XS650 reed valve question

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neda

neda

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Hi there,

Could you please confirm that I am looking at the right hose for the valve's installation?

Also, do all vavles need to be drilled as I read up?

Thanks in advance for the help

XS650 reed valve question
 
Yes, my bad I'll resize shortly. To get the full picture now you can right click on the image and open in new tab, it should load fine
 
neda said:
Hi there,

Could you please confirm that I am looking at the right hose for the valve's installation?

Also, do all vavles need to be drilled as I read up?

Thanks in advance for the help

XS650 reed valve question
Click to expand...



Im not familiar with that tank and hoses but im wondering "what" your going to drill on the XS650 valve.. From what i have done and understand from info sourced here the valve is fitted as is with no modifications... Though of course you need to plumb and mount it..
 
Just so happens I've got this area in bits at the moment as one of the airbox clamps has broken off the oiltank:

XS650 reed valve question


Nothing to drill. Pipe you've indicated is correct Neda - the inlet the the right in the following pic:

XS650 reed valve question


and this is the valve installed on a short piece of pipe coming up from the vent at the back of the crankcase:

XS650 reed valve question


Another pipe runs out of the valve up to the tank.

Hope that helps, if you need any other shots just ask. It'll be in bits for another week or so until I can get someone to weld the lug back on.
 
The question is where is that hose coming from. In the previous post, davamb's bike must be a 72 as they were vented at the lower rear of the cases. On a 70, I believe the crankcase is vented thru a disc at the drive side end of the camshaft. There should be a metal hose fitting on the drive side case at that location. You can fit the reed valve at any convienent location in that hose between the engine and oil tank. No need to do any drilling on the reed valve. I didn't.
 
sorry for the delayed response, I haven't had a chance to ride or tinker for months which is a shame. Thanks for all the responses, here are some of the pictures to close the loop and confirm everything before installation

Confirming the location of the hose on the engine
 

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And confirming the orientation of the valve



I understand that the valve can be placed anywhere, but leaning towards placing it behind the left side cover, out of sight.
 

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neda said:
sorry for the delayed response, I haven't had a chance to ride or tinker for months which is a shame. Thanks for all the responses, here are some of the pictures to close the loop and confirm everything before installation

Confirming the location of the hose on the engine
Click to expand...

Unless you removed the rotary breather plate at the end of the camshaft an engine breather valve in that camshaft breather hose is useless.
 
I've got one like yours on my hopper bolted to the front of my battery tray I'm going to cover it with wire mesh to tidy it up a bit. But it is breathing through the timing chest.
J
 
nortonspeed said:
Unless you removed the rotary breather plate at the end of the camshaft an engine breather valve in that camshaft breather hose is useless.
Click to expand...

My understanding is that the breather valve would help create a bit of negative pressure in the engine and help reduce oil leaks. I have had the engine rebuilt, and there's much more compression than before (which is nice). One of the side effect is the leaking and I was recommended this mod by the builder (Rick Harrett of Highway Cycle in Ontario).

Unless it is the wrong hose I'm looking at? (my fear and the purpose behind this post)
 
neda said:
My understanding is that the breather valve would help create a bit of negative pressure in the engine and help reduce oil leaks. I have had the engine rebuilt, and there's much more compression than before (which is nice). One of the side effect is the leaking and I was recommended this mod by the builder (Rick Harrett of Highway Cycle in Ontario).
Click to expand...

Absolutely right! However you do not understand my point: An engine breather valve must be used into a ventilation hose from an unrestricted passage from the crankcase. The camshaft breather is a timed breather so an extra engine breather valve in that hose is useless. An engine breather valve does work fitted into the breather hose from the back side of the timingcover, or fitted into the breather hose from the Combat crankcase breather or machined directly to the crankcase (CNW modification).
 
nortonspeed said:
An engine breather valve does work fitted into the breather hose from the back side of the timingcover
Click to expand...

Which hose is this on the 1970 Commando? Can you please kindly point me to schematic where I can easily identify it?

Thanks for taking the time to respond and helping out, I appreciate it.
 
neda said:
nortonspeed said:
An engine breather valve does work fitted into the breather hose from the back side of the timingcover
Click to expand...

Which hose is this on the 1970 Commando? Can you please kindly point me to schematic where I can easily identify it?

Thanks for taking the time to respond and helping out, I appreciate it.
Click to expand...

I am sorry Neda but your 1970 Commando probably only has the timed camshaft engine breather, unless a previous owner changed the engine breather into the later type breather (breather pipe at the backside of the timingcover, Commando's up from 1973).
 
Neda

Speak to the guy who rebuilt the motor, if he told you to fit that breather to stop your leaks he either knows more about it so he should help. Either that or he may have not turned out a pucker job and is merely getting you off his back. Get him to explain the situation .
J
 
To clarify Nortonspeed's comments, the pre-'71 breather is a slotted disc which is located on and driven by the end of the camshaft, and it butts up to a fixed slotted disc pressed into the crankcase behind the drive-side camshaft bush - hence the 'timed' breather - the holes line up at the appropriate part of the combustion cycle to allow the pressure to exit - all via holes drilled in the cam.
Can't speak from personal experience, but I've read that it was inadequate, and the easiest way to improve matters was to blank it off altogether and fit a '72 type breather on the timing chest behind the barrels (as ultimately done on the 850). This requires holes to be drilled in the timing side crankcase to mount the breather and also through the crankcase chamber itself to provide the clear path. The second part of the Old Britts article shows what's required:

https://www.oldbritts.com/n_c_case.html

This will work great with a PCV.
Even removing all the discs from the cam may not provide an adequately un-restricted path, but I'd happily stand to be corrected.
I kept the angled breather on my PR just for the look of the thing, and have the breather behind the barrels.
 
hi all, the only thing wrong with the timed breather was the holes in the cam,crank case was not big enough,otherwise its perfect,opens when it should and closes when it should,i agree that fitting a xs valve in the timed breather tube is useless,but if it was mine I would leave the timed breather as is,no point striping the motor to remove it,then either drill the rear of the crankcase as per 850 or even the timing cover with a tube to the xs valve,best of both worlds,if one packs up you,ve still got the other,my moneys on the xs packing up first,broken reeds etc. chris
 
neda said:
Hi there,

Could you please confirm that I am looking at the right hose for the valve's installation?

Also, do all vavles need to be drilled as I read up?

Thanks in advance for the help

XS650 reed valve question
Click to expand...

Someone already posted the correct orientation for the XS650 valve. The hole mentioned is actually already in the XS650 valve assembly, and is to allow any residual oil in the valve to flow back through the valve assembly, rather than clogging up the reed valve?

For info :) Broken link removed
 
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