BannedCR500Riders.com

Hi guys! I have been recommended by a tuner here in Sweden to swap my PWK 41,5mm for a lectron 44mm. My bike has just been ported 3,5mm exh. 1,5mm trans, ported intake, coolhead, Power reeds, ProCircuit system. Does anyone have any exdperience of comparing those carbs? What,s the difference/improvement? Is it worth it?

Johnny

Lectrons are great for WOT racing, suck for everything else...

Slomo wrote:Lectrons are great for WOT racing, suck for everything else...

X491

Ok, so what,s the problem with part throttle? Is it just the whole layout of the carb? I was thinking of one for the 500, but maybe it,s not a good idea for roaduse?

Johnny

johnnytheswede wrote:Ok, so what,s the problem with part throttle? Is it just the whole layout of the carb? I was thinking of one for the 500, but maybe it,s not a good idea for roaduse?

Johnny

Either live with a gurgle fat off idle or a smokin lean mid range. Like they said, the big end tis good.

If you think you can tune it out, I have a bunch of needles I will sell you. They are like $35 each from Power Addiction www.poweraddictionracing.com

4Z wrote:

johnnytheswede wrote:Ok, so what,s the problem with part throttle? Is it just the whole layout of the carb? I was thinking of one for the 500, but maybe it,s not a good idea for roaduse?

Johnny

Either live with a gurgle fat off idle or a smokin lean mid range. Like they said, the big end tis good.

If you think you can tune it out, I have a bunch of needles I will sell you. They are like $35 each from Power Addiction www.poweraddictionracing.com

Ok. Thanks for the info! I will think about it.

Johnny

I'm a little surprised to hear this comment about Lectron carbs. I admit, I have never put one on a CR500, but I've run them on lots of older vintage bikes and they all ran perfect, no blubber, no lean mid-range.

PWK is the only way to go on a 500. I ran mikuni on my gen-1 and when I had it running good it ran really good, but it was very tempermental and required a lot of tuning all the time. My friend is running a lectron on his rhino and its a PITA to tune, the thing never starts right and part throttle sucks, but WFO is awesome.
If you are building a bike that is only going WFO, like a bike for sand drags, I'd say go for it, but the rest of the time a 41mm PWK with a powerjet can't be beat.
I'd say save your money and keep the pwk.

Also, the airboot needs to be opened up just for a 41mm, You'd have to build a custom intake to even take advantage of the 44mm.

I have four bikes with Lectron carbs, all older Vintage air cooled big bore two strokes, Penton/KTM 400s, Maico 440s, etc. They all start 1st kick and they all run flawlessly, almost like fuel injection. As I said, I have zero experience with a Lectron carb on a CR500, but I fail to see why it could not be tuned to run perfectly. As to them being a PITA to tune, that is complete BS, there are only two parts to tune, the powerjet and the needle, and the needle is super easy to adjust. Yes, it CAN be a PITA to find the correct needle for some bikes, but once you find it you never have to touch it again.

problem with lectron on these bikes is they dont fit in the frame unless you cram a 44 in the stock boot but i cant see that being a very good fit considering the boot was made for keihin. tried on mine with vf3 and it does not fit. now the aluminum frames are a different story. no backbone to get in the way.

dannygraves wrote:PWK is the only way to go on a 500. I ran mikuni on my gen-1 and when I had it running good it ran really good, but it was very tempermental and required a lot of tuning all the time. My friend is running a lectron on his rhino and its a PITA to tune, the thing never starts right and part throttle sucks, but WFO is awesome.
If you are building a bike that is only going WFO, like a bike for sand drags, I'd say go for it, but the rest of the time a 41mm PWK with a powerjet can't be beat.
I'd say save your money and keep the pwk.

Also, the airboot needs to be opened up just for a 41mm, You'd have to build a custom intake to even take advantage of the 44mm.

Hello DannyGraves. So, i already have a PWK 41,5mm and my bike is running good with it, except a slight hesitation at very light throttle that i can,t get rid of. Is it easy to install a powerjet? How do i do that, and what are the benefits with it? What parts is required? if i decide to do it?

