PCV Valve Location

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chasesa

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On a 850 Mark lll with the air box, where is the best location suggested to place a PCV valve? (I have decided to retain the box for now).

There certainly isn't much space.
Cheers!
Stephen
 
Hi,
The closer to the crankcase you can get it the better. However, many have reported getting the desired effect (IE less oil leaks) placing the valve most anywhere in the breather hose.

GB
 
I was able to strap the XS650 valve on the back bone right under the front of the seat so that it is pointing its exhaust tube at the oil tank breather tube. I didn't do this because I thought it was mechanically the best decision, but rather that it was better there than not having one at all. I would think that creating any kind of vacuum would work better without a length of rubber hose between the case and the valve. I just didn't want the thing located below my carbs.

I think the best solution is the variety of different proposals that have the valve attached by rigid means to the case. I just haven't gotten their yet. I can't report any negative feedback on the present installation, but any claims to the positive would be purely subjective.

Russ
 
I am using the XS650 PCV valve from Mike's XS.

It involves some gyrations, but I think I can get it under the battery tray forward and behind the airbox lower mounting bolts. That places it within 5" of the crankcase vent.

However, it's tight & I wish to avoid it rubbing on the tranny top.

Will report tomorrow.
Stephen
 
OK, the job is done with minimal gyrations!. I was able to fit the Mike's XS PCV valve above the transmission.

It was fairly easy to feed the breather tube to the oil tank without interference from the airbox.
Stephen
 
chasesa said:
OK, the job is done with minimal gyrations!. I was able to fit the Mike's XS PCV valve above the transmission.

It was fairly easy to feed the breather tube to the oil tank without interference from the airbox.
Stephen
Click to expand...

Like this?

PCV Valve Location

combat-proddy-build-t4186-120.html#p60404
 
Except that I would imagine his breather comes off the timing chest.
 
I put an xs 650 valve up behind the air filter and under the seat near the oil tank. It's to relieve pressure in the crank case so why does it matter where you put it?
 
You will reap the benefits where ever you put it. However, it is said to work better close to the case. The length of hose may rob some of the vacuum for which it produces.
 
I never thought about the hose length, but it makes sense to a degree. I don't think it would really make much difference though, thanks pvisseriii.
 
britbike220 said:
I never thought about the hose length, but it makes sense to a degree. I don't think it would really make much difference though, thanks pvisseriii.
Click to expand...

I agree! It was always my contention that unless you have it incorporated to the cases, putting it further from the case would help keep oil away from the reed valve and hence hindering its action.
 
When it comes to flow - short fat pipes win. If you want to optimize the vacuum effect of a reed valve, put it close to the source.
 
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