BS38 alternatives

[gggGary]

.............BS38s are no better than any other carbs . .....................
these carbs are a nightmare to get set right and require a new level of Defcon 1 anal attentiveness.
...........

Did you replace the throttle shaft seals, are the shafts a good fit in the bushings? Worn beyond limits, (there is no spec) bushings need to be replaced.....

 

[peanut]

is that @ me G ......or Aussi ?

My BS38s are perfect now..... but it took a lot of work and a steep learning curve.
One of the main issues with mine were the plastic bushes at each end of the throttle shafts . Mine were worn and allowing the throttle shafts to float sideways about 1.5-2mm which in turn caused the butterfly discs to bind at the edges on the wall of the venturi and not shut off properly . Hanging idle was the result.

Edited for clarity and for skulls benefit.
I renewed the plastic bushes and adjusted their thickness so that there was no excess axial float (sideways movement )
I have also added a stronger return spring to give a nice sharp shut off.

 

[kopcicle]

Now for street use and anything over 750cc and over 6000 rpm ...
http://www.pinkpossum.com/GT750/carb/BS40carbs.htm

The BS40 I'm referring to is from the GT750 "L" and yes the Suzuki Savage and the big DR also use the carb.
This is not for the inexperienced tuner. However once you get it right you'll have the experience so never mind.
Also these carbs , even more so than the BS34 and BS36 don't take well to Ethanol or Methanol . Something in the casting. I suspect that it has something to do with Alcohol in the presence of water .

In any case , I'll take the VM carb over a round slide or even a smooth bore. The Keihin CR however a nightmare it is to jet is a great carb. Less said about those over engineered fuel leaks by Lectron the better .

All I got

YMMV

 

[650Skull]

Peanut...........are you saying a stronger spring was used as a means to overcome the slop in the shaft..........

 

[ruso7]

Hi everybody, I¨ve got an engine (I found by de serial number it is xs650 sf, from 78-79), with a frame rear wheel,brake etc all made a piece of crap, rusted seazed, you just imagine thath...No papers, no frame number...And I¨d like to restore it... The engine came with Amal 626 carb, single 2in1 manifold. The needle entering cilindric part is not cilindric form, how u can appreciate on a pics. Will be this a problem to its properly work? Is that better to buy a new carb or keep restoring?
(PS: I¨m not an English spoken person, so ull find a lot of error and horrors here!!!)

20171127_125902

• ruso7
• Nov 27, 2017

20171126_193556

• ruso7
• Nov 27, 2017

 

[fredintoon]

Hi everybody, I¨ve got an engine (I found by de serial number it is xs650 sf, from 78-79), with a frame rear wheel,brake etc all made a piece of crap, rusted seazed, you just imagine thath...No papers, no frame number...And I¨d like to restore it... The engine came with Amal 626 carb, single 2in1 manifold. The needle entering cilindric part is not cilindric form, how u can appreciate on a pics. Will be this a problem to its properly work? Is that better to buy a new carb or keep restoring?
(PS: I¨m not an English spoken person, so ull find a lot of error and horrors here!!!)

20171127_125902

• ruso7
• Nov 27, 2017

20171126_193556

• ruso7
• Nov 27, 2017

Hi ruso7 and welcome,
let me suggest that you will get more and better responses to your post if you start your own string.
No need to apologize for your English, it's way better than my Spanish, for a start.
About the AMAL carb, it's about as simple as a carb can get.
Look it up on the 'net to find an illustrated parts list and dismantle yours to see if any parts are missing or broken.
And please post some photos of the complete bike so we can better advise you.

 

[YamadudeXS650C]

Welcome Ruso7
Very cool that you have an AMAL mounted on your XS..!
Its been years since I've studied the AMAL's on my '69 Bonney, but I think that you are dealing with long-term wear on your 626.
Not sure if it will affect performance, but my hunch is that it will not.
If you do not get the answer you want here, you will get one at the BritBike Forum; the guys there will welcome your question.
But do keep in touch with us here !

Dude

 

[ruso7]

Thanks guys for your reponses, I'll make a new thread(still don't how to start with it).

 

[YamadudeXS650C]

Thanks guys for your reponses, I'll make a new thread(still don't how to start with it).

Just go to Forums, then The Garage, then to Post New Thread.