Disadvantages to buying torn down carbs?

[xs11bobber]

I've been seeing a lot of this on eBay lately. With any carb set, you're most likely going to want to rebuild them anyway. So what are the disadvantages of this?

I know you may be missing some pieces, unless stated otherwise, but what else? Can't you get all the components for the BS34's if needed? I would guess as long as you're bodies are fully in-tact that you would be perfectly ok. Now is where someone chimes in a proves me totally wrong...

[jjwaller]

I've been seeing a lot of this on eBay lately. With any carb set, you're most likely going to want to rebuild them anyway. So what are the disadvantages of this?

I know you may be missing some pieces, unless stated otherwise, but what else? Can't you get all the components for the BS34's if needed? I would guess as long as you're bodies are fully in-tact that you would be perfectly ok. Now is where someone chimes in a proves me totally wrong...

Just torn down. OR, missing pieces???( That's why they're for sale this way)
Depending on year and model some parts are not available.
Or, some parts are a real pain to replace. Butterfly shaft seals for ex.
in some cases parts can be subed, plastic floats for the brass ones for example,
but, it takes some additional work and tuning. As is the case with the emulsion tubes.

Diaphragm rubbers? If you can find them let me know please!!!
Needles yes, jets yes gaskets yes, slides? don't know.
Again depends on the year and model.

[LuckyEddie]

jjwaller,

Diaphram rubbers are available from www.partsnmore.com .
I just got a set. New ones sure look nice, although not cheap.

[jjwaller]

jjwaller,

Diaphram rubbers are available from www.partsnmore.com .
I just got a set. New ones sure look nice, although not cheap.

Yes, but those are for the later model carbs 81-82,
and unfortunately not for the 78 BS 34's.
Thanks anyway.

[DenyP]

I bought a set for my XS850 that way. They were more or less trashed and missing parts. About all they were good for is a few parts that the PO of the 850 had broke and tried to JB weld. IMHO it's a dice roll at best.

Deny

[Larrym]

Similar but different

Whether you buy carbs in pieces or assembled is going to be an adventure.

My bike came with a rough running problem where the PO's had gone in and out of the carbs so much I just knew there were problems there. But after I went in and checked I didn't find anything obvious. I fixed some small stuff but the problem was still there.

I decided to get another entire bank of carbs so I could swap with the original carbs and find out if the problem was/was not carbs. Got a used set from a salvage yard but had to go through each one and tear it apart. Found out that those carbs had problems: broken posts...stripped jet threads, etc. So I bought yet another bank of carbs which according to the guy I bought it from were "Good to Go."

NOT good to go as same problems were on the newest bank. I was able to swap enough bodies and parts to get one "Good" bank of carbs to serve as my Test bank. Swapped the test bank for the originals and the rough running problem was still there. Led me to the ignition system where I found/corrected the problem.

"Good-to-Go" and "These carbs came off a running bike" didn't turn out so well in my case. Now I've got 12 carbs and one bike. One set of carbs is just a test bank to be used for troubleshooting. One set is a textbook example of just how the carbs can be mangled.

You will find out if the carb bodies really are good/usable only after you've purchased and installed all the parts. By then they will be unreturnable, most likely.

You looking to replace your original carbs cause they have problems or are you trying to build a test bank?

[xs11bobber]

Well... aside from being crammed full of junk including water. The set I have hasn't been completely broken down. I just took the bowls off to see what sort of shape I was in. I'm not a big expert in carberation, but these look in fairly bad shape externally and weren't much better internally. I'm worried about the diaphragms, but I haven't inspected them yet. The choke slide wont move. The 2-piece riveted on cable connector wont budge from rust. Frankly, it looks like a may have a slight case of parts carbs going. I might be able to use the bodies after I CLR them to get the mold and sap off and then Chem-Dip to clean them up. It'd be close to as much work to clean up the carbs as I will have in the entire bike.

[LuckyEddie]

jjwaller,

I sent you a PM.

[tarzan]

Buying carbs together or apart is a crap shoot in my experience.
Ive bought several sets off ebay and craigslist and even if they look
untampered with externally, you never know if they have been tampered with till they are apart.

[xs11bobber]

Update...

I got another set of carbs with my newest bike purchase. Going through them I found a broken float post, broken choke plunger, missing pilot jet plug on #4, stripped pilot jet on #1. I swapped with carbs with #1,4 from another 'dirtier' set. We all know that involves removing the butterflies, throttle shaft, and all that good stuff. I cleaned everything good. Installed the new pilots and mains that came included with the new bike, swapped over newer parts from the removed bodies to the ones that I'm going to be using. Now it's tuning...????????

I've been trying to search for threads on this and have come up empty handed. I don't know what I should be searching for exactly.

But I want to turn my pilot screws out 2.5 turns? Adjust my float heights to ??? for '79 BS34s. Then I will adjust the throttle stops when syncing? I didn't screw myself by re-using 4 butterfly seals did I?

Also if anyone knows where I can find petcock gaskets I'd really appreciate it... Thanks

[DGXSER]

But I want to turn my pilot screws out 2.5 turns? Adjust my float heights to ??? for '79 BS34s. Then I will adjust the throttle stops when syncing? I didn't screw myself by re-using 4 butterfly seals did I?

Many folks report good luck starting at 1-1/2 turns out, 2 is also used commonly. 2-1/2 may be a little rich, but should still start.

For the earlier carbs with the pilot jet screw cap the floats at stock are about 25.7 mm IIRC.

Do the "bread tie" synch before putting the carbs on the bike. It will get the throttles equally open. When the bike runs, each cylinder will pull a little bit different vacuum due to ring and valve wear and such, so you definitely need to do a running synch, but the bread tie should let it start and run. Warning, do not think that because it runs you were magically good or lucky and do not need to do a running synch. Many a person has been on here chasing ghost or gremlins for a long time due to a bad synch.

As to the butterfly seals, well, only time will tell. Either replace them now as a "might-as-well" or get the bike running and check for vacuum leaks to see if you did screw yourself.

[xs11bobber]

I've been searching for the bread tie synch for an hour. No luck as it is so popular everyone must know it... except me, because it's in nearly every damn carb thread . Anyone care to post a link to a forum explaining this to me?

[DGXSER]

There for the asking!!

It is in the tech tips, under maintenance, carburators, pre-synching.

http://www.xs11.com/xs11-info/tech-t...rburetors.html

Read and enjoy.

[xs11bobber]

Update...

I cleaned everything. Did bread tie synch. Air mixture screws 2 turns out. cranked for a little while and nothing. Figured the bowls would need some fuel before much would happen. Choked it, cranked another 4-5 times for about 20seconds at a time and still nothing. I don't smell gas. Should I pull the plugs to see where I'm at and check for something? Petcocks are in right position. Starving for fuel or air and how do you tell? Too much fuel would be fouled or black plugs right. Plugs are new and no real residue present on any. Spark is confirmed on ALL cylinders also.

Also it's a 79F, 4/2 no mufflers(4/1 just swapped back for stock), no air cleaners installed yet, bypassed tipover, TC's fuse block, confirmed working TCI and Rectifier.

I'm not a "carb smart" mechanic. Any help is appreciated. Thanks guys.

[xs11bobber]

Ok... Petcocks were part of the problem. Not sure what's up with them, but removed carbs and noticed no fuel in lines. Reinstalled and set petcocks to prime and watched the fuel flow. So they were starving... but I still can't get anything