should carbs be joined with a bracket?

[john650]

Hi, I should putting the engine back in tomorrow.
One question, (probably more to come); my standard carbs are not mechanically attatched to each other. There is a rubber pipe interconnecting the chokes at the front, and a rubber interconnecting fuel pipe at the rear. So should there be brackets between them, even though the throttles are unlinked ? I'm sure that I have seen a bracket on ebay which links the tops of the vacuum chambers, but I,m not sure if it was fitted to my 1975 model.
I would be grateful for advice on this.

 

[jetmechmarty]

The carburetors on your XS650B are not joined by a bracket. That began with the XS650C.

 

[john650]

The carburetors on your XS650B are not joined by a bracket. That began with the XS650C.

Ok, thanks for the info, Jet.

 

[DogBunny]

5twins has said that putting the top butterfly-shaped bracket from a linked model onto one of the earlier unlinked models is an improvement. It makes the carbs support each other, stabilizing both, reducing vibrations in the carbs, and making the carbs more secure in their carb holder boots. I would definitely seek out that butterfly bracket if I had unlinked carbs. If you have the very early straight carb holder boots, I think you would have to change to angled carb holders before putting the butterfly bracket on would be possible.

 

[john650]

Yes, I think you are right about the stability, thanks.
I'll try and find one or just make one.

 

[jetmechmarty]

Like this, but the vibration may break it.

 

[john650]

Yes, just like that.
I like the cutout for the engine breather pipe at the back.
There's not much room around the back of the carbs is there?
Or under the fuel tank, where choke, throttle and HT leads live?

 

[5twins]

You don't need the hole in the bracket. The originals didn't have that. You do want the rear cut out as shown though to clear the frame and to allow room for the clutch cable to route down through .....

 

[john650]

Aaah ........so thats where the clutch cable routes! (Mine is stuck outboard of the left hand carb).
So where is the large, virtually unbendable engine breather hose supposed to go then?

 

[5twins]

That would depend on the year. Early models went straight back over the carbs and then down into a hole in the left side cover, ending up over the chain. Sort of a built-in auto chain oiler, lol. Later models went straight back over the carbs and attached to the tops of the airboxes. Oil vapor was recycled through the engine. Your hoses are hard because they're old. The replacement hose from MikesXS is wonderful and highly recommended. It's soft and supple, and it matches the O.E.M. sizing perfectly (diameter, wall thickness). This is important if you wish to re-use the coil protection springs installed on the original hose. You can get an automotive hose that fits the nipples but it's O.D. is so big, you can't use those coil spring protectors anymore.

If you're going to run pods, most of us install one-way check valves (power brake booster valves) in the end of the hoses and poise them above the pods. Any oil mist or drips that come out will simply get recycled through the motor, something like the newer original set-up .....

 

[Scrambled]

I have asked at a couple of local auto parts stores and they ( the counter dummies ) don't know what I am talking about . Is there a part reference # or something ?

I ordered new hose from XS direct and it was a really cheap thin wall .

 

[5twins]

Yes, but that number may vary depending on the maker. You find them in the "Help" aisle on a plastic card, not behind the parts counter. They're a generic fix-it-yourself part .....

 

[Scrambled]

OK , I will have to try a few other stores . I did look at the DIY section , figured I would at least find some sort of check valve but there was nothing like that . I may have to venture into the heart of darkness itself , otherwise known as Wal-Mart .

 

[5twins]

The supplier of the ones I got is Dorman. You can probably Google it and find it.

 

[DogBunny]

Dorman 80189 also works, it is the exact same valve with a couple of added grommets in the package. Some auto parts carry 80190, some carry 80189. Lots of variety in pricing and availability from different stores, the packs with the grommets from O'Reillys are a few bucks less than the plain packs from Advance.
Always open the package and test by sucking/blowing before buying. Air should go one way, but not the other. An amazing percentage are bad when new. Check and replace once a year. They are not intended for hot oil mist, and don't last very long. Hang on to the receipt, they have a one-year warranty.

 

[Scrambled]

I haven't seen any mist come out of mine yet, and the stock air boxes were clean as well . There dosen't seem to be any oil residue in the original hoses either . Is this normal ?

Thanks for the part #s .