KZ 650 E ( E Stands for Extra!!!)

Hi everyone. This is the kz650 I had shipped in from WA. It has been turned onto a cafe racer of sorts, and has a temporary engine in it. The stock 1980 motor has cracked head, and is currently sitting on my workbench. I have never actually done a high performance build up on a 4 cylinder Kaw before. I just got the bike running on today, a went through the carbs and adjusted the ignition and hith the starter and BLAMO... it was tearing up rubber down the street! So I figure while I am overhauling the original motor I can still have some fun

The bike needs some serious wiring work, and a new harness.
Also I have a gauge cluster and headlight I am going to put on it. I haven't made up my mind if I will install a rear fender or not. But I have decided to take off the clip-on handle bars and put some euro style bars on. other than that I will eventually give the bike a good paint job and dress it up a bit.

The original engine is gonne get some lovin' By that I mean Wiseco pisons and a rebuilt head. I have a resonable shop in town that can do the valve job and bore the cylinders, but I still need to track down a head.

I have some questions for those of you with some experience with these old 4's. At 30,000 miles should I even cosider the lower end. Are the mains and rods in need of inspection? What else should I consider when I tear down the motor? Obviously the clutch, but what about the cam chain or the primary chain? Really what I am asking is what whould be the norm for a 650 with 30k on it?


By t_f_b , shot with Canon PowerShot SD400 at 2008-05-18


By t_f_b , shot with Canon PowerShot SD400 at 2008-05-18

Looks like a good base for your project. Keep us posted on the progress.

Well I have done a bit of work to it. New bars, new controls and cables, a headlight, and a rear fender. I tore the top end of this engine down and found it had been recently bored out. I replaced the cam chain, and the rollers and tensioner. I have also got the wiring patched together. The starter works, and so do all the indicator lights. I have driven it to work a couple of times now. It runs nice. Just today I took it on the highway for the first time, it too small to be a good road bike but it has plenty of power. My only 4 cylinder Kaw was a beat up 454. This bike is a whole other animal in comparison. It is fun to drive, a good balance of wieght and power. The Kerker exhaust gives it a beautiful note when you get on it, and an angry rumble when you let off, ahh yes fun stuff.

The original engine is still in thw early stages of a rebuild. I found a head, and order springs and seals form Z1. I am going to polish the ports and have the vales geound and lapped. I am still palnning od a 700cc wiseco piston kit.

By t_f_b , shot with Canon PowerShot SD400 at 2008-06-01


By T_F_B at 2008-06-01


By t_f_b , shot with Canon PowerShot SD400 at 2008-06-01

Hi all, it has been a long cold winter and I think the Sun is starting to to win the battle, spring is comming and that means i need to get going on my project bike again.

I have done quite a bit of reading and research this winter, trying to get my game plan figured out for this bike. I am looking for some feedback on the mods and repairs I am planning.

1. Engine - I had planned originally to put a 700cc Wiesco kit in the motor. Not cheap by any means, the other option is to put a 750 cylinder bank on the engine. Seems like the second choice would be cheaper and make more power. Anyone care to weigh in on this?

2. I am going with a Dayna ignition pickup and new coils. There is no rev limiter in a set-up like that. Any other option I can consider here? I am not going to be racing this bike, but I do want it to M-O-V-E when I get on the throttle.

3. Carbs - need lots of input here guys. I understand the stock 650 Mikuni's don't offer the best performance. I went through them last year to get the bike running, but they need a thourogh overhaul. Is it worth it to have them gone through (WG carbs for example) or should I look for something else.? My stock air box setup is complete, and works fine, is there a real benefit to running pod filters?

Hey man! Your doing an EXCELLENT job on that bike!!! Im really glad to see the fender,bars and headlight on it! The KZs have a very unique beauty that should be preserved if at all possible!And hey, I love those cafe set ups too!rstnick,has my favorite "rickman" set up!!! Good job man!!!

You have done well so far Tyler.

Engine - Cost wise finding a decent 750 motor may be cheaper and give you more power, as long as the motor is in good shape to begin with. 750's are only 738 cc, so really not much of a gain.
A rebuilt 700 motor will have plenty of power, and you'll know the condition of the motor having done it yourself.

Ignition - A 750 motor will have a factory electronic ignition, so if you go with an engine swap, you'll be set once you covert your electrical over.
The electronic ignition will also swap onto a 650 motor, that's what I've done (after going form points to Dyna S, frying that, back to points and now to a Kawi elec. Ign.), finding parts through ebay.
A rev limitter is not needed.

