xs650 pcv

Hey Guys, I know this topic has been discussed a lot befor but where is the best place to purchase a XS650 pcv valve. I,am going to try one on my MK 3. I have a little oil getting by the head gasket at the push rod tunnel. Just wanted to try the valve for science sake. Thanks Hershey

I bought the reed valve for my 74' 850.
Not on drop from the head and I had been plagued with leaks for decades.
Go here to find the wonder part. No shit, it really works!
http://www.mikesxs.net/search.html?q=reed+valve

+1 what Guido said about supply, MikesXS very good supplier, I am yet to mount and try the valve, but I have heard you should mount as close to engine as possible, so where the breather hose exits, if you have room on your MK111.
Look forward to your evaluation, Richard

Why use a pcv valve when its so much easier to continually replace crankshaft seals and remove the head to try and seal the oil leak from the pushrod tunnels? Not to mention, with the pcv valve you'll miss the fun of trying to seal the tach drive. Also, installing the pcv valve might increase the horsepower too much. Many pitfalls with the pcv valve.

just put a mikes one into my 73 750, now ill have to use my cloths for cleaning the bike instead of wiping the oil off the floor!

That whole thing about mounting it as close to the breather pipe as possible doesn't really matter I think as I have mine mounted
in the battery box.
Having it hang out in the open like looks ugly.
Some say having it close to the engine will keep it hot but if your cruisin' down the pike @ 70 mph then how hot will it be with all that air rushing past.
Just mount it in the battery box for a clean and professional look.

I ordered the pcv valve from Mikes, should get it this week. I,ll let you know the outcome!! Hershey

Hi Guido,

I have not mounted my valve yet, can you shoot a picture? I was pondering on how to mount it nicely in the area in front of the air filter. But if it works in the battery box area, even better!

Cheers Richard

stockie2 said:

Hi Guido,

I have not mounted my valve yet, can you shoot a picture? I was pondering on how to mount it nicely in the area in front of the air filter. But if it works in the battery box area, even better!

Cheers Richard

Click to expand...

Will do.
I mounted it to the air box.








Ever since I installed the breather I have had zero leaks.
I was leaking from between the head and barrels and also at the 3rd fin in the front from the 2 studs in the barrels.
I pulled the head, removed the 2 front studs in the cylinders and locktited them in, used high temp silicone around the push rod tunnels and oil hole.
Put it all together, installed the reed valve and absolutely no more leaks. Could it be from the sealer, the locktite?
Or does the valve really work all by itself. I did all three things but I am sure there are others that just put the valve in and it cured their leaks.
All I know is I am leak free now.
Well, except for the gear box cover that is.
I hope it works for you.
The only thing that should mark it's territory are dogs.

Well I installed the pcv valve and have put about 75 miles in and I think the oil leak between the head and barrels has stopped. More road miles will be needed. I,ve been fighting this leak for a long time. Like I said , it was a small leak but it bugged me. So far every thing is completely dry. Thanks Hershey

It's a beautifull valve at a good price ,just got mine from Mikesxs.

Thanks Guido, nice installation. I have my engine ready to re mount in tomorrow, so I guess I will mount up the valve first.

Thank, Richard

Having a vacuum instead of a pressurized crankcase works wonders for oil leaks. Doesn't it?

On my MK3 I removed the battery and mounted the valve in the foward upper part of the battery compartment where the rerturn hose makes the bend back to the oil tank just below the frame. It will just fit in there without touching the battery or frame. I removed the mounting bracket and just let mine hang free. The hose is sturdy enough to hold it in place. Hershey

Okay Guys, here is the results of the mikes pcv valve. As I stated befor I thought the oil leak around the push rod tunnels had stopped but I needed more road miles. Well aftder another 150 miles the oil leak is still there and just as bad. No help from the valve!! What I did notice is that the oil tank has more oil in it. I ran it for about fifteen miles today and after checking the oil level on the dip stick it showed about a quarter of an inch more oil on it then usual . I keep the oil right on the high mark and have never noticed this befor. I,am also running a antisump valve. Could it be that the zero vacuum in the crank case is causing the oil pump to pump to much oil out of the crank case ??? If this is true then this is not good !!! I,am going to drain the oil in both the crank case and oil filter tomorrow and check the amount of oil in both. Has anybody ever checked these things to see if the valve is doing more harm then good !!! I,ll let you know the results of the crank case and filter oil results. Later Hershey