CARB ID

[stevec8831]

I am pretty sure these are bs38's but i just want to make sure. They came off my 71 project bike, but the guy i bought the bike from owned a motorcycle salvage yard and switched parts around on this bike from different years and makes, so I just want to make sure what I have. There are no kind of i.d. numbers that I can find. Also I'm new to yamaha building and was wondering if it is possible to run these carbs independent of one another? I'm thinking of using the intake manifold I have pictured but not sure if it is even doable. Thanks guys.

 

[grepper]

Those are bs38s. But don't appear to be from a 71. I don't think in 71 they were linked like that. I belive that in 71 they had dual throttle cables.

As for that manifold. It would take some engineering to unlink and make turn them into dual throttle cable carbs.

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[weekendrider]

They are 78-79 38's. Best used with the OEM manifolds.
I won't say you can't rig up something with that intake but most likely you would be just ruining a good set of carbs.

 

[gggGary]

Yeah if you want to go that way, either use after market carbs or early BS38s 70 to 75 are separate carbs. Bet you could find someone to swap if you posted an ad in the classies

 

[650Skull]

As gggary says the carbs you need for that manifold will have to have seperate throttle cables. the 70-75 bs38's are what you need if using XS650 carbs. Those 38's you have won't work if they are split up, In your first pic, the configuration joining the carbs with the springs on it is the throttle shaft and if it is split apart then you would have to rig up some sort of cable to the second carb, and that would be to much work, if it could be done and your choke lever shaft will have to be removed, so only one carb could be choked as well.

 

[stevec8831]

But aren't the later 38's better carbs?

 

[650Skull]

yes, but the problem is because your manifold points out on an angle meaning you will have to split those carbs you have.

 

[stevec8831]

I know, I think I might be able to fab something together for the throttle and choke problem. Sometimes I like to try to do what seems to be impossible. I'll let everyone know how it turns out.

 

[gggGary]

I will trade you a good set of separate BS38 carbs for the linked pair. Trust me this is a much better way to go, you will have plenty of other projects for your fabbing skills. And someone who needs linked carbs will benefit. The "better" later carbs are mainly "better" because they are linked they tune work very similar to the early carbs.

PM or email me?

 

[stevec8831]

I will trade you a good set of separate BS38 carbs for the linked pair. Trust me this is a much better way to go, you will have plenty of other projects for your fabbing skills. And someone who needs linked carbs will benefit. The "better" later carbs are mainly "better" because they are linked they tune work very similar to the early carbs.

PM or email me?

not really at that point in the build yet gggGary. It will be a few months before I drop the motor back into the frame. I'll decide then what direction to take. But if I decide to trade them you'll be the first to know.