A farewell to jets
Posted: 08:54 am Mar 16 2020
I wanted to share my observations and initial impressions from my recent Purchase and install of a Lectron Carburetor. To frame the situation, I have been unable to tune the stock carb for the last few weeks after several jet changes, cleanings, and a metering block gasket it still wanted to run rich or surge and die. This convinced me that the original carb had become worn out and needed a total replacement.
I chose to replace the stock carburetor with a Lectron for specific reasons. The biggest factor is that my riding and wrenching time are one in the same. Jet changes are simple, and I have a working understanding of how to make the changes needed but they take time away from riding. The second reason is environmental. Although I don’t see much elevation change the temperature swings wildly for large portions of the year in northwest PA. This makes it difficult as you can’t simply switch to cold weather jetting.
I placed an order and purchased the full kit with carb, needle adjuster, new cable, and throttle tube. I wasn’t entirely thrilled that they don’t have a phone number on their site. I wouldn’t say this is a “cheap” mod and call me old fashioned, but I prefer a phone call over 10 emails. There is a phone number provided once you place an order or send an inquiry to their sales team. I think this is probably to keep “window shopper” calls from filling their days. I had read enough good reviews that I believed they would send a quality product and moved ahead with the order providing details of engine mods in the order notes. The Lectron arrived at my house 10 days after order with 3-day shipping option so they hit their timeline dead on for completion.
The physical appearance of the Lectron is nice, its almost a polished surface. They also include the aluminum bowl mounting bracket which is nice to see as I know that was an extra option in the past not standard. The right-hand side of the carb has been milled by about 5.5mm. I assume this was a correction to fix fitment issues others have had. There was also a small portion of casting on the cap that was milled down as well. A cap bolt as well as a carb body bolt are relocated to accommodate this. While this work serves its purpose, it is rough machine work and leaves ½ threads from the original carb design exposed. That is purely an aesthetic observation doesn’t seem like it would affect operation in any way. The gasket appears to be installed when the machining is done making it a matched set and any future gasket would need trimmed and drilled for the application. There was some roughness on the flat side of the slide bore but it didn’t seem to be causing any “sticktion” to the slides movement. The throttle slide is nice overall, I was a little discouraged by the cable engagement as it seems like it isn’t distributed over much surface area and could cause wear of the cable end or slide. The top side of the slide has a sharp square edge from machining that seems like it would benefit from some slight chamfer work to reduce the slide bore wear. Needle adjuster mechanism is nice seems to work smoothly. The right-hand choke location sucks plain and simple but what are ya gonna do right. It’s perfectly functional once you get to it. Installing the unit was straightforward the timestamps from my photos indicated that it only took 9mins from no carb at all to a carb installed, leveled, and cable routed to bars. I probably had more time in setting up the new throttle tube and cable than the actual install of the carb. The cable is a little long but came into adjustment well enough using both the inline adjuster and adjuster at the throttle mount. I had the seat, shrouds and tank removed to open the area up so that was more time on the re-assembly. Overall it took about an hour and a half to get it in the bike to the point it was ready to run. Sorry there aren't more photos, the files from my phone are all too large to load.
The first run attempt was hampered by an air leak that sent the bike revving to the moon and rendered the kill switch useless. The stock intake boot clamp does not seem to be able to squeeze the boot enough to seal perfectly. I got a clamp from a 98KX100 that was smaller, and the problem was resolved. I didn’t find the issue until after I got spooked by how lean it had been and adjusted the needle ½ turn richer. I decided to leave the needle richer as added insurance.
Now the carb is installed, and the bike will start and idle nice and smooth in 38F temps this was a big improvement. The Lectron overall is impressive in function. It doesn’t seem to load up the bottom end at all in lower RPMs which is nice to not have to clear out after some slow speed work. The torque and response I would say is on par or slightly better than the stock carb when it had been running correctly. The place this thing shines for me is the middle all the same power is still there it’s just smoother and more predictable. “Linear” is what everyone calls it and that is the best word to describe the power, there are no blips or jumps just one flat predictable line. For me right now that is perfect, I know not everyone wants that. This is still ½ turn rich from how the unit arrived so it’s possible more performance is to be had by going a little leaner. It did seem to sign off a bit early on the top end but I haven’t tried to adjust the power jet to fix this. One of the strangest things is the sound difference. I’m not sure how to describe it other than lower and less sporadic. It sounds rich but is smoking less and running better than before.
Long term it’s yet to be seen if this was a good purchase. I do want to thank members on this site that worked tirelessly with Lectron on developing a carburetor that fit easily. I know you probably didn’t benefit much from it but it is appreciated. I also want to add that this is not an endorsement of Lectron over say an RB carb. I haven’t had the chance to run one of those. The only reason I didn’t go with one of those is that I don’t see myself having time for swapping jets regularly any time soon. I won’t say it’s the best carb ever but it is the best one for me personally.
