1977 KZ1000 Restomod

Even though I haven't sorted out the last of the problems with the 750, I have lined up the next project. I'm not picking the bike up until early December but I wanted to start this thread now so I can decide exactly what I am going to do with the bike and get started straight away. Hopefully the 750 will be sorted before I start

Here is the plan so far:

Engine

• 1135cc Wiseco Pistons
• 38mm inlet valves
• Crankshaft: check and balance (strengthening?)
• WEB-CAM stage 2 cams
• Oil cooler (SETRAB or Earls?)
• Mikuni RS34
• Delkevic Megaphone

Chassis

• Frame bracing
• Swingarm: Zephyr 1100 or K & J (box or neo classic - maybe overkill if keeping the spoked wheels)
• Öhlins S36... shocks
• Zephyr 1100 or ZX9 front end
• Keeping the spokes, but will run 110 front and 160 rear

There will be a few other changes (clip-ons, rearsets etc.) but the above lists are the things that I would like some feedback on. Everything else is down to taste.

I am going with 1135cc and not 1197cc on the recommendation of the guys doing the work for me and also because at 1135cc it will still be a lot more power than I am used to. I've never had more than the 102HP of my Hornet and that is only at about 10500 rpm, torque is only 65Nm and practically nothing down low - the 750 pulls way better under 5000rpm. I figure I can always up it to 1197cc down the road without needing to change anything else.

The cams and carbs are solely based on the recommendation of the engine builder. I'm not sure whether to keep the airbox or go with pods (K & N). This is a widely disputed topic so I'll probably flip a coin

I want to stick with the spoked wheels. I figure that a new swingarm, the frame bracing and maybe even USD forks will give the bike enough stability. I have absolutely no experience though, so any input here would be appreciated. Recommendations for a swingarm or new front end would be appreciated as well. There are a few threads on forks which I am working my way through, but I'm looking to minimise the changes (hence I'm considering the Zephyr forks - not as stable but I think I can use the original axle and hub?).

It's probably pretty obvious that I'm still trying to figure all tis out. I started this thread so you guys can keep me on track and make sure I don't plan something that won't work

Anyway, here's some pictures of the bike in its current state:

A couple of things to consider.
Anything over 1105cc requires cylinder boring for O/S liners and the crankcase mouths also need opening to accept the larges spigots.
( The 1105 max overbore should be avoided as it leaves the liner spigots very thin and prone to cracking and increased oil burning )
You can build a very fast reliable 1075 streetable motor for a lot less aggro and money and the power difference from a reduction of 60 cc won't be noticeable.
The Delkevic system uses 33m id headers so a little on the small side for anything other than mild tuning.
Something like a Hindle system at around 38 to 40mm would complement the proposed engine mods to get the most out of them.
The air box is one of the biggest power killers on tuned engines so it needs at least some mods for increased flow .
Crank will need indexing and welding.
I'd go 37 inlet - 33 exhaust with a good port job and around 410 lift cams.
Use the 1mm shorter J /GPZ type valves to get the correct seated valve to valve clearance without having to tip the stems to achieve maximum valve lash.
Done correctly this will easily give you a strong 160 mph motor that will pull strong from idle.

Thanks. I was aware that the crankcase mouths would need opening and I'd need new liners. I did consider the 1075 but as this project is going to cost a fair bit I decided that I would rather take more time to finish it than compromise on parts/mods. Having said that if the difference is negligible I could almost get the Ohlins shocks for the difference in price. Do you have any numbers/curves showing the difference between 1075 and 1135. I realise it depends on the rest of the work done - porting, valve size etc. - as well as carbs, airflow etc. but it would be nice to have something to compare.
I waiting on a quote from the guys doing the work so I'll see what the price difference is between 1075 and 1135. Will post back when I have some numbers.

Thanks for the tip on the Delkevic, I hadn't thought of the header size! Will look into the Hindle systems and maybe revisit the Kerker. Sounds like it may also be better to just go for the K & N pods and get in touch with you regarding air jets.
I'll check the lift on the cams the guys recommended.
38mm inlet valves were recommended to me, would 37mm make a lot of difference? Does this still apply if I just go for 1075cc?
I'll see what valves they recommend and post back. They did say I should switch to shims under the lifters - are they stock on the J/GPZ models?

Thanks for the info/advice!

Checked the cams.
They recommended the .395/.395 combination listed here: webcamshafts.com/pages_vehicles/motorcycle/kawasaki/1730.html

They did say that I should lower the lifters (lower shims/shorter valves).

The RS carbs are completely different from the stock ones, so the air corrector jets are not applicable.
With those cams, shim on top is fine. Most recommendations I have seen suggest that shim under bucket is needed on cams with more than .410 lift.
Since there are so many variables involved, and because engine building is at least as much art as science, you will get some strong, opposing viewpoints on most everything. We used to have some real humdinger discussions around here.
Zed1015 and his crew have built a fair few of these engines, maybe your builder has, too. At the end of the day, it is your money and your ride. Keep in mind a realistic view of how you will ride it. A really wild engine sounds like so much fun, until you get into a bunch of city traffic, and the thing is lurching, bucking and overheating.
It looks like you have two good options that I bet each builder will defend furiously.
Good luck.

