Engine differences?

[Guest]

Hi All
Some advice please. I have a 1979 GS 850 and a spare engine for it with a damaged head. There is a stripped 1981 engine on eBay which might go for the right price!! What differences are there between the '79 engine and '81 engine, obviously mine have the VM carbs and a kickstart. Will the manifolds for the VM's fit the later head? Any differences elsewhere in the engine?
Many thanks
Colin

[Nessism]

Don't think the manifolds interchange. There are various other differences most noteworthy are the ignition and kick start.

[bwringer]

The cylinder heads are different, as well as the intake boots, airbox, and carbs (and obviously the '79 has the kickstart stuff). However, they will interchange -- you could put a '79 cylinder head on a later model bottom end and vice-versa.

'79 comes stock with points, later models have electronic ignitions. The throttle and I think choke cables are a bit different because of the different carbs.

So no, you couldn't put the '81 head onto the '79 engine and use it in your bike unless you also had the '81 carbs, boots, and airbox (and throttle cable, and choke cable, and ignition).

[The Artful Bodger]

Thanks for the replies fellas. Guess I'll give this one a miss, I like the VM carbs and want to stick with them. I possibly can repair my spare head, the PO snapped three exhaust bolts then drilled each of them off centre. One is still in the head so might come out with a nut welded to it, the other two................... I've never seen drilling out quite like them! More of the alli is gone away from the bolt holes than the original holes, he's got the broken bits out but it's now got some very eccentric holes left.
I'll have a go at filling them with weld and re-drilling them, got nothing to loose since at present the head's scrap. Still I bought the engine and loads of other bits from this guy for a song, if I ever need the engine I can always re-build my existing head and fit that. I'm a sucker for a "bargain" on eBay and this one in bits might be a real bargain, but for someone else not for me.
Colin