Carbs from a 700x on a 700N

Wondering if carbs from a 700X Fit on a 700N. i cam across a set thats real cheap and well only difference i seen was the jet that was located in the inlet port that goes into the intake manifold. please let me know if its a doing thing or not.. if so then i can get this set real cheap and will have a spare to cabage from if need be in the future.. or have a set ready to rock n roll.

 

The 700n came with 33mm Hitachi carbs while the 700x came with 33mm Mikuni carbs. The Mikuni's are slightly different and better, but will work in place of the Hitachi's. Most of the parts (if not all), are not interchangeable.

 

How are they better? Just curious.

 

I have two early 80's 750's: an XJ Seca, and an Kawasaki GPz. The Seca had Hitachis, the Kawasaki has Mikuni BS34's. The one thing I can say seems better to me on the Mikuni's is that you can still get parts, like, say, new needle jets, for them.

OTOH, I haven't even tried to find Hitachi parts in a number of years. Maybe the availability has improved from what I remember.

 

Just what I've heard over the years from mechanics. I can personally vouch for the fact that Hitachi makes crappy altenators, starters, regulaters and rectifiers.

 

Draw your own conclusions, I guess, but Hitachi also made the stock XJ ignition coils (and probably most of the rest of the ignition system).

The GM Saturn coils I put on my Seca were also made by Hitachi. I'm quite happy with those.

They used to make some very nice lateral MOSFETS. They also used to make some of the best bang for the buck CRT's, and the best O'scope I ever used back when I was a bench tech was a Hitachi.

I don't much care for their carbs, though.

 

The mikunis IMO are much more finicky with settings and tuning.
Choke linkage is different but would probably work.

I would have to measure, but I THINK the Mikunis are a bit longer (which would probably still be OK)

Sorry Orange and Black, but I don't think there is one single part that is interchangeable.

 

What I meant to convey was that a rack of Mikuni carbs will work in place of a rack of Hitachi carbs as long as they are the same size. The individual parts probably wouldn't. As for the Hitachi electrical parts are concerned, my experience was with automotive. Could be that the Hitachi electrical components on motor cycles are sufficient due to less demand on said parts or they are made differently. Or it could just be my baseless opinion.LOL

 

Just Say No!

There are so many varied differences in throat size, flange size, throat spacings, etc. between the BS33 Mikuni and the HSC33 Hitachi carbs that, unless you're a glutten for fabrication punishment, will make the installation and use of X carbs on non-X models a nightmare. And after that, you can then attempt to tackle the throttle and choke linkage fabrication nightmare, as those are different, too (and in the case of the choke linkage, operate in completely different orientations; the Hitachi carbs use choke plungers that "pull up", while the Miks use a choke plunger that must be "pulled OUT horizontally" ).

But that's just my personal opinion!

Hitachi and Mikuni carbs of this era are basically identical to each other in operational theory and performance, and all conceivable necessary rebuild parts are available for both.

The Hitachi carbs are actually a bit easier to work on, as there is no "pilot fuel jet inside a sunken well" nor the "friction-fitted float pin that will eat the pillar post" issue on those carbs that the Mikuni's have. Additionally, Hitachi carbs have replaceable main air jets, while the Mikunis have a fixed and basically non-replaceable main air jet, for some odd reason........

 

Are the carbs from the U.S. model XJ700X the same as the carbs from the Canadian model XJ750X?

 

Yes they are, but..........




MIKUNI MAIN FUEL JETS:

Stock Mikuni XJ series carbs used the following original main fuel jet sizes:

#100 1985 all XJ700-X models (*see note below)
#100 1991-94 XJ900 models with BS36 carbs

#102.5 XJ900RK US & Canada with BS35 carbs
#102.5 XJ900RL and XJ900P (31A models) with BS35 carbs
#102.5 XJ550L (1984) on cylinders #3 and #4

#105 1986 all XJ700-X models and all XJ750-X (*see note below)
#105 XJ550L (1984) on cylinders #1 and #2

#107.5 XJ900 most 1984-90 models with BS36 carbs (except USA or Canada)

#112.5 XJ550 all models and XJ1100

#125 XJ650 Turbo carbs for all cylinders (**see note below)

#127.5 XJ650 Turbo carbs for cylinders #1 and #4 (**see note below)

#132.5 XJ650 Turbo carbs for cylinders #2 and #3 (**see note below)

NOTE:
* there are discrepancies between the parts manuals and the service manual information on the size of the 1985 XJ700-X main fuel jets; one source claims these carbs were equipped with #100 main fuel jets, while other sources claim a #105 size main fuel jet. Our experience leads us to believe that the correct size for the XJ700-X and XJ750-X models is the #105 size for both the 1985 and 1986 model years.



Also, the 750-X carbs came with the 5FZ83 main jet needle, which is the same as the XJ700-X(C) models (C = California); the non-Calidfrnia XJ700-X models used the 5FZ82 needles.

 

Thanks Len, if anyone knows this stuff I figured it'd be you.

 

The reason I said that the Mikuni rack would work is, when I got my 700n it had a rack of Mikuni's on it. Granted there was a difference in how the throttle cable was attached, but the rack did fit. However the Mikuni's were 32mm instead of the 33mm. All that being said, I like the setup that I have now better and I wish you well with whatever you decide to put on it. :wink: