ASK THE MXPERTS: 2020 CRF450 COMPRESSION RELEASE BREAKAGE

Just like in 2009, MXA broke the auto compression release weight off the 2020 CRF450 pin. we don’t expect this to be a problem on the all-new 2021 CRF450 engine

Dear MXperts,
I have a 2020 CRF450L (my first dual-sport after a life of MX bikes) and am concerned that MXA broke its 2020 CRF450R auto compression release that my L-model could experience the same problem. Should I be concerned about an auto compression release failure?

Based on our past experiences in 2009 and 2017 and now 2020 CRF auto compression relief failures, we don’t think that there is much that you can do about. After the 2009 failures, Honda redesigned the decompression parts, and we are pretty sure that new part is what activates the decompression system on the 2020 models. Essentially, when that part breaks, you lose the use of the automatic compression release for starting (also the broken-off weight will clatter around in the head).

At this time, there are no updated parts available (at least none that Honda is sharing with us), and Honda claims that our breakage issue was the first they have suffered in years, but that is what motorcycle manufacturers always tell us. There were compression release failures at the 2017 Honda press intro on three CRF450s. Honda denied that those failures were due to the auto-compression release system; however, having lived through the 2009 failures, we are pretty sure that they were. You just have to be cognizant of any strange noises when starting your bike. If you hear any odd sounds, shut it down. That’s not much of a solution, but since every CRF450 uses the same decompression system, if it is a real problem, it will show up in numbers eventually.

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