Changing out the double petcocks.

[stanleyh]

I was wonder if I need both original petcocks on my 78 xs special? I'm not familiar with these vacuum type. They both leak in any position all the time. Can I just T off of one of the petcocks and cap off the other one? Can I just run these original bs 38 mm carbs off of prime position and install a shut off valve below the petcock? thanks stan

 

[weekendrider]

Yes you can. The problem would only be the little amount of gas not available on the blanked off side.
There several threads on petcocks that should help you repair yours so they don't need an extra shutoff valve. It is crowded enough in that area without adding stuff.

 

[stanleyh]

It busy like you say in there for sure. I took your advise and found the petcock repair kits for $32 dollars, @mikesxs and I am going to get those. Thanks for the advise. stan

 

[gggGary]

Yup read the excellent petcock overhaul thread I "borrowed" from the XJ site. Flat sanding and buffing the selector and the inside of the petcock where the selector seal rides are important IMHO. If they are in good shape the original C section selector seals are probably better than O-ring replacements.

 

[stanleyh]

Thanks for reply. Whats IMHO?

 

[gggGary]

In My Humble Opinion.

 

[Scrambled]

Yah ! Who are you calling an IMHO ?

 

[stanleyh]

I just bought a clean 78 dark factory blue 650 special with the factory aluminum solid wheels. I haven't seen one yet in the hundreds of picts I have viewed online. Info sites on what color each years bikes are does not even show the blue as a option till 79. I love the color and the original paint still looks great. Does anyone ever see factory blue one anywhere?

 

[gggGary]

Speaking of pictures..... LOL The factory blue and green 78 "standard" model tanks have a gold tank stripe that completes a loop, the 79 blue has a shorter gold decal. Standard tanks are bigger and the gas filler is centered, the specials have the filler offset to the right. They interchange.
According to the Aussie site "buyers guide" which I have found to be accurate, these were the available 78 colors.

[FONT=Verdana, Arial, Helvetica]XS650E[/FONT] [FONT=Verdana, Arial, Helvetica]2F0-000101[/FONT] [FONT=Verdana, Arial, Helvetica]1978[/FONT] [FONT=Verdana, Arial, Helvetica]Star Black, Spruce Metallic Green[/FONT]
[FONT=Verdana, Arial, Helvetica]XS650SE[/FONT] [FONT=Verdana, Arial, Helvetica]2F0-100101[/FONT] [FONT=Verdana, Arial, Helvetica]1978[/FONT] [FONT=Verdana, Arial, Helvetica]Vintage Burgandy, New Midnight Black[/FONT]


A 78 standard "found on the web"

Here's the 79

So you may have some "replaced parts"?

 

[stanleyh]

I think even though all no.s match and it is the special with the offset filler cap, the blue color and alum mags lean me to thinking it must be a late model 78 or a 79 model. I still have not seen a blue one yet. Sorry to bother you cosmetic ?s. thanks

 

[stanleyh]

I appreciate the site you referred me too!

 

[XSLeo]

In late 78, 79 and 80 they used the disc brake mag wheel on the rear of the Specials. In 81 they use the drum brake mag. I assume that's what you meant when you said "aluminum solid wheels".
Leo

 

[stanleyh]

I think the " late 78 " is probably what I've got. And mag wheel is what I was meaning to say. Thanks

 

[bluebikerblan]

The charts not-withstanding, there were significant numbers of cobalt blue 78' XS 650 SE (Specials with cast alloy wheels and disc brake rear wheels) produced. I have one and have seen several more. Most that I know of had VIN numbers which began with "2MO". Best, Blue

 

[stanleyh]

Thats what I have then. Would like to see any pics you have. Regardless I appreciate that information. I do like the color for what thats worth.

 

[XSLeo]

Mike's sells a nonvacumm operated petcock to replace the vacumm petcocks. They are out of stock right now but the rebuild kits are $30, the petcock is $46.
If they had them I would go with the non vacumm replacement.
Leo

 

[gggGary]

XSLeo have you used the mikes petcocks? Just wondering how good they are. I just got a bike in with them on. I haven't opened them but the PO had them slathered with some sort of sealer. Just wondering if they are any good... On the other hand I just installed his overhaul kit on a set of non vacuum petcocks and so far so good.

 

[XSLeo]

I have not used them. The 75 has manual, the 81 has the vacumm and the only trouble so far was they wouldn't shut off well. With the tank off gas would drip out. I fixed that just by flipping the rubber washer over. The one with four holes under the lever.
As we all know Mike's quality can vary. Maybe that's just a bad set. It is a good idea though.
Leo