Xj900 31a vs xj900 58l (seca)

I've been gone for sometime, but am back to the world of xj's!

I picked up an xj900 seca a few years back .it looks like shit. No worries, it was 300$. It turned over. It runs (sort of...nother story nother time)

I need a gas tank (big surprise, right?)

I found a dude that says he can line mine and it'll be good as new. I call bunk. 40% of the tank is missing. Easily.

I found one for sale in Switzerland for like 400$ delivered. I don't wanna spend that much. Yet. I did find one from a 1985 xj900f 58l. It looks the same. I can't find anything that says it won't work. According to Wikipedia (most trusted source on the internet) they are identical body/frame wise. Is this true? Or does anybody have a good tank laying around for a 1983?

Unless I can be pointed in a better direction.....I plan to keep the bike as stock as possible. And ride it back into the ground.

Thanks!

 

I should take a picture with the light coming through the holes....it'd make Jackson pollack hard

 

If you look up the parts on a fiche diagram, if the first 8 numbers of the PN are the same it will fit.
Otherwise, it may need some modding or not fit all together.

 

I'll do just that!

BTW, what do the first 8numbers denote?

Thanks!

Josh

 

JYA- JAPAN, Yamaha, motorcycle
35H (example)- MODEL, etc...

See the following:

https://xjbikes.com/forums/threads/tech-topic-model-id-and-vins.14577/

 

I checked...it's a no go. Asked the seller and he said too different...gotta keep checking

 

Yeah I cross checked all of that.

And while the tanks look really close, I can't take the chance

 

Old thread, but for future—- my bet is that the tanks are interchangeable.
I wish I had one here to do a swap for the tank swap Column. If anyone had definitive proof, please let me know.

also, if anyone had a rusted-out or damaged Xj900f tank, I’d Possibly be interested in getting it for tests (I’m in NY, so shipping from Europe may be a damper).
DFox

 

Well, kinda-sorta, but for the most part correct.

For part numbers that are in this format:

123-ABCDE-45-FG (btw, any of the positions could have been populated by letters or numbers)

the "123" is the model ID code that the part was first used on or designed for. So a part number that begins with 4H7, for example, was first used on / designed for the 1980-81 XJ650 Maxim models (which used model ID code 4H7). And the same part may have also been used on a whole series of other bikes...and for many, many years, even getting far outside the "XJ" model line. Exception: universal parts, such as spark plugs and things of that nature.

The 2nd string of characters (ABCDE) is the "parts group".....so for instance all (almost) gas tanks are in parts group 24110, so again in example, a XJ650 Maxim gas tank is 4H7-24110, while a XJ900 Seca tank is 31A-24110, a 750 Seca tank is 5G2-24110, a TT600 tank is 34K-24110, etc.

The 3rd group of characters "45" is (usually) indicative of a revision in the parts design that occurred sometime in the production history of the part. So, for example, if the original XJ650 Maxim gas tank was 4H7-24110-00, then if a change in design was made, the tank would then go under the new part number 4H7-24110-01. And if another revision was made then the part number would become 4H7-24110-02, and then -03 etc. as subsequent changes were made over time. These "design changes" happen for may reasons (supplier changes, functional changes, or the need for fitment changes.....for example, many Yamaha handlebar switches are basically identical, except for their wire harness end connectors....and eventually, many different versions are consolidated under a single "universal-fit" part number, which might be revision #20 or so).

The last string of characters represent any "variables" that apply to the standard part (no matter what revision it may be). So for example, all XJ650 Maxim gas tanks are physically the same tank, but they come in different colors, so we would have this group of part numbers:

4H7-24110-00-6G ("6G" is the color ID code for the New Yamaha Black paint color)
4H7-24110-00-2J ("2J" is the color ID code for the Ruby Red paint color)
4H7-24110-00-H8 ("H8" is the color ID code for the Star Red paint color)
etc.

Other popular codes in this field are: -93, for a chromed piece; -98 for a low-gloss-black painted piece, etc.


Now, there is another group of part numbers that are used for "universal" parts, such as fasteners, etc. and take the form of:

12345-67890-AB

There is a somewhat specific meaning to each grouping of characters, but, since there are so many exceptions to whatever rule exists (mainly because there is an almost infinite number of variations in the type of hardware that exist, as well as other types of non-hardware parts that fall under this type of part numbering scheme), it's not going to be too meaningful to discuss the characteristics in much further detail. As you might imagine, there is a LOT of part number consolidation that occurs in these types of products, and instead of "revision" part numbers, they are just superseded to a common part number...........for example, a standard M6 lock washer in some bikes was black-phosphate coated (92907-06100-00) and the identical size/shape/etc. washer on other bikes was bright zinc-plated (92995-06100-00). Well, at some time, Yamaha decides that they no longer want to offer the black washer, so it's part number (92907-06100-00) supersedes to part number 92995-06100-00....and only the bright zinc-plated version is available (and if you order a 92907-06100-00 black washer, you'll end up getting a 92995-06100-00 bright washer, and it's labelled as such.....with the 92995 part number on the bag).

Now, from the above simple example, we can (maybe) conclude that the 92907 and the 92995 are the "part type" indicator......the both refer to some type of "standard split-ring lock washer".....and you'd be right. Sometimes. Mostly. Good enough for government work, or inventory management work......

-------------------

Now, let's go back to the original question......is a 31A-24110 fuel tank (1983 XJ900RK Seca) interchangeable with a tank from a 1985 XJ900F model (using tank part number 1FW-24110)? Well, maybe, or maybe not. Typically, there will be color differences (which will be designated in the last 2-character field of the full part number, as explained previously), but excepting that difference, will it "fit?....that's what we want to know! Unfortunately there's no way to tell from just the part number......this is something that can only be learned by hands-on experience. It may fit perfectly, exactly interchangeable with only a re-paint to make it "the same" as an original XJ900RK tank, or it may physically fit but need some minor modifications (maybe a different sized petcock was used, or maybe there is an emissions port that needs to be capped off, etc.).

As you can imagine, the "can it (any part you can think of) physically interchange and be used?" is one of the most common and toughest questions to answer, as it requires someone with multiple parts and multiple bikes to attempt the interchange and figure it out. Yamaha engineering could probably answers those questions in a heartbeat, but good luck getting that info out of them..........

Which is why the hogfiddles of the world are so valuable!