I chose to replace the stock carburetor with a Lectron for specific reasons. The biggest factor is that my riding and wrenching time are one in the same. Jet changes are simple, and I have a working understanding of how to make the changes needed but they take time away from riding. The second reason is environmental. Although I don’t see much elevation change the temperature swings wildly for large portions of the year in northwest PA. This makes it difficult as you can’t simply switch to cold weather jetting.
I placed an order and purchased the full kit with carb, needle adjuster, new cable, and throttle tube. I wasn’t entirely thrilled that they don’t have a phone number on their site. I wouldn’t say this is a “cheap” mod and call me old fashioned, but I prefer a phone call over 10 emails. There is a phone number provided once you place an order or send an inquiry to their sales team. I think this is probably to keep “window shopper” calls from filling their days. I had read enough good reviews that I believed they would send a quality product and moved ahead with the order providing details of engine mods in the order notes. The Lectron arrived at my house 10 days after order with 3-day shipping option so they hit their timeline dead on for completion.
The physical appearance of the Lectron is nice, its almost a polished surface. They also include the aluminum bowl mounting bracket which is nice to see as I know that was an extra option in the past not standard. The right-hand side of the carb has been milled by about 5.5mm. I assume this was a correction to fix fitment issues others have had. There was also a small portion of casting on the cap that was milled down as well. A cap bolt as well as a carb body bolt are relocated to accommodate this. While this work serves its purpose, it is rough machine work and leaves ½ threads from the original carb design exposed. That is purely an aesthetic observation doesn’t seem like it would affect operation in any way. The gasket appears to be installed when the machining is done making it a matched set and any future gasket would need trimmed and drilled for the application. There was some roughness on the flat side of the slide bore but it didn’t seem to be causing any “sticktion” to the slides movement. The throttle slide is nice overall, I was a little discouraged by the cable engagement as it seems like it isn’t distributed over much surface area and could cause wear of the cable end or slide. The top side of the slide has a sharp square edge from machining that seems like it would benefit from some slight chamfer work to reduce the slide bore wear. Needle adjuster mechanism is nice seems to work smoothly. The right-hand choke location sucks plain and simple but what are ya gonna do right. It’s perfectly functional once you get to it. Installing the unit was straightforward the timestamps from my photos indicated that it only took 9mins from no carb at all to a carb installed, leveled, and cable routed to bars. I probably had more time in setting up the new throttle tube and cable than the actual install of the carb. The cable is a little long but came into adjustment well enough using both the inline adjuster and adjuster at the throttle mount. I had the seat, shrouds and tank removed to open the area up so that was more time on the re-assembly. Overall it took about an hour and a half to get it in the bike to the point it was ready to run. Sorry there aren't more photos, the files from my phone are all too large to load.
The first run attempt was hampered by an air leak that sent the bike revving to the moon and rendered the kill switch useless. The stock intake boot clamp does not seem to be able to squeeze the boot enough to seal perfectly. I got a clamp from a 98KX100 that was smaller, and the problem was resolved. I didn’t find the issue until after I got spooked by how lean it had been and adjusted the needle ½ turn richer. I decided to leave the needle richer as added insurance.
Now the carb is installed, and the bike will start and idle nice and smooth in 38F temps this was a big improvement. The Lectron overall is impressive in function. It doesn’t seem to load up the bottom end at all in lower RPMs which is nice to not have to clear out after some slow speed work. The torque and response I would say is on par or slightly better than the stock carb when it had been running correctly. The place this thing shines for me is the middle all the same power is still there it’s just smoother and more predictable. “Linear” is what everyone calls it and that is the best word to describe the power, there are no blips or jumps just one flat predictable line. For me right now that is perfect, I know not everyone wants that. This is still ½ turn rich from how the unit arrived so it’s possible more performance is to be had by going a little leaner. It did seem to sign off a bit early on the top end but I haven’t tried to adjust the power jet to fix this. One of the strangest things is the sound difference. I’m not sure how to describe it other than lower and less sporadic. It sounds rich but is smoking less and running better than before.
Long term it’s yet to be seen if this was a good purchase. I do want to thank members on this site that worked tirelessly with Lectron on developing a carburetor that fit easily. I know you probably didn’t benefit much from it but it is appreciated. I also want to add that this is not an endorsement of Lectron over say an RB carb. I haven’t had the chance to run one of those. The only reason I didn’t go with one of those is that I don’t see myself having time for swapping jets regularly any time soon. I won’t say it’s the best carb ever but it is the best one for me personally.