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Author Topic: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)  (Read 47329 times)

Offline Nebr_Rex

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Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« on: Jul 09, 2012, 11:35:06 »
Thought I'd post up my latest project(s).
My pair of KZ400's.

First pic is of the Dr. Jekyll bike. Plans are to keep this one basically stock
except for the 440 with a milled head, round slide carbs,440 forks (flipped caliper).

Second pic is of the second go around for this bike.
It was first built a couple of years ago with the engine that's now in the other bike.
It was has 36mm forks, KZ550 swing arm, dual disk brakes and 2.15(wm3?) rear rim.
(120 rear/100 front)
Still have to reinstall the quarter fairing,seat, rear sets, aluminum
fenders and non stock gauges.
Need to modify the upper shock mounts and redo the tail.

Over on the KZ400 site someone claimed to make 55 h.p. with a bored out 440.
I think I can do better then that, stock being 40h.p. at the crank.
I've already acquired some n.o.s. Wiseco pistons to use.
Going to back cut the transmission also.


« Last Edit: Jul 24, 2012, 23:06:27 by Nebr_Rex »

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #1 on: Jul 24, 2012, 23:31:04 »
Got a few things done to Mr. Hyde this weekend.

First removed the tail and old battery box,will be using a ballistic battery mounted in the tail.

Second, moved the upper shock mounts for two reasons,
    1, shocks to be used are longer
    2, KZ550 swing arm is wider than the original
But.....the down tubes are to wide so I'll have to put them back behind and up against the frame.
Will be only be gaining an inch or so in distance between mounts, but should work out better for ride height and clearence.

And 3, fired up the lathe made a rear axle spacer.


.

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #2 on: Jul 28, 2012, 18:18:03 »
Started tearing down the engine for Mr. Hyde today.
Everything looks good, now to see about taking some weight off the rotating assembly.
And bore the block,back cut the trans....


        ...but first the head needs some attention.....

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #3 on: Jul 28, 2012, 18:21:44 »
I have some new carb boots for the vm34s,look a little bigger then the original.

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #4 on: Jul 28, 2012, 18:26:07 »
Found something out about the rods also.
I knew the bearings and pins were the same,excluding the turbo pin at 16mm.
The 440 rod is about 1/4 in. longer.

(Correction...bearings and pins are the same as the KZ650/750 4s.)


« Last Edit: Jul 30, 2012, 18:17:38 by Nebr_Rex »

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #5 on: Aug 06, 2012, 13:25:20 »
Not much to report.
Finished tearing down the engine and sent the head the machine shop to be milled.
Soaked the head and cases in Pine Sol over night.
They needed a little scrubbing , but  all deposits were softened up for easy removal.
I think with a little agetation or movement of fluid such as a pump it will work better.
Might have to replace the solvent in the parts washers with Pine Sol. 8)


Offline Shermanator86

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #6 on: Aug 20, 2012, 16:00:14 »
I have some new carb boots for the vm34s,look a little bigger then the original.

Looks like you got a nice start man.

Just something for thought, on the original head on my bike the previous owner had over tightened the screws on the carb boots and actually busted up the threading and surrounding boss. Don't know how easy that is to do but to prevent it from happening with my new one I just made some studs out of some bolts I just cut the heads off.


I'll be watching this thread for sure though, I know ever since I read the thread on that guys race bike over on the twin owners forum I've wanted to throw some money at my motor like that to.
1978 kz 400 single carb, now 440 top end hybrid
http://www.dotheton.com/forum/index.php?topic=28708.0

2008 Suzuki SV650

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #7 on: Aug 21, 2012, 00:09:57 »
What gave you the idea I have trouble with intake bolts?
The big carb boots are on purpose.
They are for vm34s Mikunis which are a round slide carb not the stock bs36 Mikunis.
Along with the port that is going to be bigger,but relocated 3/16 in. horizontally and 3/16 in. vertical.

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #8 on: Aug 21, 2012, 00:57:56 »
Also while I was home this weekend I picked up my head
Had it milled just enough to remove the lip the factory leaves.
This takes off 3 cc from the chamber.
I measured the head on the other bike that I had already had milled before(33 cc) vs. a stock(36 cc) vs. a early 400 head (34 cc).
Along with 1 cc for removal of the base gasket and using 1194.
Will bring the piston to zero deck height.
And a static compression ratio of about 10.6/1 from the factory 9.2/1.
If the factory rating is correct then my math should be close.

   221.5+27/27=9.2.    27-4=23.   221.5+23/23=10.63

You can see the line I scribed on another heads combustion chamber for reference.

But,I am not using stock pistons.
The pistons are from an old Wiseco big bore kit for the 400.
Same bore as the 440 with a dome like the early 400s.
Listed at 10/1 on the paperwork, on my application it'll be 11.8/1. ;D
And if that's not enough I have other option yet.

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #9 on: Aug 21, 2012, 01:06:08 »
And one last thing, stock crank weighs 15 lbs. 5.2 oz..
Mine weighs 12 lbs. 4.0 oz. so far with a couple more or so to come off.
Here is a pic of the crank as pulled from stock  engine.