Thread size on belt drive pulley and PCV question

[brasstinman]

Hi,

I've got the all too famous pressure build up problem within the crankcase and have a replacement seal but need to get in there to replace it.

Does anyone know what size thread bolt fits into the belt drive pulley to ease it off?
See pic below circled in red.

Also I wanted to get the Yamaha XS650 PCV reed type valve part number 15-0677, does anyone know if this can be bought in Australia?
I've been ringing around dealers, smash repairs and looking online and I can't find any place in Australia that sells it. I have a link to this web site if I can't find it here in Australia. I'm located in Sydney.
http://www.mikesxs.net/products-40.html#products

Does anyone know what pressure rating the PCV for the XS650 has and I could source another brand.

Thanks in advance for the help.

 

[RennieK]

Hi, that may depend on the make of the kit. Those alternator studs in the inner cover look close. I think I used to use crank case studs for the original triplex sprocket.

 

[kanaka]

Hi there as far as the xs PCV valve I bought mine from Mikes and was delived within a week I am in Brisbane Australia so you should be fine if you need something in a hurry go to repco and order a PCV 001 there are off a 186 holden red motor and do the job and cost about 20 bucks

 

[L.A.B.]

Does anyone know what size thread bolt fits into the belt drive pulley to ease it off?

I would have thought they are going to be either the standard engine sprocket extractor bolt thread size (5/16" UNF) so the pulley can be removed with the normal extractor, or they could be metric (M8 coarse?) I suppose?

 

[JimC]

I've got the all too famous pressure build up problem within the crankcase and have a replacement seal but need to get in there to replace it.

If you are going to install a pcv valve, wait with the the seal replacement. You may find you don't have to replace the seal. I'd wait for the Yamaha XS pcv valve, they do get the job done. As for finding those valves, I not so certain they were an original item on the XS 650.

 

[ML]

I'm chasing one too. The reed valve XS breather seems peculiar to US Yamahas. I've contacted Yamaha Australia and they don't have anything on their stock listing, checked Yamaha Owners Club 650 experts and they admitted they've didn't have anything similar either.

Looks like the best bet is Mikes XS web supply at $16 which is pretty good.

Mick

 

[Ron L]

The reed valve XS breather seems peculiar to US Yamahas

The reed valve is NOT a Yamaha part. If it were Mike's XS could not afford to sell them for $16! :lol:

It seems Nortons aren't the only vertical twin that can benefit from some backyard engineering!

I suspect the valve is from a piece of commercial lawn equipment, small tractor, or generator. I'd be curious to know just it was originally designed for. I'll bet it is pretty common.

 

[nomadwarmachine]

Has anybody got a DETAILED photo of the PCV valve installed on a bike (particularly if that bike is a 1973-74 850)? I've got my valve and am trying to figure out how/where to mount it and route the hoses. I've searched and seen some postings but nothing that really shows me where to drill/mount the valve.

Got the CNW check valve on the feed line this weekend. Already leaking less.

 

[brasstinman]

Has anybody got a DETAILED photo of the PCV valve installed on a bike (particularly if that bike is a 1973-74 850)? I've got my valve and am trying to figure out how/where to mount it and route the hoses. I've searched and seen some postings but nothing that really shows me where to drill/mount the valve.

Got the CNW check valve on the feed line this weekend. Already leaking less.

There was a post on here somewhere that I saw and it showed a diagram of the oil tank and lines heading to the crankcase. In the diagram it was line 47 which you need to cut and install the PCV valve into. It's the breather oil line that comes from the top of the oil tank and runs down under the backbone and you'll find a joiner which expands to a larger diameter line that then runs to the case. I suspect the joiner is there so if you wanted to remove the line or crankcase you can just pull the line off and not have to undo it at the oil tank. ???
Anyway do a search on the site for PCV and there will be a drawing diagram post showing the line I'm talking about.

 

[brasstinman]

Started another reply to keep the PCV and the thread topics slightly seperate.

I (well my father did while I was at work) found out what size the threads were for pulling out the belt drive pulley. It was 3/8 UNF fine.
The old man and I made up a pulley device to gentley pull the pulley off and we can now get to to the brass ring and the seal.

