Valve clearances

[kgjersda]

Just checked the valves on my 2000 FZS 600. 57000km. All within spec. Altough Cylinder 1 Exhaust was at minimum. And Cylinder 2 showing some higher numbers on exaust.

Can anyone explain a little bit why C2's exhaust is a lot higher than C1 and C4? Should i check again in ... 15000km instead of next 42000? Is it possible that they would go faster out of spec seeing this? Can C1 Exhaust go below spec soon? What's standard from factory, high or low?

What I'm asking really is how do valves live their small little lives

Code: [Select]


           Cy1        Cy2        Cy3        Cy4
Exhaust  21 | 21    27 | 27    25 | 26    23 | 21
         -------    -------    -------    -------
Intake   15 | 16    13 | 13    13 | 13    14 | 14



[celticdog]

This analogy is how they live their small little lives 

[Fazerider]

I last checked the valve clearances 65,000 miles ago and don't plan to do so again.
The valve seats get deepened as the valve hammers at them gradually closing the gap. At the same time, the cam follower wears opening the gap.
The two processes are very slow and take place at a near-identical rate keeping the gap within spec. At least, that's been my experience for the first 115,000 miles,  after that I tend to fit a new engine as it's easier than changing the camchain and the gearbox is usually pretty baulky by then.

[daviee]

thats a huge mileage you got their 115 thousand miles says alot for the strength of these  units
 

[kgjersda]

Thanks for the responses.

wow, 115k miles! I bet the rust and oxidation will eat away my fazer before that time

[JoeyMcEssex]

Fazerider are you saying don't check them? my Fazer has 44k was thinking of a check just to be sure but if fazer's are so reliable will probably not bother!

[Fazerider]

Fazerider are you saying don't check them? my Fazer has 44k was thinking of a check just to be sure but if fazer's are so reliable will probably not bother!

I checked them religiously on the first engine, but the figures changed only a tiny amount each time and were still in spec when I junked that motor. I checked the clearances on the new one (new to me, actually had 40,000 on it according to the breaker) before putting it in the frame and haven't bothered since as I'm confident enough that they won't drift.
Most others seem to have similar results though a few will change shims as a precaution to get as close to the centre of the range as possible. Your results may differ of course, it's probably better to measure once and be certain rather than trust other people's experiences totally.

[kgjersda]

I measured mostly because I have no history on the bike. No known last service or anything, just the milage.

[Gnasher]

Most are measured incorrectly you want a larger gap not smaller, the shims never wear unless you've used cheap oil, not changed it at the correct intervals or there been an issue with the oil system.


If there within tolerance they're fine.