Updated Valve Clearance Specifications for 2018 (and earlier models)

[fostytou]

While preparing for my valve job I was reviewing the older and newer manuals and some threads and noticed that KTM has updated the valve clearance specifications in the 2018 Duke manual. After some research I've established some facts:

1. The Duke uses our same engine part # motor / head
2. Some of the older manuals have other inaccuracies in them. KTM also seems to update specifications and parts without notice / without updating part numbers
3. A member on another forum has written KTM who confirmed that either specification can be used *on the Duke* including for older models. (I'm not sure if inter forum linking is allowed - if it is please let me know and I will post a link to the other forum's thread).

The old values were:
Intake: 0.08-0.12mm
Exhaust: 0.13-0.17mm


The new values are:
Intake: 0.10-0.15mm
Exhaust: 0.15-0.20mm

We began to discuss it in this thread: https://www.rc390-forum.com/threads...e-parts-and-tools-rc-390-2017.2796/post-32135

The new values are more in line with other bikes that I have worked on. They may actually provide slightly less power by opening the valves less if you are looser in measurement, but there should be less concern about burning up a valve if you miss an adjustment window. As the old saying goes: tappy valves are happy valves. I interpret KTM's communication to mean that the full wider range is acceptable, but of course this may be a misinterpretation. EG: Intake: 0.08-0.15mm should realistically be OK if you are checking them as scheduled.

 

[fostytou]

The 2018 RC 390 manual also gives the new specifications.
Here is the information from pg 233 of the RC390 owners manual I have:


And from page 269 of the 2018 Duke service manual: