for 2-stroke applications, where the carb is seeing more intake cycles per revolution. Call Kevin at Lectron, build one up, and report back with your experiences!
I've personally never understood the whole 2-1 intake thing.... It looks tricky to build a decent equal-length intake manifold that doesn't have overly-long runners, doesn't look rough, or flow weirdly. If it's all for style, then anything goes and I'm all for that
, but otherwise I've never understood how any potential advantages could trump all the hassle.However, I'm all about the empirical process, and so is this thread! If you build a 2-1 Lectron setup, please report back and let us know how it works, how you've tuned it, and what works or doesn't work.
tonyc
XS650 Guru
I would build an intake plenum with some sort of injection for starting near th intakes.
Osteo, just for clarification, 2-stroke motors require richer jetting than equivalent 4-strokes for the same reason that they don't yield twice the power of a 4-stroke of equivalent displacement and are harder to clean up to meet emissions standards. 2-strokes don't breathe as efficiently: there's always more fuel being lost out the pipe and more unscavenged exhaust gas left in the charge being burned.
This thread is a great read--thanks!
This thread is a great read--thanks!
osteoderm
out of the box
Thanks for the correction! Lectron does recommend richer baseline jetting for 2-stroke applications, but I was just surmising the reason why; 2-strokes really aren't my thing, and I can't claim any special knowledge there.
You're very welcome. I hope it's helpful to others, and I hope other Lectron users contribute!
650performance
XS650 Addict
On the factory flat track bikes with OU engines that were set up by C.R. Axtell in the '70s they fitted 36mm Lectrons (38mm for mile tracks) and used a 2-3 needle positioned 2.0 turns down. These were obviously fire-breathing competition-only engines and no one cared how they idled.
Since it came up I'll weigh in. I'm running a 40mm Lectron with the single power jet on my self made 2 into 1 intake. I relied on Kevin's ( at Lectron ) advise on the set up. He put it together for me, shipped it, I mounted it and it ran good out of the gate. I passed Arizona emissions test with flying colors after fixing a small intake leak on my 2 into 1. The leak repair really boosted the performance as well. The only thing I can compare it to, is an XS my son had and my previous bike. This bike easily out performs both of them. I'll try to find a place to have it dyno tested. I'm running straight exhaust, Boyer ignition and a Hughes PMA. I had several people say it would never pass emissions. Kevin said they clearly didn't know what they were talking about and he was right. I'm building a rephase with the 750 kit. Still deciding whether to run the twin Lectrons or stick with the 2 into 1. Either way I'm sticking with the Lectron. Spend the extra couple bucks and get the metering rod tool from them.
osteoderm
out of the box
I've put ~400 miles on the bike since my last update here. I briefly (for 50 miles) tried the carbs another 1/4 turn leaner, but that put me into an obviously lean off-idle condition (popping on decel, hanging idle, poor "snap"), so I'm back to 2-turns lean.
I've stopped fighting with the idle. At 2-1/4 turns lean, the idle was easy to set at 1200rpm or so, but everything else suffered. At 2 turns lean, I'm finding stable idle at 1750rpm; this is annoying, but everything else is awesome, so whatever, I can live with it. I'm not discounting that there may be something else at play here besides rod setting and idle slide height, but I'm not going to let it ruin my summer if I can't get a stable burbly 800rpm idle out of the bike.
I've been opening up the power jets in 1/8-turn increments. I'm now at 1/2 turn open, with still no feel of obvious WOT over-richness. As it is, the power gains beyond 1/2 throttle are just silly. Above 3500 rpm, snapping the throttle open rewards with a gnarly bellow, immediate bog-free power, and a split-second delay before a surge of even more power.
I'm guessing that the tiny delay may be because the fuel in the power jet pickup line has to travel a little over an inch to the power tube, and the vacuum drop from a snapped WOT doesn't let the fuel move fast enough. Total conjecture though. I'm going to continue tweaking the power jets open until I feel WOT bog, then fine-tune with some WOT chops and plug checks.
I still have not found the point where the bike looses breath. Things flatten out over 6k rpm, but the bike still pulls all the way to 8k with no fuss. Oh, and I'm still getting at least 50mpg.
I've stopped fighting with the idle. At 2-1/4 turns lean, the idle was easy to set at 1200rpm or so, but everything else suffered. At 2 turns lean, I'm finding stable idle at 1750rpm; this is annoying, but everything else is awesome, so whatever, I can live with it. I'm not discounting that there may be something else at play here besides rod setting and idle slide height, but I'm not going to let it ruin my summer if I can't get a stable burbly 800rpm idle out of the bike.
I've been opening up the power jets in 1/8-turn increments. I'm now at 1/2 turn open, with still no feel of obvious WOT over-richness. As it is, the power gains beyond 1/2 throttle are just silly. Above 3500 rpm, snapping the throttle open rewards with a gnarly bellow, immediate bog-free power, and a split-second delay before a surge of even more power.
I'm guessing that the tiny delay may be because the fuel in the power jet pickup line has to travel a little over an inch to the power tube, and the vacuum drop from a snapped WOT doesn't let the fuel move fast enough. Total conjecture though. I'm going to continue tweaking the power jets open until I feel WOT bog, then fine-tune with some WOT chops and plug checks.
