Gs 400 engine & Gearbox with a Gs450 Head? will that work?

[kris90]

Recently my 1982 Gs450 L seized the left conrod onto the crankshaft. its dead.

Now i have found on eBay an engine from a gs40x so a 400er i could buy tomorrow. in the pictures everything looks absolutely identical to mine, it even has no kickstart like mine. the engine only consists of the crankcase, Gearbox, flywheel... basically everything i need.

Now will my 450cc cylinder, Head, valves ect go straight on? because they are still all fine from my original engine and the new one doesn't come with any.

[peteGS]

Depends... if it's the 4 valve GS400 which we know as the GSX400 over here in Aus, then I believe there are enough differences to make it not work.

If it's the earlier 2 valve GS400 then in theory yes it should work, but I don't know of anyone who has actually done it myself.

[Big Rich]

What about the timing pickup? That's something else I would imagine giving you a headache.

Kris, you shouldn't have too many problems finding a replacement engine. You could even use the bottom end from a GS500E (the GS500F would work too, but has an oil cooler). If you haven't already, head over to the GSResources and look around. Those guys know every nut and bolt on older GS bikes.

[peteGS]

Yep good point Rich... on both matters 

I should've suggested the GSR for sure... 

[EE]

Hey Rich, are you saying you can use a GS450 4 valve head on a GS500 bottom end?

[peteGS]

Yep he is indeed!

I think the gear shift is inverted in the GS500 compared to the 400/425/450 though, but I'm not 100% sure on that.

A common upgrade for the 450's is to bolt the 500 barrels and cylinders on. I think you need to mix and match head gaskets but it's not a particularly complicated swap out.