CALLING ALL 900RK SECA OWNERS!!!

I'm trying to figure something out that should be simple, but it isn't......

It has to do with the front brake system on the 1983 XJ900RK Seca models.

I've come across two different versions of these front brake systems, and was wondering if any of the 900 owners out there could chime in and help me decipher this seeming conundrum of a unclear mystery.........


Version "A" is the style that is pictured in both the Yamaha parts AND service manuals, and has the rubber hose coming off of the master cylinder that leads into a small, kinda round "cylinder" type of brake "union joint". Coming out of this joint is a hard metal line (3-4" long) that goes straight across the bike and into another matching small, round cylinder type of union joint.

Out of each of these two individual union joints goes the individual rubber hoses down to the same-side brake caliper.

So version "A" has a rubber hose out of the master cylinder, going into a small "cylinder" union, a metal line out of that union going into ANOTHER small cylinder union, and then caliper lines coming out of each individual union and running down to the calipers.

Version "B" is the style that is pictured in the Haynes workshop manual for the 900RK......it has the rubber hose coming out of the master cylinder, which goes into a centrally located port on a single, long (6-7") horizontally-mounted "log" style distribution joint, and then each caliper hose comes out of the end of this same, single distribution joint.

So version B is a more "traditional" style of Yamaha brake system, like is found on almost all of the other XJ-series dual-disc bikes.

The Haynes manual, which has a picture of this style system, is based on a European 900RK model. So you would think that solves the question of "the differences", but..........

The person from whom I acquired the "Version B" traditional style front brake line system from has had 3 of the 900 models (he's here in the USA) and says that every one that he's had, has come equipped with this version "B" style system! And I find it highly unlikely that he's just so happended to have acquired 3 different 900 Seca's from Europe.........!!

The person whom I acquired the version "A" system was an eBay seller based in California who was parting out a bike. Remember, the version "A" system is the one that IS pictured in the US Yamaha parts diagrams and factory service manuals...........

So, can I have a show of hands, stating whether your front brake system is the Version A or Version B style, and whether your bike is a US model (serial number begins with JYA35H--) or a Canadian version (serial number begins with JYA31E---) or a Euro version (serial number begins with JYA31A---) or a anywhere-else-but-the-above-versions (serial number begins with JYA33F---) and let me know.


Thanks!

 

Hi,

Interesting question with a arange of interesting answers...

I have a 1985 XJ900F (slightly larger capacity - 891cc - than the '83 US versions).

It has version B - single rubber hose coming from the front master cylinder down to a "log" type distribution housing where the 2 sides then distribute equidistantly via rubber hoses to the brake calipers on each side of the front wheel.

Probably bad in need of replacement hoses BTW.

 

my 83 XJ900RK has the 'A' version.
thx,
baz

 

THanks Baz..........is yours a Canadian version bike?

 

The one I rode to work today has version A and is a US model.

 

Not sure if there was a specific Canadian version. Although, my 83 XJ900RK has a rear master cylinder which a friend in the US with an 83 XJ900 says isn't the same as his. So... makes me wonder if there were slight variations depending on the market. And I have read that the XJ900 was in some ways a parts bin special and during its limited run had a few different suppliers for some parts - perhaps like the front and rear master cylinders...
By the way, Chacal. I still want the manual petcock for the XJ900. Maybe you can tell me what it would cost including shipping to Toronto Canada.
Below is a pic of my XJ900's rear master cylinder.
thx,
baz

 

Mine has the brake system off an 83 750RK and is identical to the original off my 900 which is type A

 

Thanks for the info guys.

Baz I sent you a PM with the info on the petcocks/fuel valves.

 

Only difference is the calipers are slightly different.