Gs 750/850/1000 head swaps

[Hank]

Hi all, while trying to find a good head from the 6 iv got i tried a 1000 slide carb head on an 850 as iv read on a forum the stud holes are wrong but it slides on, tho i didnt have any barrels on at the time, but checking the cam chain on cms they all seem the same so does anybody know any other reason they carnt be put on a 7 or 850

[johnr]

i wonder if th slide carb head you have is off a gs1000g which is based o the 850g as theyre both shaftys. i recall years ago helping a mate with a 1000g swap a leaky base gasket and the one we were sent didnt fit, we were later told it was from a chain drive 1000.
i guess the man to ask is @wraith as he has much more experience building shafty gs bikes and he knows what will swap and what wont.

[Hank]

Its off a chain drive as its off my bike but its damaged, iv a gs1100 head n barrels that fits the 1000 too, i tried the 1000 head on 850 barrels today n it seems to fit, no doubt all will be apparent when i try to build one up

[gs7_11]

32 minutes ago, johnr said:

i wonder if th slide carb head you have is off a gs1000g which is based o the 850g as theyre both shaftys.

There were no slide carb GS1000G's. They all had CV carbs.

[wraith]

All the gs850 I've played with had a different stud lay out to the 1000/1100 shaft or chain, the gs850 barrels and head will fit the gs750 but the 1000 won't fit the 850 bottom end, so what you have I'm not sure unless it's some odd ball i have never came across.

If I remember the 850 had a shorter stroke to the 1000 as well but I'd have get my books out and check that one for you tomorrow 

All the gs1000 top ends are interchangeable wether it's a shaft drive a slide carb or CV top end. 

Ps the gs1100g has the D type ports and are the best for tuning  and the gs850 carbs won't easley fit the 1000 head as the ports are spaced different.

The gs750/850/1000 cams are interchangeable the 850 are good for torque, 750 are good for quick rpm and the 1000 are a good all rounder.

Edited September 29, 2018 by wraith
Add a bit

[Hank]

Mmm cheers for the info, iv taken the head off the 1000 chain drive and slid it onto the 850 and the studds were ok, iv a gs1100 barrels and cv  head which im probably puttin g on the 1000 to then use bandit carbs, iv 750,850, 1000, and 1100 engines here so will have a play n see just what will fit on what, iv just picked up a head stamped s4 today so i think iv 4,5 6,7,8 now so will check and post the findings, i know the 1000 pistons have bigger pins so thats a no no swap to the smaller engines