Johnny

The advantage is the ability to run a leaner main which will give you better response when you snap it all the way open and that the jet is essentially vacuum powered so if you are still making power, it will continue adding fuel. The hesitation you are experiencing is either the pilot of the needle, what is your jetting set at and what needle are you running?
there are 2 types of powerjets, the mikuni ones where you have to swap out jets and there are a handful of adjustable ones. I'd go with the adjustable ones. To install, you remove the overflow rod from the floatbolw, hook a tube to the bottom of the bowl and drill a whole to place the powerjet in on the carb between the slide and airbox.

the ones that 4Z linked are excellent

dannygraves wrote:The advantage is the ability to run a leaner main which will give you better response when you snap it all the way open and that the jet is essentially vacuum powered so if you are still making power, it will continue adding fuel. The hesitation you are experiencing is either the pilot of the needle, what is your jetting set at and what needle are you running?
there are 2 types of powerjets, the mikuni ones where you have to swap out jets and there are a handful of adjustable ones. I'd go with the adjustable ones. To install, you remove the overflow rod from the floatbolw, hook a tube to the bottom of the bowl and drill a whole to place the powerjet in on the carb between the slide and airbox.

Ok, then i understand. I have tried all kinds of jetting and slides, but the feeling of slight hesitation at 1/8 throttle is still there, even if i jet it rich at the bottom, so i was thinking that it could be my lighting system the t robbed power from the ignition sysytem. I have removed all my lights now for the iceracing season, but i can still feel this lean feeling hesitation. It,s very obvious at street driving because i use so light throttle. The bike starts very easy and runs very good everywhere else in the powerband. I have a PWK 41,5mm btw=). JD blue needle in 4th, 180 main and 55 pilot, 6 slide. 187 degrees exh. 125 degrees trans.

Johnny

drop your pilot down to like a 45 or 48 and tell me if that clears it up. It sounds like you are running fat on the pilot and blubbering until the needle takes over.

He never said what the number or letters of the needle are.
Me thinks the last letter or the last two numbers of the needle need to change.

Also anytime I see someone wanting to change the carb is telling me there having trouble jetting what they have. Please don't take that personal Johnny. Helping people is what were here for.

And for the record I'm still running the PJ. and with the denser air over TG weekend I got srugging while the throttle was closed slowing down in 3,4,5 gear.

Yeah, I don't know anything about that JD needle, buy some keihin needles.

Well, i,m quite familiar with jetting and i know how to jet a lean running, but it doesn,t work. i tried different slides, DGL,DGK,DGN, CGJ,CGL needles in different positions, different pilots bla bla bla, but it won,t go away, so i suspect it has something to do with ignition. I had a BR 85EGV plug in it earlier, but i changed that to a BR 8EG standard plug and that was better. I,m thinking of going for a 7 plug to see how it behaves. I suspected that the coolhead made it running cooler and therefore made the plug misignite. What do you guys think? Is it a risk to run with a 7 plug with a ported 500?

Johnny

a loose coil ground bolt can cause all sorts of problems at certain rpms, yet fire up and idle perfectly and never stall out?????
changed out a lot of brass trying to fix that one

2strokeforever wrote:a loose coil ground bolt can cause all sorts of problems at certain rpms, yet fire up and idle perfectly and never stall out?????
changed out a lot of brass trying to fix that one

yes, I have a bad coil that I didn't notice until it was running at night in front of my house and I could see it arching all over the place. Swapped the coil and it ran perfectly.

Ok, that was a good tip! I,ll check the earth connection and see if that helps! Thanks so far guys! i,ll get back when i have tried it. It,s almost zero outside and i have slicks on it now...

The 7 shouldn't hurt anything.

Someone here had an issue , maybe similar. There was no clamp on the wires coming out of the mag and the ground wire melt through rubbing the pipe. We were just sitting eating lunch at camp and I spoted it.

you would only want to drop down to a 7 if you were fouling plugs.

dannygraves wrote:you would only want to drop down to a 7 if you were fouling plugs.

Yes, i guess that,s the common reason, but i also read that Eric Gorr recommended to change to a nr6 plug for the 500. I wonder what the reason for this is as it,s working ok with the standard nr8?

Johnny

only if you have done the other modifications he suggests too.
Remember his head mods are based on an ML3-R casting, not the HF, HF-1, ml3 or ml3-N heads