Swap out for bigger carbs?

Well:

-the casting around the butterflies is too thick
-the little nipple with the black cap is odd
-the throttle shafts are nothing I recognize
-there's no idle adjustment screw

I wonder if they're from some other bike.

Look on the sides of all the bowls and see if you can find any numbers stamped on them. May be very faint, but let us know what you can find.
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Here's the back of an xj550 rack (yes I know parts are missing..... it's a parts rack)


Dave

 

Should have kept all this in your other forum--- didn't see that til now---

http://xjbikes.com/forums/threads/xj-550-carbs-1982-seca.109976/

 

Hi everyone. First time post and new to the forum. I was gifted my dad's '81 550 Seca and have been disassembling it to restore it. Got the carb rebuild kits and was taking apart the carb but was struggling with some rusty bolts. I busted off the corner of one of the carb bodies. I'm not sure if this is carb #1 or #4 though (see picture). I've found a couple of used ones on ebay but they are in worse condition than mine and are super pricey regardless. It's a long shot but I'm wondering if anyone here has an extra carb body that I could buy.

Any help would be greatly appreciated. Thanks!!

 

STOP right there. It appears you've already broken the rack, which probably means you're not following the book.

While possibly/probably necessary at some point in the future, those carbs look pretty decent on the inside and may well benefit from the basic service ritual outlined in the manual. DO NOT submerge them in anything until you are ready to remove the butterflies and replace the throttle shaft seals which is not covered in the manual, and not to be undertaken lightly. There is a whole lot that can be done with the rack still together.

If you don't have a factory service manual, you're going to need one. The Clymer 550 book is woefully inadequate for all the stuff you're going to need to do.

How long was the bike out of service? And how many miles on it?

 

Yeah I was using an impact driver to remove a stripped/rusted screw on that corner that is broken now. The bike has been out of service for at least 2 years with fuel in the carbs so I'm assuming it's in need of cleaning. I will order a service manual before I do anything else. For now, I need to find a replacement carb body.

 

Also, the reason they look offset is because I already removed a couple of other parts in an attempt to separate the carbs. They were lined up correctly before that.

 

Let me see what I got

 

Please start a thread for your bike if you haven't already.

Also, do not assume anything. Inspect. Diagnose. Never assume.

 

K-Moe is right you need your own thread for this.

He's also right about making assumptions and jumping to conclusions. Two years parked is nowhere near as bad as thirty years which most of us are dealing with or have dealt with. Even ten years is no big deal, comparatively.

We'll find you a #1 carb body, stay tuned. Don't tear the rack down just yet. Get a factory manual, turn to Section 2, "maintenance" and begin. By the time you get to the carbs, you'll have the part situation solved. Carbs are not the first step in a proper recommissioning.

And start a new thread of your own, please.

 

Hmmm, I was told this when I went to put xj/fj600 mikunis on my non yics 650 - it wasn't. Maybe the 600 spacing is different to 550, but the 600s lined right up. The manifold diameters on the 600 mikunis were slightly bigger than the Hitachis, but maybe the 550s are smaller, and fit straight on. The 600 mikuni air inlet that goes onto the boots were bigger than the hitachis and no way would fit. Lastly the jetting on the 600's was close enough to feel right, but I haven't done any plug cuts or anything else to verify.
All in all a right faff about, so I would avoid if possible.

 

I just took a pic for you @Minimutly
FZ600 30mm Mikuni's and an XJ650RJC (YICS) motor.
This combination is never going to work. 650 YICS or non-YICS are same spacing.

 

Hmmm, so what goes on here then - I assure you the carbs I have (2 sets) were xj600, and both lined right up?
I never respaced them or anything...
Is the xj 600 different to the fj/fz?

 

You guys are trying to compare North American market models to UK models hence the confusion.

 

You're right @bigfitz52 , but what's the difference? Is it the 600 head, or the manifold rubbers?

 

Intake port spacing from the looks of it, so the head. And the fact that they are completely different motors...

 

Here we have my xj600 carbs - Actually BS32's

Xj600 carbs on a 650...

Poo, I tried to post my bs32's next to hogfiddles 550 carbs, and my 650 next to simmy's....

 

Which ones are completely different? Us and uk spec 600's - really?
550 and 600 could be different, but way up earlier in the post someone mentioned fz and fj600's, I would expect the fj and xj600sbto have been the same engine.

 

Similar, but not the same. Yamaha had seperate design groups for each project during that era. Also consider the legal requirement at the time that a certain percentage of parts used on a machine be supplied by other Japanese manufacturers. That's a large part (but not the only part) of why thre are so many models and sub-models of each Yamaha line during the 80's and 90's.

 

So what have we learned? Xj 600 (at least uk ones) carbs spacing is the same as xj650's, xj600s use BS32 Mikunis.
Some of this may be simply down to the carb size - bigger catbs need more room, unless the body sizes were made bigger, and metal left in on the smaller ones.