Right so i have a 2000 gs500e. I have a few mods on it.
Anyway, i saw on here a mention of the kz 750 twin as a swap and it planted the seed. My question is would it realistically possible. Yes i know anything is possible given enough money time etc. But would it be an more difficult than say, a gr650 swap?

Realistically possible??

How different are the engine mounts and can they be modded without compromising frame strength and rigidity?
How far out will the sprocket alignment be and can the ratio and chain pitch be made to match?
Will the headers clear the down tubes?
Will the cam covers clear the spine
Are the electrical systems compatible?
Is there room for the carbs and air filters?
Can it be done without significantly affecting the CofG

If you can overcome those (and probably several other) potential issues the answer is......... yes.

So can you?

Without the engine i have no idea. Dont know if i could risk spending the £500 to get a good working engine and the answer be a no. Just wondered if anyone had already done it even though i couldnt find anything about it

do you have basic fab tools. Multimeter, Grinder, a decent mig welder, tubing bender, the understanding on how to create engine mounts access to raw materials like tubing and flat stock? the ability to combine these things to actually create something? the GS frame is very forgiving in its design. the lower half of the frontal frame is its own piece.. in theory you could just re-create that part from scratch to get an engine to fit.

Quote from: Alehh91 on January 27, 2016, 09:46:37 AM
Right so i have a 2000 gs500e. I have a few mods on it.
Anyway, i saw on here a mention of the kz 750 twin as a swap and it planted the seed. My question is would it realistically possible. Yes i know anything is possible given enough money time etc. But would it be an more difficult than say, a gr650 swap?

As a general rule, if you're asking this question it means that you don't have the skills/tools to do the job.
I know that sounds harsh, but I don't really mean it that way. It's just that there are several obvious challenges to a swap like that, and someone with the skills and tools would be asking different questions.
Also, I'd be very surprised if that old KZ750 motor made any more power than the GS500 motor, and it's undoubtedly heavier.
So there's no rational reason to go to all the trouble. 

This would really be the first big project id have attempted. So id really jus be winging it. Maybe i should start with something a little simpler haha.

You never know until you try! "To boldly go where no one has gone before...."

If you take this project on, make sure to take your time and snap lots of pics for us 

Generally i aquire tools as and when i need them. Then biggest worry for me would be the electrics. And no i don't have the skills necesary but i would aquire these too as i work on. But there is the very real possibility i would be overwhelmed and give up.
And Rich you would be right as it seems to only make about 10hp more than the gs but torque is up 50% not worried about top end its how you get there
It may not seem like an ideal swap but it deffinitely would be different.

Quote from: Alehh91 on January 29, 2016, 02:28:26 PM
Generally i aquire tools as and when i need them. Then biggest worry for me would be the electrics. And no i don't have the skills necesary but i would aquire these too as i work on. But there is the very real possibility i would be overwhelmed and give up.
And Rich you would be right as it seems to only make about 10hp more than the gs but torque is up 50% not worried about top end its how you get there
It may not seem like an ideal swap but it deffinitely would be different.

I'd be most worried about it physically fitting, and about how much ground clearance you'd have. I'm betting that motor is a lot taller. The electrics should be easy by comparison.

Agreed 

Just looking at one on google images, its huge in comparison, furthermore the exhaust ports are angled and the starter looks to be at the front of the cylinders. It would need a lot of frame mods. Not an easy one, even for someone experienced.

I read a lot of reviews on older bikes. I've never seen one that praised the KZ 750. Instead, they say in order to get a 180 degree crank they had to use two counterbalancers. This made the motor complex and heavy. Without having measured it, the KZ looks large, while the GS motors, whether they be the 500 or 650 show an effort to minimize weight and size. The GS engines are very reliable and parts are available (less so with the 650) whereas parts for the KZ might be tough. The didn't sell many. Then there is the problem of having to explain to GS lovers why you did it in the first place. I would just say, "because it was there."