Cylinder Head

[knotzilla]

Are a 1979 gs850 head interchangeable with a 1980. I know the carbs are different for one thing, Thanks Ted

[focus frenzy]

it is compatable but will require you use carbs for a 1980 850 as the intake ports are larger and the 79 carbs will be to small to get a good seal on the boots.

it is a good sound performance improvement.

[knotzilla]

I should clarify that I have a 1980 850 and I will be using the original CV carbs and intake manifolds. Are the rubber intake manifolds that bolt to the cylinder head the same for 1979 and 1980? I'm more concerned if the bolt hole patterns the same. Thanks Ted

[focus frenzy]

well I am not absolutely without a doubt sure but on the 1000G the pattern is different.
the ports are larger so the 79 intake manifolds will not mate correctly.

[bwringer]

I should clarify that I have a 1980 850 and I will be using the original CV carbs and intake manifolds. Are the rubber intake manifolds that bolt to the cylinder head the same for 1979 and 1980? I'm more concerned if the bolt hole patterns the same. Thanks Ted

No, they are different. The 1980+ boots are larger in diameter, and the cylinder head intake tracts are a different shape. You can't just bolt 1980+ boots onto a 1979 head.

From the head gasket down, everything is compatible (not identical), but the cylinder heads are different enough that they are physically incompatible unless you also obtain the matching 1979 carbs, airbox, and the push-pull throttle.

I'm also fairly certain that the valves and cams are different on 1979 GS850 engines.

[knotzilla]

Thanks for the answer to the question. I also should have asked at the same time if a 81 and 82 head is the same as a 80 head. Ted