TOPIC:

So it's known to me now that the 750 barrels bolt right on to a 650 bottom end, and a 750 valve head would be nice as well but...

The questions are: Straight up power wise it would be best to change to the 750 cylinders and valve head but is the 650's bottom end able to take that increased amount of stress/wear? Secondly is there any point in keeping the 650 bottom end; is a full engine swap just a better idea? Is there any point in installing a whole 750 engine on a 650 frame? Should I just buy a 750?

Much to ponder here, and I know alot of it is subjective and oppinion based but what reasons would motivate a rider to install a 750 top end or a full motor into a 650 frame? It will increase power but are there any other reasons for sticking with the 650 frame or bottom end?

Thoughts?

If your bikes ergos are all set to you, it makes sense to just put in more power, and upgrade brakes and suspension,too, if you get too nuts with the power. That's my eventual plan...it's my bike, I spent alot of time and effort getting it that way...just got attached to it. I'd swap jugs or engines to keep the bike.

If you can find the motor (someone had one for sale listed on the old forum) you may as well swap the whole unit.

I did, but I never rode the 650 so I couldnt tell a big power difference, I only did it because I could. The most difficult part for me was wiring, but I was wiring the whole bike at the time. Im going to rerewire it this winter and make a diagram of the whole harness this time around.

Yea, I'd expect you could get attatched to the bike that houses the motor, the thing is I havn't even ridden once on this bike yet and I'm already getting ideas about such a big swap.

I'm always looking for more power/go, but I'll have to get used to riding the 650 stock before I REALLY want to put that 750 in.
I was just wondering if a 650 with a 750 engine in it has any advantage over a normal 750...

I'm just getting work done on the 650's valve head right now so I probably wont want to switch it out TOO soon after I just dropped somewhere in the range of 150-175 dollars getting the valves ground.

I'll ride it first, but then I may be liable to hot-rod it after!

I think the 650 has a shorter wheelbase, and is a little lighter, than a 750. I know it is shorter than a 83 GPz750 because I compared them

So a bit more nimble maybe?

I have no real experience riding/racing so it's all greek to me.

Personally, my input would be that for a couple hundred dollars you can find a good whole 750 engine to bolt right into the 650 frame, seems way simpler than all that jug work. That is what I am in the process of doing. Total net cost for a great EBay 750 engine after shipping and then selling my 650 engine back to another person, was only about $100 bucks.

Then you can go for the 810 bore kit on top of that, or better still - buy a KZ1000!

There are lots of small differences between model years. Usually getting bigger and heavier. An early model 650 handles extremely well for the era, and the bottom end is extremely stout. It's basically unchanged in the 750 turbo which makes close to 110hp.

The bottom end of my engine has never been apart. The bike makes 80HP and I've had little issues with it. My only issues are a little oil leakage at the base of the cylinder block due to the high RPMs my bike sees regularly.

A full 750 motor in the 650 frame would give a nice performance boost and maintain the low weight\nice handling of the early 650.

Alternatively, a wiseco equipped 650 with cams can be alot of fun to play with. My bike screams in the top end coming on the pipe at 7,000rpm and then I usually shift at 11,000. That old inline 4 running through a megaphone exhaust sounds like nothing else. The fact that it easily bevels the foot pegs on both sides makes it that much more fun.

So either way, building your 650 motor up, or putting a 750 in your frame, you'll wind up with a cool scooter that is alot of fun to ride.

Nicely done dan, sounds like you landed yourself a fine deal, I don't think I'm ready for a KZ1 yet though.

You mention the older 650s though, and mine is an 82 (CSR series), did the handling/durability improve or decline with the newer models. That dedicated KZ site said the CSR engines were toned down a couple HP too (don't ask me how), which is why I'm trying to make up for any anticipated short comings before I'm even riding I suppose

Edit: Skul that is almost 20hp over stock, what's that drive like?

Post edited by: nfswift, at: 2005/10/12 21:16

Not sure about HP drops, but if it's true it might be tightened emissions regulations.

nfswift wrote:

So it's known to me now that the 750 barrels bolt right on to a 650 bottom end, and a 750 valve head would be nice as well but...

The questions are: Straight up power wise it would be best to change to the 750 cylinders and valve head but is the 650's bottom end able to take that increased amount of stress/wear? Secondly is there any point in keeping the 650 bottom end; is a full engine swap just a better idea? Is there any point in installing a whole 750 engine on a 650 frame? Should I just buy a 750?

Much to ponder here, and I know alot of it is subjective and oppinion based but what reasons would motivate a rider to install a 750 top end or a full motor into a 650 frame? It will increase power but are there any other reasons for sticking with the 650 frame or bottom end?

Here we go, the filebase is coming in handy already. Go to community, filebase, then either popular or the 1980 categories. You're looking for the KZ 750 E1 Cycle Guide article. This article discusses many of your issues/concerns.

Thoughts?

Lovely, let's try this again. Many/most of your questions will be answered by checking out an article in the file base. Go community, filebase, then popular or the 1980 category. You are looking for the KZ 750 E1 article that someone kindly uploaded for us. There's some dandy info in there for you.