gs750 engine mount compatibility

[Racing Geek]

The engine mounts I'm concerned about are the ones on the bottom and the one in the back on the bottom. Were the engine mounts the same for the early two valve air cooled 750's to the later 4 valve air cooled engines?

What about the 1000, 1100, 650, 550, etc?

[TheCafeKid]

The engine mounts I'm concerned about are the ones on the bottom and the one in the back on the bottom. Were the engine mounts the same for the early two valve air cooled 750's to the later 4 valve air cooled engines?

What about the 1000, 1100, 650, 550, etc?

No. For starters, the early 8v 750s were a bit longer overall because of the kicker gear set up. Obviously the 16v didn't have that. Nor did the 1000, 1100. The 79-81 850 had similar dimensions as it originally had a kicker in 79, but was removed and the spot for it was just blanked out in the cases. But that's a shaft drive which had a whole different frame.

Now, there are plates/adapters that allow swaps for instance the 7/11 swap, and I've read that an 1100 16v motor will bolt into a 1000E frame and vice verse but I've not seen it first hand to know what's involved.

But, with the larger displacement chain drive bikes, with some fabrication work to make new mount plates, I think any one of them would be "swappable". What exactly are you wanting to do?

[tkent02]

I have heard from Ray the 1100 engine fits right in a 1000E frame...
I have put a 1000E engine in an early 750 frame....
I have seen an 1100E engine in a second generation 750 frame...
All of these fit right in, so all of his means a second gen 750 engine fits in an early 750 frame.

[TheCafeKid]

I have heard from Ray the 1100 engine fits right in a 1000E frame...
I have put a 1000E engine in an early 750 frame....
I have seen an 1100E engine in a second generation 750 frame...
All of these fit right in, so all of his means a second gen 750 engine fits in an early 750 frame.

But they're not straight bolt ins though correct? Meaning you have to change mount plates or the like to get the mounts lined up?

[tkent02]

Yes, but the lower part fits tightly into the frame. I had to make four motor mounts to put the 1000 into the 750.

[Racing Geek]

What exactly are you wanting to do?

I have a 16 valve motor that I have setup to go into a CL360 frame but I'm scrapping that idea and I'm going to make a custom frame. My plan was to get a round tube frame and incorporate the bottom part into the frame I'm making. I was hoping someone would know what frames my 16 valve 750cc motor would fit without any modifications. If I have to make any modifications I'll just look for any round tube gs750 frame to use, cut off the old engine mounts, and weld on new ones. More work but whatever.

There is a 1978 gs1000 frame for sale near me that I was thinking about using but if it won't work I'll keep looking.

[Racing Geek]

If it's close and you guys are saying all I have to do is make those triangle shaped mounting brackets out of some flat stock then I'll do that.

I also don't want to use a frame that will let the engine go below the bottom tubes.

[tkent02]

Yep, you may have to do some welding on the front left one.

[Racing Geek]

Why only the front left one?

[tkent02]

The 1000 frame is a bit wider than the 750. The other three mounts were flat pieces of steel, easy stuff. The front left one the mount on the engine lined up with the middle of the frame, so a bent piece was needed to go around the frame. I had no means of bending it perfectly so I welded up a "Y" out of four flat pieces of steel.

[Racing Geek]

Would a different frame (750?) require less modification?

So just to clarify, I should avoid all shaft drive frames because they are totally different?