I still have not found the point where the bike looses breath. Things flatten out over 6k rpm, but the bike still pulls all the way to 8k with no fuss. Oh, and I'm still getting at least 50mpg.
'RE: the hanging idle, what freeplay have you got in your cables.?
You seem very thourough so I'm guessing you've read this from electrons faqs.....
My motor runs great but it does not Idle good?
The idle on a Lectron is adjusted with the metering rod. If your motor runs good except idle you will have to first determine weather it is rich or lean causing your poor idle. With engine off look at your slide height. (this is the cut away in the carb slide) If the slide height is high (all most at the end of the adjustment) then the engine is rich. If the slide height is low (all most closed) then the engineis lean. "example motor idles poor or very or low RPM and your slide height is high. You need to lean out rod 1/4 turn reassemble and retest. The RPM should go up and you should have to lower slide. If this is not enough repeat sane step until RPM goes up." You can do the opposite if the engine races or has very low slide height.
I'm sure you'll get it sorted.
Regards.
You seem very thourough so I'm guessing you've read this from electrons faqs.....
My motor runs great but it does not Idle good?
The idle on a Lectron is adjusted with the metering rod. If your motor runs good except idle you will have to first determine weather it is rich or lean causing your poor idle. With engine off look at your slide height. (this is the cut away in the carb slide) If the slide height is high (all most at the end of the adjustment) then the engine is rich. If the slide height is low (all most closed) then the engineis lean. "example motor idles poor or very or low RPM and your slide height is high. You need to lean out rod 1/4 turn reassemble and retest. The RPM should go up and you should have to lower slide. If this is not enough repeat sane step until RPM goes up." You can do the opposite if the engine races or has very low slide height.
I'm sure you'll get it sorted.
Regards.
FLEA
XS650 Guru
what is your bike idle at/is hot or cold making much differnence/what is your rod set up and is it much different to what kevin at lectron suggested? so many questions.could you do a compleate write up? thanks as you are the first to post with a moden lectron conversion(there must be more out there) photos would be nice.(i have a spare 2-1 wiseguy inlet laying around and the added performance would be nice)
If I have the idle real lean (for emmisions) it does run better when its hot , Open up the metering rod a half turn and it idles great. My power jet is set at 1/2 turn. My throttle does hang up a bit and requires a little throttle snap to correct it. Kevin said it could be a result of 2 clyinders creating a little to much draw against the slide. He said if I send him the slide he could correct it. May need a stronger spring? When I get back on Tuesday I may have some better pics. Breaking news though. Arizona just did away with the motorcycle emmision law!
Attachments
Just want to be clear. Bike will idle well apart from the throttle hang. There were 2 different slide springs available for the 40mm. Ihave the stronger of the 2, but still may not be enough. Keven said he could relieve the pressure by drilling some holes in the slide? I had a buddy say he had heard of racers polishing the slide? Outside of the minor throttle hang, it runs great. Im thinking its correctable.
osteoderm
out of the box
When Received my carbs, they were in great shape, rebuilt by Lectron. Still, the slides looked a little manky, and the action wasn't 100% buttery smooth, so I lapped them with 1200grit wet/dry. Not enough to take off significant material, but enough to make them shine. Bike off, the throttle/slide/cable action is outstanding.
Engine running, I can really feel the vacuum at the throttle, and that last little bit of slide return can be elusive at times, even with plenty of slack in the cable(s). I'm thinking of trying stiffer return spring myself, but it's not a priority.
FLEA
XS650 Guru
has there been any more progress on the lectrons???
I sent the carb back to lectron. Keven told me he did every modification he could do to it. Pretty confident they put a stronger slide spring as well. Bottom line it works perfectly. I've ridden it quite a bit and no hanging throttle. Idles very good. A little cold natured, but as soon as it warms up for less than a minute, it takes off like a rocket. I'm very happy with the performance. I'm in the process of building a rephase with a 750 modification. Not sure if I'll run the single or run twins. Either way I'm still leaning toward the Lectron's.
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FLEA
XS650 Guru
thanks for the update,have sent email to keven and waiting reply.what other modifications did he do besides the springs ?? and has it made much difference to your mpg.
Here is what they listed.
1. Top cover gasket, float bowl gasket, fuel screen
2. Split body resurface and reseal
3. Float bowl brace kit
4. 2 vent tubes
5. Machine carb body and slide custom fit and do all slide mods.
6. Shipped back with insurance
7. Not listed on work order. The slide spring was changed, because he sent the old one
back.
The carb was brand new Less than a year ago. He listed that the cost with insurance was $138.40. He didn't want me to pay that. I told him that I didn't expect him to do anything extra for nothing. We settled for $59.45. I'm happy with the result
1. Top cover gasket, float bowl gasket, fuel screen
2. Split body resurface and reseal
3. Float bowl brace kit
4. 2 vent tubes
5. Machine carb body and slide custom fit and do all slide mods.
6. Shipped back with insurance
7. Not listed on work order. The slide spring was changed, because he sent the old one
back.
The carb was brand new Less than a year ago. He listed that the cost with insurance was $138.40. He didn't want me to pay that. I told him that I didn't expect him to do anything extra for nothing. We settled for $59.45. I'm happy with the result
FLEA
XS650 Guru
well, bit the bullet and ordered it,found kevin really helpful,its been built and modified as we speak so now the nail biting wait starts but should have done this months ago as the exchange rate really is starting to hurt now
