Cylinder swap, 79 GS750 to a 81 GS850?

[Bobbys 94]

Will the cylinders from a 1981 GS850 bolt up to a 1979 GS 750 engine and head?

[Burque73]

If you search for 750/ 850 swap that brings up plenty of good reading.

Like this thread.https://www.thegsresources.com/_foru...-850-swap-noob

[Grimly]

Will the cylinders from a 1981 GS850 bolt up to a 1979 GS 750 engine and head?

You'd also need the later head as there's an extra bolt at the front, between head and barrels.
That said, it's about the most common engine upgrade done on that era of GSs.

[Nessism]

You'd also need the later head as there's an extra bolt at the front, between head and barrels.
That said, it's about the most common engine upgrade done on that era of GSs.

The extra bolt in the front doesn't seem to be a dealbreaker. There have been lots of members here over the years running mix and match, with bolt, and without, and there doesn't seem to be much repercussions. No doubt, having the extra bolt is good, but there are tons of bikes built before the bolt was added, and they run just fine.

[Steve]

I think the extra bolt did not show up until the '82 850s, and when it did show up, the spacing on the other bolts changed just a bit.

Should be no problem mixing the '79 and '81 parts.

.

[Grimly]

The extra bolt in the front doesn't seem to be a dealbreaker. There have been lots of members here over the years running mix and match, with bolt, and without, and there doesn't seem to be much repercussions. No doubt, having the extra bolt is good, but there are tons of bikes built before the bolt was added, and they run just fine.

Oh well, in that case he can use his original carb set, too. With some minor re-jetting.