Xs650 mount near tank or breather?

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rgrigutis

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Replumbing the oil lines on my '72. Read most everything on here about this topic and it seems 50/50 as the most advantageous location to mount the xs650. I suspect it's easier to mount up by the tank. I've got everything apart so I could easily mount it right atop the breather if it works more effectively there. Or does it not
make much difference. Thanx, Rick
 
Mounted mine by the tank. Not having tested it out yet, I'm not sure hw much of a difference it makes... it is a vacuum we're talking about here after all...
 
mounted mine with super velco on the very back of the air cleaner cover months ago, little oil leaks virtually eliminated
 
In theory the closer to the crankcase the better. But unless the valve has a good way to drain oil back into the engine sometimes it's better to mount it higher. This is apparently why it's popular to move the Ducati breathers away from the engine, the drain holes can't keep up and it gets all congested.

And I forgot to mention... post pictures of you installation! :mrgreen:
 
I mounted mine close to the oil tank. The fit was perfect, the valve is hidden by the seat so it is unnoticeable, the install was way easier, the results were better than expected. Even over winter storage the oil that leaked out of the crankcase was less than 1 oz. and I still have oil showing on the oiltank dipstick. Performance was noticably increased first ride after installation, and as mentioned, it's a vacuum system, so I doubt there is much difference if you mounted the valve closer to the engine.
 
Even over winter storage the oil that leaked out of the crankcase was less than 1 oz. and I still have oil showing on the oiltank dipstick
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Are some people here getting confused between breather valves and oil fed non-return valves?
 
I'm pretty sure the breather doesn't have anything to do with wetsumping. The only thing I can imagine is that less pressure in the crankcase makes the oil pump work better and leave less oil in the crankcase, hence you may see less oil there than before? Or that having a positive seal on the breather prevents oil from draining from the tank? Dunno.
 
This position near the oiltank works good to me. Bolted to backplate of airbox.
No oilleaks for 300 miles and power as usual.

Xs650 mount near tank or breather?
 
Re: Xs650 mount near tank or breather

Thanx boys
if I can strongarm my son into helping me Sunday I should have the motor and tranny assembled into the cradle ready to slip the frame over it and in place. This will give me a better perspective on how and where to mount the valve. I'll post some pics.
 
Re: Xs650 mount near tank or breather

rgrigutis said:
Thanx boys
if I can strongarm my son into helping me Sunday I should have the motor and tranny assembled into the cradle ready to slip the frame over it and in place. This will give me a better perspective on how and where to mount the valve. I'll post some pics.
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breather-clearance-t5855.html

Xs650 mount near tank or breather?


I was thinking there might be enough room just above the stock breather and below the air cleaner, but I don't know.
 
I was planning to buy an xs650 when I was in the US in but in reading a lot of info re the Bunn system I am going to go with that now; seems more effective from all the testing info. I'd at least take a look at the Bunn before buying this valve. There are some links in the "Intake Rocker Breather" thread.
 
mike996 said:
I was planning to buy an xs650 when I was in the US in but in reading a lot of info re the Bunn system I am going to go with that now; seems more effective from all the testing info. I'd at least take a look at the Bunn before buying this valve. There are some links in the "Intake Rocker Breather" thread.
Click to expand...

I read the Bunn stuff and was not impressed. If you read all of the prodigious writing you'll see it's thousands of words that don't really say anything.

What you're basically buying is a cheap plastic valve and some tubing for what, $100? I'll pass.
 
"I read the Bunn stuff and was not impressed. If you read all of the prodigious writing you'll see it's thousands of words that don't really say anything."

Though I agree that the price is high for the parts involved, I had the opposite impression. Bunn has done a bunch of testing and published what he found. Whether one agrees that the published results are actually of real benefit or not, he has, at least done research and testing. OTOH, use of an XS650 valve has no similar testing by anyone that I can find. Heck, no one even seems to know what the valve was made for in the first place! :)

A side note, totally unrelated to the post...I'm writing this at the moment sitting in a room in Marrakech, Morocco (business meeting); Ain't the internet great?
 
mike996 said:
"I read the Bunn stuff and was not impressed. If you read all of the prodigious writing you'll see it's thousands of words that don't really say anything."

Though I agree that the price is high for the parts involved, I had the opposite impression. Bunn has done a bunch of testing and published what he found. Whether one agrees that the published results are actually of real benefit or not, he has, at least done research and testing. OTOH, use of an XS650 valve has no similar testing by anyone that I can find. Heck, no one even seems to know what the valve was made for in the first place! :)

A side note, totally unrelated to the post...I'm writing this at the moment sitting in a room in Marrakech, Morocco (business meeting); Ain't the internet great?
Click to expand...

Research? It reads like snake oil.
 
OTOH, use of an XS650 valve has no similar testing by anyone that I can find. Heck, no one even seems to know what the valve was made for in the first place!
Click to expand...

It was originally designed for the Norton Commando, but was rejected as a cost cutting measure. Sound plausible? As for testing, a lot of Nortons are running the XS 650 PCV valve. The only complaints I've seen here is that it doesn't stop the wet sumping problem. Duh? If you want to get rid of the oil leaks on your Norton, hang a reed type check valve on it (assuming all else is up to snuff).
 
Anyone that thinks a crankcase breather valve can have any effect on wet-sumpling must have a very poor knowledge of engine design and operation.
 
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