Carbs - depends on you engine choice. Some have switched to 26mm or 28mm Mikunis from the 900/1000s. If you go with a 750 engine, you may just go with the carbs that were meant for them (CV or BS?).

Check out the 650 forum link in my signature. Lots of 650 specific info there as well as other members who have done similar set ups as to what your attempting.

Thanks Zoro for the compiment.

I took apart my orginal head and bagged up the parts. I have a replacement head I bought on e-bay that is in really nice shape. The seller claimed it only had a few thousand miles on it, and it looks like he told the truth. I am going to grind the valves and port and polish the new head. I made a few tools to aid in dissasembly. The first is an extension for my valve spring compressor and the second is a wrench to remove the exhaust studs without mnaring them up. It is so nice to own a lathe...


By t_f_b , shot with Canon PowerShot SD400 at 2009-03-21



By t_f_b , shot with Canon PowerShot SD400 at 2009-03-21



By t_f_b , shot with Canon PowerShot SD400 at 2009-03-21


Since I have a junk head I decided to practice porting on it. I have never done a motorcycle head before. Its not much different than automotive work, things are just a lot closer togther. I also played around with different bits to see what worked the best. I got some cheap diamond burs that work well in the small spaces around the guides. You can see in the pictures that the factory chamfered the ends of the runners where the carburator boots are to eliminate a sharp edge. But the casting is pretty roungh, there is a parting line the runs down both sides of the runner from the mold plug. Thats all gone in my test port.

Unported intake runner


By t_f_b , shot with Canon PowerShot SD400 at 2009-03-21

Ported intake runner


By t_f_b , shot with Canon PowerShot SD400 at 2009-03-21

Unpolished intake chamber


By t_f_b , shot with Canon PowerShot SD400 at 2009-03-21

Polished intake chamber


By t_f_b , shot with Canon PowerShot SD400 at 2009-03-21

Not really much of a port job, I only opened the runner up about 1/16" but the the casting cleaned up nicely. I also opend up the carburator holder and chamfered the back side to remove a sharp edge. Probably not needed but it can't hurt, and I was just palying around with it. Next I try the real thing...

My cylinder came back form the machine shop in Fargo. I checked the ring gaps and piston fit.



By t_f_b , shot with Canon PowerShot SD400 at 2009-04-10

Nothing quite as pretty and a high performance piston in a overbore cylinder.


By t_f_b , shot with Canon PowerShot SD400 at 2009-04-10

Cylinder Head is DONE! Turned out nice, and it better becasue I had to do the valve job twice. :blush:

This was a later model head. It had the air ports for emmissions and the valve cover had reed valves in it. I pluged the air ports with a 3/8" UNF setcrews. The holes in the casting were just about the correct size, I didn't have to drill I just used a bottoming tap. I have an older valve cover to put on it, so the exhause air injectection stuff will be completely removed.


By t_f_b , shot with Canon PowerShot SD400 at 2009-04-10


By t_f_b , shot with Canon PowerShot SD400 at 2009-04-10

Now on to the lower end and transmission. Time to split some cases...:woohoo:

Splittin Cases...


By t_f_b , shot with Canon PowerShot SD400 at 2009-05-03


By t_f_b , shot with Canon PowerShot SD400 at 2009-05-03


By t_f_b , shot with Canon PowerShot SD400 at 2009-05-03

The lower end wasn't in too bad of shape. Mains and rod bearings had some pitting. The crank journals are fine, but the bearings will be replaced. I also ordered every seal and O-ring, a bit spendy when you add them all up. I think I will also replace the rollers and springs in the starter clutch. Soliting the case when very smoothly, only took about 2-1/2 hours start to finish. This is the first Kaw i have done this on, the factory manual is a big help. I used the same "bag and tag" method I did as a mechanic.

I also discovered the PO made some modifications for an oil cooler.


By t_f_b , shot with Canon PowerShot SD400 at 2009-05-03


By t_f_b , shot with Canon PowerShot SD400 at 2009-05-03

Can I find a cooler from a GPZ or are thier aftermarket products I should look for? What about a check valve? I will need to track down a cooler when I get the engine back together.

While I am waiting for parts for the lower end, I sand blasted all the tins, found a paint code and sent them to the local body shop. WG has my carbs, and I have all the chassis parts I need. I need to get my ignition work going as well. I think I will go with the Dyna S pic-up and coils. I also have to clean up the frame, and figure out my head light and turn signals.