Big Bore for KZ750?

Is there such a thing as a "big bore" kit for a KZ750 twin?

No Not really ,, I think the service limit is .060 Before getting to close for comfort ,, But you could always sleave the engine Have custom Pistons made ,,But By then you will be over what the bike is worth ,,

The biggest 750 twin that I am aware of displaced 900+ cc and put 90 hp to the ground. And IIRC, the guy had $4000+ invested in the motor, and a whole lot of time and labor.

steell wrote:

The biggest 750 twin that I am aware of displaced 900+ cc and put 90 hp to the ground. And IIRC, the guy had $4000+ invested in the motor, and a whole lot of time and labor.

90 horses at the rear wheel in a lightweight twin platform musta been a screamer. I'll bet that massaged twin really surprised some of the big fours in a head-to-head match.

Cheers-Colin Firth-Ontario Canada

reborn650 wrote:

steell wrote:

The biggest 750 twin that I am aware of displaced 900+ cc and put 90 hp to the ground. And IIRC, the guy had $4000+ invested in the motor, and a whole lot of time and labor.

90 horses at the rear wheel in a lightweight twin platform musta been a screamer. I'll bet that massaged twin really surprised some of the big fours in a head-to-head match.

Cheers-Colin Firth-Ontario Canada

There were actually two 750 twins that I am aware of that were built to that level, and both were roadraced. After all that time, effort, and money that they invested, I hope they were successful. One was in the US or Canada and the other was in Europe, I might have a pic of the US/Canada one that Steve Darlington (a member here) posted to the GPz mailing list. He knows the guy that built and races it.

A slight correction, the one pictured below is "only" 82 rwhp, but that's close enough for me



Pic provided by Steve Darlington, talk nice to him and he may tell you the details

Post edited by: steell, at: 2007/02/12 23:35

The way I see the 750 twin is its ment to cruise with,not a race bike, I have one and I like it cause it is what it is, a cruiser, if you want a screamer go to a 4cylinder model or maybe a three cylinder two stroke like I did and keep the twin for those nice relaxing rides.

agawam wrote:

The way I see the 750 twin is its ment to cruise with,not a race bike, I have one and I like it cause it is what it is, a cruiser, if you want a screamer go to a 4cylinder model or maybe a three cylinder two stroke like I did and keep the twin for those nice relaxing rides.

Nah, just have two (or more) of them, and keep one somewhere near stock while modifying the other

The 750 twin makes a really nice "get around" bike, in my humble opinion, just the right size, just the right amount of power.

Post edited by: steell, at: 2007/02/12 23:44

steell wrote:

agawam wrote:

The way I see the 750 twin is its ment to cruise with,not a race bike, I have one and I like it cause it is what it is, a cruiser, if you want a screamer go to a 4cylinder model or maybe a three cylinder two stroke like I did and keep the twin for those nice relaxing rides.

Nah, just have two (or more) of them, and keep one somewhere near stock while modifying the other

The 750 twin makes a really nice "get around" bike, in my humble opinion, just the right size, just the right amount of power.<br><br>Post edited by: steell, at: 2007/02/12 23:44

Naaa get three so you can have company on those easy rides and mod one out . But dont expect to win races with against 4 cyl. bikes

Mainly I was just wondering out of sheer curiosity. I don't have a clue what my KZ will do because so far, it doesn't even start. Of course, it has no brakes right now, so starting might not be a good idea anyway.

I wanna know, too. I just bought mine and won't get to pick it up until Saturday. What sort of power should I expect? Everyone keeps telling me that I signed on for more than I can handle. But I seriously doubt that.

Anothersoulx wrote:

... Everyone keeps telling me that I signed on for more than I can handle. But I seriously doubt that.

They have a lot of torque on the low end, that can take you off guard if you aren't expecting it. Great bike, not a screamer but very underappriciated. Put a 17tooth drive sprocket on it and she'll treat you well on the hiway.

Anothersoulx wrote:

I wanna know, too. I just bought mine and won't get to pick it up until Saturday. What sort of power should I expect? Everyone keeps telling me that I signed on for more than I can handle. But I seriously doubt that.

The stock 1979 KZ750 twin comes with 55 BHP. Add good headers and jets and maybe bump that another 10%.

If you are going to want a civilized cruiser, dump the 40T rear sprocket and get a 32T.

It does have good torque and cruises happily in the 2200 - 3000 RPM range.

Mine weighs about 510 lbs as I recall stock.

The best things about it: big and solid, steel tube frame, disc brakes both ends, enough power to go as fast as you need to, reliable.

Post edited by: bountyhunter, at: 2008/02/08 13:35