GS1000-GS850 - Do they share the same head?

[ohtwmisi]

Hi everybody,
I am planning to rebuild my GS850(1980 model) and while searching for parts and possible mods, I came up with some questions.
Some of them is about cylinder heads (since mine has suffered a lot)
-So, do GS850 - GS1000 share the exact same head or there are minor differences?
-Do they have the same camshafts?
-What about the valves? Are they the same size on both models?
-Is there any difference in the size and shape of the dome of the combustion chamber? (I doubt that but just to make sure)
Any help would be much appreciated guys - thanks

[Nessism]

The heads are different for sure, not sure if they will interchange. 850 valve sizes are smaller among other things. The camshafts are the same between the early year 850 and 1000 (I have a couple sets of spare camshafts so let me know if you need any).

A few things to keep in mind, the '79 850 and '78 & '79 1000 use VM carbs, and the cylinder head has smaller intake ports to match the carbs compared to '80 and onward cylinder heads. Following that logic, you need a CV carb head - '80 - '83 GS850 here in the US. Suzuki changed the cam timing in '80 for the 850 to add a smig more low end power. I don't think this is overly important but something to keep in mind if you compare different part numbers. And speaking of that, you might want to go to Alpha Sports or similar and look over the parts manual. Comparing part numbers is a good way to determine what parts interchange between models.

Good luck.

[focus frenzy]

the 850 uses that odd idler gear right between the cams, the 1000 head doesn't even have the spot where that goes, the 1000 uses a slipper block. factor in possible deck hight differences and possibly sprocket size differences, the cam chain will most likely not work.

[ohtwmisi]

Thanks a lot - I should really check the part numbers - as for the camshafts I live in Europe, so....thanks anyhow. when I strip down the engine I 'll also measure valves, cams, lobes, etc...

[nisom512]

Thanks a lot - I should really check the part numbers - as for the camshafts I live in Europe, so....thanks anyhow. when I strip down the engine I 'll also measure valves, cams, lobes, etc...

it sounds like it would be a lot of work maybe potential gains if you could ever pull it off. but from the previous posts I would say just get another 850 that runs