On the market we have used big bore kits all the time. They neglect to add that they're prone to overheating and not suited for normal street riding. When asked they pull their ads or try to deny it. That's when the DOG PILE begins. :evil: :woohoo:
Be a shame to spend all that money only to ride it for short times and the rest just looking at it. :whistle:
Steve

TexasKZ wrote: The RS carbs are completely different from the stock ones, so the air corrector jets are not applicable.
With those cams, shim on top is fine. Most recommendations I have seen suggest that shim under bucket is needed on cams with more than .410 lift.
Since there are so many variables involved, and because engine building is at least as much art as science, you will get some strong, opposing viewpoints on most everything. We used to have some real humdinger discussions around here.
Zed1015 and his crew have built a fair few of these engines, maybe your builder has, too. At the end of the day, it is your money and your ride. Keep in mind a realistic view of how you will ride it. A really wild engine sounds like so much fun, until you get into a bunch of city traffic, and the thing is lurching, bucking and overheating.
It looks like you have two good options that I bet each builder will defend furiously.
Good luck.

Thanks, that's sort of how I figured it would be. A lot of the decisions will be deferred to the builder as he will also be doing the MOT (not an easy thing for any non-standard bikes over here). I really just want to be as informed as possible so I can maybe steer him in one direction or the other. He definitely has built a few KZ's.

As far as being stuck in traffic, that wont be a problem. The hornet and the 750 are for commuting/daily riding. This thing will only come out on summer weekends or the occasional track day.

Thanks for the info on the cams/shims and carbs. I remembered seeing a lot of posts on the air corrector jets, guess I got mixed up on which carbs they were for. I'll see what the builder recommends for valves, springs and shim/lifter setup. If it's not over the top I'll just do what he says - he has to sign his name on the MOT paperwork

I guess I need to start searching out those old threads to learn a bit more about all this...

SWest wrote: On the market we have used big bore kits all the time. They neglect to add that they're prone to overheating and not suited for normal street riding. When asked they pull their ads or try to deny it. That's when the DOG PILE begins. :evil: :woohoo:
Be a shame to spend all that money only to ride it for short times and the rest just looking at it. :whistle:
Steve

I talked to the builder about this. The big bore* kits they have start at 1229cc and are only really for track use. They would be way over the top for my purposes (I'm pretty sure the 1197cc would be too). He said that experience has shown the 1075 and 1135 to be the best options and that both definitely need a good oil cooler.
You're right though, I don't want to just look at it But being a weekend bike I should be alright as far as overheating is concerned. My usual weekend trips have hardly any traffic lights or stop signs

* EDIT: Sorry, mixed up big block and big bore kits

All i can say is bigger isn't always better and faster on paper isn't always faster on the street.
My turbo is FAST but i can run rings around it on the twisties with normally aspirated.
Too much of the wrong kind of power will only be of any use in a straight line and all your mates on "slower" bikes will get home before you.
Been there, done that and those bikes spent more time garaged because they were a pain to ride.
There's a reason why 1075 is probably the most popular size and all of mine are at that capacity for reasons of both reliability and performance.
Shops mostly just want to sell you parts and take your money regardless of whether the result is really suited to your needs so you should get a ride on a sorted 1075 to see what you get before you pull the trigger, you will be pleasantly surprised.
My daily Z1R runs pretty much the spec i suggested with 1075 Wiseco's ,1mm o/s valves, Manzano ported head , stock cams, 32mm mikunis , 4-1 pipe, Dyna 'S' and it just goes and goes.
I've been running it 20 years without a glitch, it'll happily see the other side of 160 mph if needed , return over 50 mpg at steady motorway speeds and best of all it just makes smile every time i ride it.

Thanks Zed. The fact that the guys I'm dealing wit recommended 1075 or 1135 makes me think that they're not just out to make as much cash as possible. So far they haven't favoured the 1135 - that was all me
I always figured 1075 was the most popular size as the step up to 1135 meant a spending a lot more money.

It may be a better idea just to go with the 1075. With a well ported head and bigger valves it should be fine going by your experience. The important thing for me would be knowing that I *could* upgrade by just replacing the pistons and sleeves and getting the crankcase opened up a bit (not requiring any new work to be done on the head or crank). That would mean that I would have only spent extra money on the pistons. This would also leave it open to just running it for a couple of seasons and then deciding if I needed to mess with it.
You said you run stock cams and 32mm carbs. The cams can always be swapped out later, but I will definitely be getting new carbs. Would the RS34's also be OK with your setup?
The Dyna S is also on the list

This is a great post, just what I was looking for also. I was planning on a 1197 kit on the 77 LTD resto build. I read an article by Larry cavanaugh about that size build being very reliable street motor with the correct parts. He never mentioned overheating throughout the entire article. Here is a copy and paste of one paragraph from the article

“For a street motor up to 1197cc, the KZ head [if you already have one or if you already have KZ pistons] is the right one. You can make a great 1197cc street motor with a KZ head using GPz11 Intake Valves with the correct cams to create a motor that makes great torque, idles well and behaves very well in
stop and go traffic. In fact, it would serve as an excellent touring type motor or a killer / sleeper cruiser motor [LTD].”

Here is the link to the entire article
www.kz-1000.net/post/130285291257/faq-ab...kz900-kz1000-engines

I have already bought a set of cases bored out for a 1197 spigot that has all APE studs and crank stiffer plate. I have a spare cylinder and picked up a set of 1197 LA Sleeves. I was planning to us a set of Norris 407 cams. That’s about as far as I have got with parts acquisition. I also picked up a complete cylinder bored with pistons at 1135.

I’m going to really do my research before I go any further.

Thanks for the link. Feel free to fill this tread up with anything you find I'll also be trying to get collect as much first hand info as possible before I pick up the bike.

The first thing I'll be doing when I get it is getting the engine cases vapor honed and sending the crank off to get welded and balanced. Then I need to decide if the crankcase mouths need opening up or not...