• Enter the March CB750 Supply gift certificate giveaway! It's easy... Click here, post something, and you're entered into the drawing!

Just curious .. . WTF is This!!??

Pawl

CB750 Enthusiast
Messages
39
Reaction score
1
Points
6
Location
Yellowknife, Northwest Territories, Canada
I was taking my carbs off last year when I got my 1st CB, and I saw This shit cast into the cases? (just ahead of the swingarm pivot, on the throttle side) At first I thought it was some place to hold some bolts you might take off the carbs when you remove them, which is what I was doing at the time! . . . and then I thought "How considerate!". . . Then I thought . . .Naaaaaaaaaah! . . . gotta be there for some other reason? .. . and I so far haven't come up with one.
Anyone got any ideas?

IMG_2040B.jpg


IMG_2041B.jpg
 
Last edited:
hahahahahhahahahahahah did the same thing last night ,asked myself the same question Pawl .Anyone???????
 

Attachments

  • Nearly done.jpg
    Nearly done.jpg
    305.6 KB · Views: 417
  • Nearly done2.jpg
    Nearly done2.jpg
    303.3 KB · Views: 366
  • New exhaust.jpg
    New exhaust.jpg
    247.1 KB · Views: 300
  • Super Sport before.jpg
    Super Sport before.jpg
    261.4 KB · Views: 339
Hmmm.. :umm: You got me! Now I'm curious too. It's just too weird to be there and not have a purpose.
 
I don't think they even know! That's why they put Y4 right above them.

Both of my 450 engines have them also. Although only 2 instead of 4. Die casting is a black art. Who knows why. Maybe to locate them in trim die or some other secondary op. The orientations look kind of random though, like they just tightened a bolt into a hole.
 
And here's the 450. I know! It's one for each carb! :)
DSC01026.jpg
 

Attachments

  • 1907379_10152534731955775_1090377408261647465_n.jpg
    1907379_10152534731955775_1090377408261647465_n.jpg
    90.4 KB · Views: 295
It has to be something to do with the casting process. The one on Travis's 75 looks like it has a gate vestige sticking up. It may be a provision for a gate to an overflow in the die. These are used to remove the hot gases and impure material from the die when casting. If it was later determined the overflow was not needed, they could unscrew the gate to the overflow and shut it off with a standard bolt. That would explain why there are more on larger castings also. More material, more hot gases and impurities to evacuate. Just a guess.
 
I found some similar casting marks on the bottom of a CB750 engine. The hexagons have numbers in them. :shrug:
 
Still no idea on this? There is a couple of these markings on the bottom of my case as well - and yes, it certainly looks like a bird on my case as well.
 
Maybe its a game the japs are playing on us silly Americans to see how many of us will rummage around their toolboxes seeing if we find anything to fit it lol
 
still flogging this dead horse ,er......bird lol. Havent been on here in ages ! who rode the snot out of their bikes this summer ?
 
Back
Top