79 Kawasaki KZ650 - 8 minute video, 282 West, Pennsylvania

[xb33bsa]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

that looks bitchen man nice work 8)
seeing is how you have it up the bench why not learn some more valuable fun shit and see how close to optimal the cam timing is
you dont HAVE to change it but you may find you want to
its really critical stuff and a few degrees off is a noticable power thingy
there is lots of information on the 650 somebody has got to have a verified sweet running lobe centers spec
it just a matter of slotting the sprocket holes with a chainsaw round file if you decide to degree it in to stock or a known tuner spec
see even making sure it is exactly stock like the engineers meant it to be can make a great difference if they are off, this is part of what is called blueprinting,see,learn shit impress the crowd with an expanded jargonish

 

[crazypj]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

I hope you put the circlips in properly?
The video guy says open at top OR bottom?
In a high rpm engine, never ever have open end at top as there is more chance of the inertia at TDC (when piston is moving fastest) causing the extra mass at bottom to make clips close up and pop out. For a professional mechanic, he doesn't know much but at least he didn't tell you to put gap in the middle (where even the Z would rev high enough for them to fall out).
On '650' it's retty doubtful you will be revving it high enough to matter but on latest 4 stroke MX singles it's a good possibility

 

[AlphaDogChoppers]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

How is the inertia at TDC different from the inertia at BDC?

 

[SrgtBear]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

I really doubt those piston circlips are going anywhere. I mean, yes, anything is possible, but seeing how hard they were to get in they seem strong enough to do their job. Secondly at this point I would refrain from messing with them seeing how easy it is to accident bugger something up.

I'm at the point of no return now. Fingers crossed!


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[crazypj]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

How is the inertia at TDC different from the inertia at BDC?

because of connecting rod angle, piston slows down 'slower' at BDC compared to TDC
I thought you of all people would already know this?

 

[AlphaDogChoppers]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

I wouldn't think it would make enough of a difference to make a difference.

 

[crazypj]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

I don't remember exact numbers but HD XR750 rod end goes from zero to 80mph in about half inch from TDC.
At BDC it takes 2 to three times further to reach same speed.
I have a chart somewhere for XS650 piston acceleration but don't remember which hard drive it's on
Apparently, the mayth is 'fairly simple' but I can't do it

 

[AlphaDogChoppers]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

The bike here is an in-line 4. I don't think they have much crank offset.

 

[crazypj]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

I'm aware of that but ithas capability to rev higher than XR or sportster.
It's doubtful there is going to be a problem but the information is sound.
Pretty sure HD specifically state the correct way to insert circlips but majority of manufacturers don't give any instructions.
I have seen engines where clips have popped out, never on one I've built though.
It's just something I've done 'forever', I used to spend way too much time thinking about stuff like this when I first started messing with bikes 47 yrs ago. I didn't get verification that what I was doing was correct until I started teaching at MMI in 2000

Sorry for the 'threadjack' but I need to explain stuff :-[

 

[hillsy]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

I'm at the point of no return now. Fingers crossed!

You'll be fine. Don't worry about this sort of stuff.

 

[SrgtBear]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

You'll be fine. Don't worry about this sort of stuff.

WebMD of motorcycles. Worry about shit before you even have a problem. Lol.


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[CarbsAndCylinders]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

http://www.epi-eng.com/piston_engine_technology/piston_motion_basics.htm

Interesting, I didn't know this before, it seems counter-intuitive.

 

[crazypj]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

I haven't looked at graphs like that in probably 45 yrs
If I had been any good at math I would have been a mechanical engineer, calculus may as well have been Martian to me though ;D (we were still using slide rules in 1970's, handheld calculators were not available until about 1976?)

 

[SrgtBear]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

Quick update:

Getting to the home stretch with this project. This weekend I dropped off my engine brackets and chrome crash bars to get powder coated. I also rebuilt the front brake caliper...blasted and painted. Pitted bolts still need to get replaced.

After this is just dropping the engine in, working out a few odds and ends, and finish with electrical and wiring harness clean up. Paint job will probably wait till next season because I'm desperate to ride the shit out of this bike.

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[xb33bsa]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

http://www.epi-eng.com/piston_engine_technology/piston_motion_basics.htm

Interesting, I didn't know this before, it seems counter-intuitive.

that is a grate reed i like how they use different color powerbands on the chartmaps ,green ,yeah,i like the green powerbands,yeah green

 

[SrgtBear]

Re: 79 Kawasaki KZ650 - I goofed, wrong head gasket

Got the engine in the frame. Powdercoated crash bars. Making progress.

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[SrgtBear]

Re: 79 Kawasaki KZ650 - Engine made it into the frame

Here's the paint I was thinking about for her tins. Wanted to document on the forum so I didn't forget.

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[SrgtBear]

Re: 79 Kawasaki KZ650 - Engine made it into the frame

I assure you that I am still working on this bike.

So there is always something that needs extra attention with these old bikes. During disassembly I had to cut a long engine bolt because it was frozen. When installing I didn't have that bolt so I tried to make one at first but I needed a hex bolt end and couldn't get the job done with two threaded ends. Luckily a 10m bolt from a KZ1300 that fit just fine. Also I had some camshaft cap threads strip during assembly. So I went back and fixed them with Helicoils. All my buddies said 8ft-lbs of torque on those is wrong. Do 6-7 or hand tighten. Apparently it's a reoccurring problem with these KZs.

So in addition to that I put a chain on it. First time for me so it took me awhile to press and link and rivet the ends. I think I did it right. You can see a small crack on one of the rivets but that's nothing worry about. Most people end up splitting both ends.

Finally I was cleaning up the electrical connectors and noticed some fried terminals. I re did them and shrink wrapped it for protection.

Here are some pics.

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[xb33bsa]

Re: 79 Kawasaki KZ650 - Helicoils, Chain Rivets, Electrical

the bike looks great,people tend to get overworried babout riveting the pins the crack woont keep going or do any harm
future reference it only takes a little bit of upsetting the head to make it absolutely secure,5-10 thousanths over pin size is sufficiernt,calipers to verify this, there are not any significant forces attempting to remove the link plate during use
i prefer to used a tight fitting more handilly removable master with clip ,they are perfectly safe
its also a good idea to verrify the link is fully put together and not to far together by comparing width with calipers to a std link in the same chain

 

[SrgtBear]

Re: 79 Kawasaki KZ650 - Helicoils, Chain Rivets, Electrical

the bike looks great,people tend to get overworried babout riveting the pins the crack woont keep going or do any harm
future reference it only takes a little bit of upsetting the head to make it absolutely secure,5-10 thousanths over pin size is sufficiernt,calipers to verify this, there are not any significant forces attempting to remove the link plate during use
i prefer to used a tight fitting more handilly removable master with clip ,they are perfectly safe
its also a good idea to verrify the link is fully put together and not to far together by comparing width with calipers to a std link in the same chain

Thanks. I'm in the electrical phase. It's getting real close to being started up. Still got to do carbs, throttle cables, clutch cables, and a few more repairs of someone else's electrical work. I think I might wait till next season to get her painted. I'm really hoping I get to ride her this fall before it's too late.