I contacted Kehien (and KTM) when I was having trouble with my 2012 KTM 500 XC-W, with excessive leanness and terrible throttle linearity.
They gave me a wealth of information, which took a few months to get clarified and distilled down to some usable information.
I have since learned that the ECU used on one version of the Kehien Throttle Body (the one used on KTM MX, the new WR, and the new 2011/12 CRF450R) is the same on all bikes, electronically. Just the mapping and physical shape are different, and some are LOCKED OUT, like the WR, the EXC's and the TE Husky's. You have to 'unlock' them, or replace them with a 'competition' version, like on the WR, if you want the bike to start, idle, go fast, not stall, and not over heat. Minor, issues, eh?
adjust' feature on the ECU is on all ECU's, but is not necessarily 'active' on all ECU's (Honda CRF450R for example).
It is there to allow 'instant jetting adjustment' by the rider (but only =/- 10% maximum).
You have to do it with a warm motor; one minute of staring and idling with NO throttle, shut off, and then re start and go.
It will also adjust the igniton mapping, but only =/- 1 or 2%, I am told.
Some of the information I gathered from KTM and Kehien was extremely conflicting, even within the same company, so it got very frustrating trying to 'nail down' the exact issues, solutions, and methods.
If the FI system were a closed-loop type system, it would also adjust for more severe issues (clogged injector, extremely high humidity) and do it on the fly, but we don't have that level of sophistication on off-road bikes yet.
Oh, and what happened to the KTM? Well, three over-heated throttle bodies later, I sold it.
The 2012 models have TONS of TB problems, especially the 500, which ran too hot to solve the problems permanently......
Edited by Krannie, March 22, 2013 - 01:28 PM.