FJD

+2 on this subject, the bigger hole will be difficult to keep tight

I had these headers on my Yamaha, and they were absolutely great, and gave very good power too

I would try to get it running first - rusty valve seats maybe

There is no need to only have two S's.....i have three of them.

Just bought a set of new 78 mm MTC pistons intended for a kwaker GPZ - they have 17mm pins, i will get them machined to 18 mm to fit the GS

the GS 1000 here is a 2-valve head

So block arrived, must be 78.0 bores as my dials show, will get them measuted more accurate and start finding some pistons and rings. Anyone has some Wiseco, MTC or JE part numbers i can feed google with ?

Made in USA does not neccessary mean a good thing all the time, i know that too. Engineering wise, i rather trust manufactureres from this side of the pond as well.

Hi folks, what´s the biggest bore you can do on a GS1000 engine ? Reason for my question: Seems like i have bought a block bored out to 78.5mm -- but without pistons. Seller claims they fit cases without modifications, i will need to find suitable pistons and rings though Anyone knows what pin size are stock GS rods - and can they handle pistons that size ?

I would weld

ahh - seen that too, oil pump blown apart. whole engine rebuild time then....

I boght mine from Talon. But was Aluminium

+1 My words....

Yes my uncle has the same problem with APE at the moment....

just run a spacer plate under the block