gs 1100 motor into gs 1000?

[roadron]

wow! what a great site.i am considering swapping an 1100 into my 78 gs1000 .will it fit airbox and all? is the gas mileage comparable ? thanx ron

[humhead]

Suzuki Lists the same part number for 1000 & 1100 Chain drive frames from 78 to 83.
Fuel mileage should be similar ~40mpg.
You'll need the carbs & airbox from the 1100.
You'll need to keep the ignition from the 1000. (This would be the time to upgrade to a Dyna S, if you haven't already.)
Use an 1100 exhaust.

Terry

[rphillips]

The motor mount, on the left side bottom, will not fit. You can fabricate a new mount, or relocate the studs on the frame. There is a small issue with the front motor mounts, You may need the mounts from the GS 1100. The petcock on the "78" 1000 tank will hit the top of the CV carbs on the GS 1100 engine. You can fabricate riser to lift the rear of the tank apprx. 5/8" and it's hardly noticable. The "80" model petcocks are smaller & may fix this little problem. A 4 into 1 pipe from an 1100 will fit, only if you cut out a small, apprx. 4" section of the frame, that only supports the rear foot peg, as the 1100 pipe fits too far up under the frame, not near as big of a deal as it sounds. A GS 1000 pipe on a GS 1100 will fit, but the pipe sits apprx. 4" outside the frame, at the rear mount, I would think the GS 1000 exaust should be a better fit. A buddy of mine figured out the GS 1100 electronic ign. wireing, he installed one wire, (I don't have a clue where or what it connected to), on my "78" GS 1000 wireing harness, and the GS 1100 ign worked perfectly. I don't remember any other issues, but that's been about 23 years ago

[roadron]

this is all VERY helpful. thanx guys. my gs 1000 has the dyna S. will it fit on the 1100? i thought the later petcocks had a different bolt pattern.

[humhead]

The Dyna S should fit (Dyna lists the same part number for both engines). Using the 80 or newer ignition means swapping coils & the possibility of the igniter unit crapping out. (very expensive to replace.) The Dyna S doesn't use the igniter.
The 1980 1000E & S tank uses the smaller petcock, which has a different bolt pattern. This should solve the clearance issue. Unfortunately, Suzuki only made this particular tank in 1980. They do turn up on ebay from time to time.
I wound up with two of them.....I wasn't even trying to get that specific tank.


Terry

[roadron]

what about the tach? mine is mechanical.

[humhead]

1100s use a mechanical tach. The tach cable threads into the valve cover on an 1100. The 1000 cable threads into the cylinder head. You may have to change cables, that's all.

[roadron]

muchos gracias guys .that covers it for me.