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Xjowners > Tech Talk > Valve adjustment



Title: Valve adjustment


jdrich48 - November 27, 2005 01:58 PM (GMT)
I just finished the build on my carbs, and am waiting for my sync tools to arrive. So while waiting I checked the valves yesterday.
Intake-spec (.004-.006)
#1- .005
#2- .004
#3- .006
#4- .002
Exhaust-spec (.006-.008)
#1- .007
#2- .008
#3- .008
#4- .007
I work on diesel engines all the time and and always try to set valves to the mid range point. But I've never done any work on a bike but assume it should be the same way. I know that #4 intake must be adjusted. How crucial is it that I make adjustments to some of the others that are not right at the midrange point. I assume it would be fine but with the carb sync so crucial, would'nt I get more even readings when I adjust carbs if the valves were all right on?
Also does anyone know were to get the shims I need?
Any feedback would be appreciated.
Is there a shim chart anywhere that has been converted to standard measure?
Thanks
Richard B.


Hillsy - November 28, 2005 12:46 AM (GMT)
I think it's best to shim towards the larger side of the spec'd tolerances for 2 reasons:

The gap will close up (slightly) when the engine is hot, and
The gap will close over time as the valve face / valve seat wear into each other.

At least this way you know you won't be doing any damage to your valvetrain components by having a valve close up on you.

As far as synching the carbs go, 1 or 2 thou difference between the valves should not affect this. If the valves weren't seating properly, this would be an issue (too small a tolerance, burnt valve, etc)

As for shim availability and shim chart, I haven't had to change any of mine as yet so I don't know about anywhere else other than Mr Yamaha.

winterhawk - November 28, 2005 07:12 AM (GMT)
Make sure you check the adjustment when it is stone cold. There is a number on the bottom of the pad. Usually you can go 1 size larger or smaller to get it in specs without having to use the chart.

Your #4 if it is at .002 will probablly take 1 number smaller shim. Install the number face down so it won't get rubbed off by the cams.

mr.fork - November 29, 2005 05:08 AM (GMT)
If you order the XJCD, it'll actually have a chart to measure against. Where those clearances? Your number #4 looks worn. The XJ Mailing list actually has a valve shim pool going. For a $15 depost, you ask for your size, they'll mail it to you, you mail your old one in, then they give you your money back.

jdrich48 - November 29, 2005 05:52 AM (GMT)
Thanks for all the good advice. I'll check into that pool. Already have the cd must have over looked it.




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