Carb parts swap question

[76static]

Would the bowls from a 78-79 Bs38 work on a 76-77 Bs38? I also found that the xs360's use the same bowls as the later 650 Bs38. Would they work?

Just trying to figure out a solution to my problem. Thanx

 

[5twins]

'78-'79 bowls should work but you will lose the overflow tube feature. If the carbs overfilled, the gas could only go into the air filter or engine. Not a big deal I guess as that's how it is on a stock '78-'79 set. Yamaha switched to the vacuum petcocks when they made this change. I guess they figured the carbs would never overflow now, lol.

'76-'77 XS500 bowls are another option. Those carbs are darn near identical to the '76-'77 650 set.

 

[76static]

Thanx! Okay, just to be perfectly clear, I would still be jetting them based on the 76-77's because the body, needle, needle jet etc. are the same though correct?

 

[grizld1]

Those tubes aren't just for overflow; they serve to vent the float chambers to atmosphere, and that's necessary for proper atomization. The 78-79 carbs have vents in the back of the intake bell to accomplish this; 76-77 carbs do not.

 

[5twins]

Yes, jet them based on the '76-'77 specs although depending on your mods, '78-'79 spec 27.5 pilots and 135 mains might be just what you need.

Griz, I think the '77 and older carbs vent out the inner sides as well. Granted, the overflow tube is probably doing some of the venting but I don't think it's acting alone.

 

[bluebikerblan]

Hi, I've been noting your float bowl quest for awhile now. There's guy on Ebay who seems to sell a lot of used carb parts including a fair number for our XS650's

http://stores.ebay.com/Smith-Place/...57620919&_sid=113149569&_trksid=p4634.c0.m322

It's not that I'd really recommend going that way....part by part... they get pretty pricey pretty quick but; sometimes we get stuck?

What I might suggest is: it can be really handy to have a "donor" set of carbs like the ones you use (ie. CV's BS 38's 447, 584, 2FO or BS 34) on hand for several reasons including the situation you're in right now for parts. So... like where is a guy going to find a replacement float bowl? or a carb body, or an enrichener, yada yada yada. ???

It's also tremendously helpful to have a spare set to learn and practice on while we're following along the carb guide of the two preceding individuals in this thread (the authors) with your "bleeding eyes" as Leo suggests. To say nothing of robbing a part from now and then.

There are some present possibilities on ebay....

http://motors.shop.ebay.com/i.html?...ccessories&_trksid=p4506.c0.m245.l1513&_pgn=1

Best of luck, Blue

 

[76static]

Yeah Blue, I've come to accept that as my only option at this point, I just started this thread to find out if I were to find a donor set from a different year at a good price, would it be a viable option or if I was stuck with looking a set strictly from my gen ya know. I wish I had realized that the pilot on this carb was this messed up and would cause this much of an issue before I spent the money for the rebuild kits and then the time cleaning them.

I really appreciate the help from you guys.

I closed my first thread in the classifieds for a bowl and started one for a donor set.