This bolt perplexes me

[RustyTank]

Howdy folks. I own a 1979 GS850G. Recently, while pokin around the engine I noticed this bolt underneath the 'secondary gear oil level' bolt, pic attached. I was under the impression it was a crankcase bolt but looked in my manual cause I was curious. Manual says that all crankcase bolts are 6mm and 8mm, but this bolt is 12mm. Also, there are two other 12mm bolts underneath the left side crankcase cover...so what gives? I can't find these bolts identification anywhere in my manual. Will you please help me identify?

[GregT]

It's a crankcase bolt. When the manual says 6 and 8mm bolts it's referring to the thread size - not the head size.
Typically high tensile 8mm bolts used in case applications have 12mm heads. The 6's will have 10mm heads.

[Brendan W]

This might help?

https://www.cmsnl.com/suzuki-gs850g-1981-x-e01-e02-e04-e17-e18-e21-e22-e24-e25-e26-e34-e39_model13500/partslist/FIG-04.html

[RustyTank]

It's a crankcase bolt. When the manual says 6 and 8mm bolts it's referring to the thread size - not the head size.
Typically high tensile 8mm bolts used in case applications have 12mm heads. The 6's will have 10mm heads.

Excellent info! Thanks Greg

[RustyTank]

This might help?
https://www.cmsnl.com/suzuki-gs850g-...st/FIG-04.html

I do love a good parts fiche, always helpful. Thanks Brendan