osteoderm
out of the box
Tons of carbs available to fit these bikes; Keihin, Mikuni (BS, VM, and I think there's a few folks on this thread running TM's), Dell'Orto, and Lectron. There's probably others, but this thread is for the Lectron folks. Likewise, I hope this thread won't descend into an endless pro/con debate over these carbs. They're not for every rider, every build, or every budget, but for those of us running them, or those of you who would like to try, I hope this thread can become a resource to refer to.
Loads of decent BS and VM tuning advice on this forum, but the Lectron info feels pretty thin. Just this thread and this thread and this thread here that I've found. Hugh talks about his Lectron setup in this interview. Also some interesting commentary here.
I'm not going explain the Lectron carb right here in this thread. If you haven't already, read this page and this page first.
The basic set-up for the XS650 seems to be Lectron 34mm carbs, long Shell-style intake runners, single adjustable powerjets, and nonrestrictive filtration (ie., large foam UNI's, not short K&N knockoffs). The only real variables are metering rod choice and rod tuning.
Hugh Owings (who I hope will join this thread) has variously described using FBG-1XL rods, 0-1XL rods, and 0-2XL rods (on his bumped-compression 707cc rephase). Kevin from Lectron recommended 0-2XL rods for my own bike (fairly stock, details to follow).
There's an almost infinite number of metering rod grinds, but since each one covers a range of approximately 10 conventional main jets in a Mikuni, in theory you only have to get in the ballpark to get started. Without a bunch of dyno work or other controlled testing, every other rod choice is conjecture.
As for tuning, there's a couple numbers floating around the interwebs. The current Lectron tuning guide, straight off their website, suggests setting the metering rod length at 2.040", as measured from the bottom of the threaded brass rod insert to the tip of the metering rod. Note that this is only a suggested starting point for 4-stroke applications!
Lectron sells a Fuel Ratio Tool which allows for much greater accuracy in setting the correct starting metering rod height, and despite the expense, it seems like a simple way to avoid a ton of fiddling and frustration if you plan to change rods or reset to a baseline often.
If you're running or have run these carbs, please share your tuning, along with general engine build/mods that might apply. Also please leave your general impressions, experiences, and suggestions for what has and has not worked out for you!
Loads of decent BS and VM tuning advice on this forum, but the Lectron info feels pretty thin. Just this thread and this thread and this thread here that I've found. Hugh talks about his Lectron setup in this interview. Also some interesting commentary here.
I'm not going explain the Lectron carb right here in this thread. If you haven't already, read this page and this page first.
The basic set-up for the XS650 seems to be Lectron 34mm carbs, long Shell-style intake runners, single adjustable powerjets, and nonrestrictive filtration (ie., large foam UNI's, not short K&N knockoffs). The only real variables are metering rod choice and rod tuning.
Hugh Owings (who I hope will join this thread) has variously described using FBG-1XL rods, 0-1XL rods, and 0-2XL rods (on his bumped-compression 707cc rephase). Kevin from Lectron recommended 0-2XL rods for my own bike (fairly stock, details to follow).
There's an almost infinite number of metering rod grinds, but since each one covers a range of approximately 10 conventional main jets in a Mikuni, in theory you only have to get in the ballpark to get started. Without a bunch of dyno work or other controlled testing, every other rod choice is conjecture.
As for tuning, there's a couple numbers floating around the interwebs. The current Lectron tuning guide, straight off their website, suggests setting the metering rod length at 2.040", as measured from the bottom of the threaded brass rod insert to the tip of the metering rod. Note that this is only a suggested starting point for 4-stroke applications!
Lectron sells a Fuel Ratio Tool which allows for much greater accuracy in setting the correct starting metering rod height, and despite the expense, it seems like a simple way to avoid a ton of fiddling and frustration if you plan to change rods or reset to a baseline often.
If you're running or have run these carbs, please share your tuning, along with general engine build/mods that might apply. Also please leave your general impressions, experiences, and suggestions for what has and has not worked out for you!