Can you help identify these carbs please

[kevski]

i would like to know what model carbs these are there are no numbers on them only Mikuni stamped on the top covers, they have the pilot adjusting screw on the side, the bike is a 79 stateside special, the carb boots have the vacuum take off for the taps, i am wanting to get new intake boots with stubbs as i have vacuum operated taps.

 

[DIRTY DOG]

they are bs38's can't tell much more with out seeing the air filter side (too see how many holes there are) and the bottom of bowls for any stamped letters

 

[kevski]

There is nothing stamped on the bottom of the bowls, but what i am really after is manifold boots with the vacuum take off, does anyone sell them?

 

[jussumguy]

I found the idle mixture screws on my '79 were machined down on the screwdriver end. And the earlier type has threads all the way to the end. But that's my very uneducated observation

 

[grizld1]

Kevski, the carbs are 78-79. You don't need to see the intake bells, Dog. Absence of vents elsewhere tells the whole story.

 

[DIRTY DOG]

good to know I allways did them by the intake bell holes

 

[XSLeo]

All the carbs on stateside models from 74 up to 79 are all BS38's. They all fit the same carb holders. I would just get the right size carb holders without the barbs and switch to standard petcocks. It may save you a lot of trouble later.
Leo

 

[kevski]

All the carbs on stateside models from 74 up to 79 are all BS38's. They all fit the same carb holders. I would just get the right size carb holders without the barbs and switch to standard petcocks. It may save you a lot of trouble later.
Leo

I would like to keep the barbs for ease of carb balancing with a manometer, my petcocks are all fine and dandy and still operate as they should they have been rebuilt. If they don't make them with barbs any more i will machine a pair up and install them into new carb holders.

 

[5twins]

You can remove the barbs from the old manifolds and install them in the new ones. They are a press fit but can be coaxed out. They are also sealed and/or glued. Tap them in slightly to break that sealer/glue bond then work them out. A slightly smaller hole than the O.D. of the barb drilled into the new manifold allows you to tap them in and have a nice snug fit. I coated mine with Yamabond to insure the seal was good.

 

[kevski]

Will try to remove old barbs first. Just ordered a pair of barbless from heiden in Holland.

 

[weekendrider]

Can't you put barbs on those carbs for syncing purposes?

 

[5twins]

Slip the tin shrouds over your new manifolds and use the slots in them to locate your barb holes. Do continue to use the shrouds, the carbs and manifolds need the added support. Some like to leave them off because they don't like the look. The manifolds won't last as long unsupported like that.

 

[grizld1]

Kevski, if you look between the mixture screw (top) and the throttle shaft end (bottom) on each carburetor, you'll see a slot head plug. The plugs cover 6 mm. threaded ports for installing hose adapters during synchronization. If you don't want to use vacuum petcocks and carb mounts with vacuum barbs with 76-79 carbs, you still have manometer hookups.

 

[weekendrider]

From the pictures, nobody has swapped the choke body so I thought it would work.
If they have swapped the choke body by mistake you have two holes on one carb and none on the other.

 

[XSLeo]

In the pics he posted the outside of both carbs is shown and you can clearly see both plugs.
Leo

 

[weekendrider]

Damn thought that was what I said Leo.

 

[gggGary]

83 BS34's for sure!