Valve Adjustment Intervals

[MCRIDER007]

As a C14 owner, I follow some of the technical discussions on the C14 forums, and one of the popular topics is the 15k valve check/adjustment interval for US and Canada models vs 26K intervals for the C14s in the rest of the world. The only differences are that the US and Canada models have an open loop FI system; the rest of the world gets a extra CAT, an O2 sensor, and a closed loop FI system. Kawasaki has given an official explanation for the different intervals to the magazine published by the Concours Owners group but no one is sharing that exact document. A couple of members have hinted that Kawasaki has to certify to EPA that their engines will stay in full compliance with EPA emissions requirements for a specified valve adjustment interval and Kawasaki has chosen to go with the shorter interval for the US and Canada models. I have always thought that the valve adjustment interval's primary purpose was to prevent engine damage, especially a burned exhaust valve, although I have noticed that the clearance specs for today's water cooled under the bucket shim adjustment engines are larger than what I remember for yesterday's air cooled thread and lock nut engines (which had to be adjusted every 3-6K miles). Burned valves were not that uncommon on the air cooled engines but I have never heard of a burned valve on a water cooled shim under the bucket engine...and when the valves are out of "spec", it usually by a very small amount. One never knows what you are going to find on that first valve adjustment but the clearances don't seem to change much after that (unless you are in the mega miles club).

Does anyone have any solid knowledge on this issue? Is the primary purpose of a valve adjustment interval to prevent engine damage or a conservative estimate of what it takes to keep the engine in strict compliance with EPA requirements?

 

[Constant Mesh]

Probably emissions control. The valve clearance check/adjust is included in the "Periodic Maintenance Chart for the Emission Control System".

Many other engine maintenance guidelines are included in the "General Maintenance and Lubrication Chart".

 

[bigtallguy]

I remember the manual for my zx-14 saying 15k miles/26k kilometers. There was some confusion at one time because some people were thinking the 26k was miles and wondering why everyone was checking their valves so soon.

Most didn't have to change any shims on the first check though, I was not as lucky, tried to do it myself, then bent all the valves :angry2: It's time to check the clearances on the FJR now... :huh:

 

[MCRIDER007]

I remember the manual for my zx-14 saying 15k miles/26k kilometers. There was some confusion at one time because some people were thinking the 26k was miles and wondering why everyone was checking their valves so soon.

The ZX-14 and the C14 share the same confusion about the valve adjustment intervals. The US and Canada ZX-14s have a 15K miles interval, the rest of the world ZX-14s have a 26K miles interval.

 

[RadioHowie]

The ZX-14 and the C14 share the same confusion about the valve adjustment intervals. The US and Canada ZX-14s have a 15K miles interval, the rest of the world ZX-14s have a 26K miles interval.

Are you SURE it's not a 15K Miles vs. 26K Kilometers?

'cause it's the same thing, and "the rest of the world...." DOES use the metric system (although so does Canuka).

 

[MCRIDER007]

The ZX-14 and the C14 share the same confusion about the valve adjustment intervals. The US and Canada ZX-14s have a 15K miles interval, the rest of the world ZX-14s have a 26K miles interval.

Are you SURE it's not a 15K Miles vs. 26K Kilometers?

'cause it's the same thing, and "the rest of the world...." DOES use the metric system (although so does Canuka).

If you want to talk in Kilometers, the valve interval in the US and Canada is 24k Kilometers, the rest of the world is 42K Kilometers.

 

[RadioHowie]

If you want to talk in Kilometers, the valve interval in the US and Canada is 24k Kilometers, the rest of the world is 42K Kilometers.

In that case, the difference between the North America valve check versus the rest of the world makes no sense at all.

 

[OldSwartout]

In that case, the difference between the North America valve check versus the rest of the world makes no sense at all.

The change in valve opening time will vary slightly with a change in clearance. It could affect emissions, then depending on how close the engine is to the local emission limits, the statistical probability of exceeding the limits may be different between the US and Europe, affecting how long you have before checking the clearances. Seems pretty far-fetched to me, but...

 

[Conrocks]

:huh: Thought I was on a FJR Forum didn't know it was a Kawii forum. Sorry.