Valve adjustments

[tmikeyb]

I'm checking a few things prior to trying to start my 1972 project. The book says that the exhaust valves should be set at .006. When I checked mine they were .008. So I just thought that I'd check with this group and see what you all recommend for exhaust and intake valve settings. Is it best to just go by the book, or do some of you have other opinions. I was always taught that a noisy valve is a happy valve.

 

[CaptCardboard]

I followed this super easy video and my bike didn't explode...

Intake at .003 exhaust at .006

 

[Paul Sutton]

These gap settings are a little tight so ensure yours are not less than 0.003 and 0.006. Originally the gap specification was larger so it would not be a problem if after tightening the lock nut they were closer to 0.004 and 0.007. The gap usually increases a little because the lock nut draws the valve adjusting screw into the rocker thread a little.

From memory I think the old specification was 0.006 and 0.012 so a setting of 0.008 for the exhaust is not really a concern, just a bit noisier than 0.006.

 

[Jim]

Just watched the video. Boy, he sure made that a lot harder than it really is, or needs to be. Turning the crank while sliding progressively bigger feelers in there is overkill to the extreme. It's much simpler....

This engine is a 360° twin. That means the cam lobes are exactly opposite each other. When one side is at valve overlap the valve's spring tension make the crank want to stop there..... right in the middle of the overlap. Actually, that's a bit of a hindrance when you're setting ignition timing... it wants to "lock" the crank in the middle of that overlap, while you need it slightly before that. Anyway....

Let it lock itself there...'cause that's where you need to be. With one side stuck in the middle of overlap, the other side's exactly were it needs to be to adjust the clearances. That's where you set 'em... you don't need to "hunt" for the loosest place.... it's right there.

And yes, 3 and 6 thou. is universally accepted as correct for ALL XS650's.

 

[Its been a long time]

Just watched the video. Boy, he sure made that a lot harder than it really is, or needs to be. Turning the crank while sliding progressively bigger feelers in there is overkill to the extreme. It's much simpler....

This engine is a 360° twin. That means the cam lobes are exactly opposite each other. When one side is at valve overlap the valve's spring tension make the crank want to stop there..... right in the middle of the overlap. Actually, that's a bit of a hindrance when you're setting ignition timing... it wants to "lock" the crank in the middle of that overlap, while you need it slightly before that. Anyway....

Let it lock itself there...'cause that's where you need to be. With one side stuck in the middle of overlap, the other side's exactly were it needs to be to adjust the clearances. That's where you set 'em... you don't need to hunt for the loosest place.... it's right there.

And yes, 3 and 6 thou. is universally accepted as correct for ALL XS650's.

I agree. The XS650 is up there with BMW and Guzzi twins in the world's easiest valve clearance setting competition.

 

[gggGary]