Trying to find a new or used set of carbs

[zwerlus]

Hi All, been awhile since I've been on here.  Recently had my  bike looked at after being unsuccessful at getting it to start. After the shop took a look at everything they determined that I'm going to need either new or a working set of carbs. I've looked into Bike Bandit to see if I can piece them together but I'm not sure exactly how to piece one together.  Can't seem to find any on eBay either at the moment.  Would piecing a new one be the best option or should I continue to search for a used set?

[Squishy]

What?
The only thing wearing on your carbs are your needles, emulsion tubes and diaphragm.. and those can be replaced.

[zwerlus]

Ah, that makes sense.  I'm getting it back from the shop today so I will have a better understanding as well. Thanks!

[greg737]

What?
The only thing wearing on your carbs are your needles, emulsion tubes and diaphragm.. and those can be replaced.

Don't forget the rubber bits, they age/wear too!  If you're going to refurbish a set of Mikuni BST32s or BST33s (depending on your Bandit model) you should treat them to a complete set of high quality Viton from Litetek.  http://litetek.co/Carb_Kit_Suzuki_GSF400.html

[zwerlus]

Awesome, I'll make sure I do!  Thanks for the link too!

[ventYl]

the only other legit reason for replacing carbs is unavailability of powerful enough ultrasound to clean your current (as did I) or finding out that previous owner FUBARed (read as: tuned) your current set.

[zwerlus]

Good to know, as far as I know nobody has tried to tune it.  It ran w/o issue up until last year.  I was just surprised that the shop said completely new carbs were needed and that a rebuild wouldn't  be enough.

[zwerlus]

So to recap - Diaphragm, needles, emulsion tubes and rubber bits should help me get back on the road. Never rebuilt one myself but I do have help from somebody that has. Can't wait to order the parts

[greg737]

The first step in your refurbishment effort is to disassemble and inspect.  The diaphragms might be in fine condition, you don't know till you carefully inspect them.  Same for the slides and the emulsion tubes. 

Whether or not the emulsion tubes are worn depends on the needles.  If the needles had "play" in them, if they were able to "waggle" back and forth a bit at their attachment in the bottom of the slides and come in contact with and rub on the tubes, you'll have tube wear.  But that's not always the case, especially if nobody ever messed with or changed out the needles (usually done to rich-up the bike for a little more performance).

[greg737]

Also, you shouldn't attempt to work on Mukini or Kiehin carbs with good-old fashioned Phillips screwdrivers.  The screwheads aren't Phillips, they're JIS (Japanese Industrial Standard).  Phillips drivers will ruin JIS heads.  The easy to find JIS substitute is drywall driver bits from Home Depot.

[ventYl]

or better invest three to four bucks and replace JIS cross-type screws with allen heads.

[vintagemilano]

One thing not mentioned yet and depending on where in the world you live but corrosion of the metal parts could render a whole set of carbs non rebuildable. If you are concerned about doing it yourself you can always leave one assembled incase you can't figure out how to reassemble. You will likely have to order bits from several sources, just a heads up on that. You will probably need need little plugs that get squished in by the float assembly at the bottom of the pilot circuit.

[Chris H]

They aren't too complicated so if you got some basic mechanical skills you will be ok.
I'd say do one at a time, don't strip the complete set down.
Watch those screws they are very soft and easily damaged.
On rebuilding the emulsion tubes they only go back one way around, there's a tab they fit into.
Do not screw them pilot screws down, they only need to be very gently bottomed so you can count the turns back out, many a set screwed by people whacking them home and opening the base hole up.

Any problems just ask and someone will help.

[zwerlus]

Thanks for all the help guys!  I'm going to try and see if I can get some JIS screwdrivers, I wouldn't want to ruin the screw heads.  One thing I was wondering (I asked greg737 this a bit a ago) is if I need a specific jet kit for my elevation? I'm in Salt Lake at about 4500-5000 feet.

[ventYl]

convert the screws to to allen head, if metric ones are available in your area. off-the-shelf screws tend to be a little longer to fit clearly but chopping them to match old ones length solves the problem. they also look more hardcore