Now we're not sure how we're going to get the seal and the brass ring out because we don't have a right angled tool which is usually inserted in behind the seal and the brass ring and then you can pull them out.
Besides just prying a thin screw driver in there and slowly and carefully working the brass ring out we're just sitting there evaluating the options at the moment.
Anyone got any ideas?

 

[brasstinman]

I'm chasing one too. The reed valve XS breather seems peculiar to US Yamahas. I've contacted Yamaha Australia and they don't have anything on their stock listing, checked Yamaha Owners Club 650 experts and they admitted they've didn't have anything similar either.

Looks like the best bet is Mikes XS web supply at $16 which is pretty good.

Mick

I did the same thing on Sat and called half dozen Yamaha places and even sent two emails out to this bloke in the XS650 club here in Sydney who restores XS650 and another to this guy who sell parts locally for the XS650.
Both of them hadn't heard of the valve being used to stop possitive pressure build up. I was suprised at that because it seems to be used in the US to stop the problem. I should ask them what they do if they don't use the PCV valve.
So I called British Spares which is out on Parramatta Road and the guy there said you need to drill the crank case and install a valve in that. Think I'll pass on that.

I'll be ordering my valve from MikesXS tomorrow. I'll let you know how quickly it arrives.
I wish I knew what pressure rating this valve was so I could confidently get another. I know kanaka said to use the PCV 001 from a 186 motor Holden but I'd like to know the ratings of both so I know they match up before installing something that might end up just allowing the seal to leak again. I'd rather do the job once the right way if you know what I mean.

 

[Ron L]

Now we're not sure how we're going to get the seal and the brass ring out because we don't have a right angled tool which is usually inserted in behind the seal and the brass ring and then you can pull them out.

I believe the "ring" you refer to is part of the seal. I usually screw in two sheet metal screws 180 degrees apart and using a couple pair of pliers, pull the seal out.

 

[brasstinman]

Now we're not sure how we're going to get the seal and the brass ring out because we don't have a right angled tool which is usually inserted in behind the seal and the brass ring and then you can pull them out.

I believe the "ring" you refer to is part of the seal. I usually screw in two sheet metal screws 180 degrees apart and using a couple pair of pliers, pull the seal out.

Thanks for the heads up Ron L. I'll give that a go tonight.

Just about to order the PCV valve from MikesXS and it's a whpping $25.40 US to ship it to Sydney Australia. Man I hate UPS, they're always as dear as poison.

 

[brasstinman]

New seal has been installed and my XS650 PCV reed valve arrived today.

Question is which end of the valve goes onto which part of the line?

Can't seem to find any details install instructions anywhere on the site or on the internet.

 

[JimC]

Inlet to crankcase, outlet to oil tank.

 

[brasstinman]

Inlet to crankcase, outlet to oil tank.

Thanks for the reply JimC. Figured that might be the case but didn't think it would harm to ask before installing.
I only want to do this once, the right way.

 

[JimC]

There was a post on here somewhere that I saw and it showed a diagram of the oil tank and lines heading to the crankcase. In the diagram it was line 47 which you need to cut and install the PCV valve into. It's the breather oil line that comes from the top of the oil tank and runs down under the backbone and you'll find a joiner which expands to a larger diameter line that then runs to the case. I suspect the joiner is there so if you wanted to remove the line or crankcase you can just pull the line off and not have to undo it at the oil tank. ???

Line #47 is the tank breather hose. It goes to the air box on a stock air cleaner. The XS PCV valve goes between hose #44 and #45, replacing adapter #46.

 

[Hungry J0e]

Also installing the PCV... just to be clear I understand correctly how all the lines should run, where should line 44 be connected to on the case on a Mk III 850?

Cheers,

- HJ

 

[JimC]

The Mk III breathes through the timing chest. #9 is the breather exit. The inlet on the XS PCV valve connects to it.

 

[plj850]

New seal has been installed and my XS650 PCV reed valve arrived today.

Question is which end of the valve goes onto which part of the line?

Can't seem to find any details install instructions anywhere on the site or on the internet.

Yes you can blow through it and the end you can blow through connects to the engine side of the breather.....