Valve adjustments

[CarlMember]

I’m about to adjust my valves on my 600 and I seem to be having a slight issue. I have read a few documents online and in the manual and have read about the “true tdc” to adjust valves from. The problem is if I use the kick start I can never seem to get the “T” mark perfect. It is always just before and if I move the kick a little more it goes just past. I put her up on a bike stand and have put it in gear and I can make fine adjustments to the crank possition using the rear wheel. Is this ok to do it that way?
Also I’m finding it extremely hard to actually read the gap space as the feeler gauge is rubbing and grabbing on the valve cover hole. Do you usually just adjust the valve clearance so it binds tightly on the feeler gauge then just adjust back until you can slide it slightly or will this still be too tight?
And as for the decomp lever interfering with the right exhaust adjustmet can I just remove the cable to ensure it isn’t interfering or will that still make an issue? As it is set up now there is about a 8mm free play at the motor end. Is this ok for valve adjustments?
Thanks in advance for the help

[Mick DMember]

Syco, what I used to do with my 600 was use a 17mm socket and a ratchet on the end of the crank to get the fine adjustment required to line up the T mark.

What you are doing with the feeler guages sounds ok as long as there is a little bit of resistance when you move the feeler gauge,you should be right.
It is the Auto decomp that causes the issue with it binding on the RH exhaust valve not the manual one.
When the decomp used to bind up on the right hand exhaust valve, I would use the kicker to turn over the motor a full revolution, line the T mark up again and it should be good. Another trick I have used is to use the ratchet on the crank and turn the motor back wards (anti clockwise) just a tad,you should hear an audible click as the decomp dissengages.Once it clicks, line up the T again by turning the motor back the other way (clockwise). I have heard that it is not a good idea to turn your motor backwards but it does work and the motor never seemed to suffer from doing that.

Are you talking 8mm free play on the lever that the decomp cable connects to on the rocker cover?

[CarlMember]

Thanks for the responce Mick. Yeah the free play is at the rocker. The free play is actually on the decomp and not the cable, when you move it over the first 8mm there is no resistance then it kicks in. I assume that is right as it is the way I got it and the decomp lever works fine.
I did adjust attempt to adjust the valves a fortnight ago and I seemed to go ok but over the last couple of days she has started to sound a little rattly/tappy in the top end so I think maybe they are slittle too much play.
I will just use the rear wheel to make final adjustments and fingers crossed it is all sweet.
While I’m on the toppic what is with all the marks on the flyweehl? I have a “|T” ant TDC then around further and the “true TDC” I have “F|F” then another 10mm I have another “|T” then there is also a “|” mark halfway around which I’m assuming is “BDC”. I think the manual and all I have read on the net is recomending the secont “|T” mark to adjust from. Is this right?

[Mick DMember]

Dunno what the other marks are for.No doubt TB could shed some light on the topic as he knows a bit more than me when it comes to the donks in a XR600. The second T is the one you use. Have another look and I think you may find that the first one is a “F”. I may be wrong though.

[CarlMember]

Thanks Mick. Adjusted it to the second “T”. Only one little issue I have with adjusting them is I only have a 0.10mm and 0.15mm gauge out of three sets. There is no 0.12mm for the out lets so I adjusted them so I can’t get the .15 in but the .10 slides in and out easily so I’m hoping it is around .12. I have rang around localy here and no one has a set with a .12 in them and have rang the local motor bike shop and they wouldn’t let me borrow thiers so I guess it will be close enough. When it comes to actually adjusting them how much drag do you want on the fingers? A fair bit or just slightly? If I adjust them to just slightly drag on the .10 I can still slide the .15 in resonably easily with only moderate drag so I adjusted them so it was dragging on the .10 a fair amount as not to allow the .15 in. Is that right or is that too tight?

[GregMember]

Everybody has a different feel when setting valves mate. You should have a slight drag on the feeler gauge when you pull in it between the rocker and valve, remember a slight drag. Get a set of the correct clearance feeler gauges as you know already you a 0.10mm (0.003) for the intake and exhaust is 0.12mm (0.004) are needed for the 600.

To adjust take the spark plug out and rotate the engine with the kick starter or like Mick said a 17mm on the flywheel bolt so that the exhaust valve has just open, and then shut and the intake valve is just about to open. You will feel with the screw driver that the piston is at TDC and the T mark will show through the LHS inspection hole. This is not the correct TDC. Rotate the motor a little further and you will notice the intake valve open up. Keep rotating slowly and you will feel the piston rise again to another TDC. This is the correct TDC to adjust the valve clearance from. If you look through the top LHS inspection hole now, you should see the letter T.
Also check the decompression lever adjustment and adjust if required so it is not affecting the rocker arm action and only touches the rocker arm when you pull the decompression lever.

TB

[BillMember]

I dont use feeler gauges as its very hard to get to the valves in some bikes

most ajusters have a 1mm thread pitch ie 1 360 deg turn of the screw from 0 clearance =1mm or .25 =1/4 turn

i find this way more precise also allows for valve stem top dishing and freeplay

[GregMember]

How do you go with bucket and shims Bull :laugh:

[BillMember]

Trailboss wrote:

Quote:

How do you go with bucket and shims Bull :laugh:

Yeh you got drag the old feeler gauge out for that style

[GregMember]

For ease speed and accuracy I would still use feeler gauges. The difference between 0.12mm and 0.10mm via the degrees method would be do much rooting around Bull XR ones have good access anyways

TB

[BillMember]

What ever is easiest for the person on the job

[CarlMember]

Thank you all for the replies. I will give you style a go next time bull and see how it feels. Always willing to try new methods. Hey TB I have been searching the net this arvo and have found a few sets with the elusive .12mm. It is amazing how many go from .10 to .15. And a few that go .10 then .13. It is also amazing how much they vary from metric to imperial. One says .10mm is .003 then the next says .10 is .004. I have also found one that says .003 is .076mm, .004 is .102mm and .005 is .127mm. Even on the two sets I have they are both different with the conversions. Would .01 of a mm or .001 of an inch make that much difference?

[GregMember]

syco26 wrote:

Quote:

Would .01 of a mm or .001 of an inch make that much difference?

No it will be fine, I actually ran on advice my valves on all my 600s at 0.004 inlet and 0.005 exhaust and they did more klms then 99.9% of the bikes here and never ever have I failed a rocker or cam

TB

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