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Author Topic: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)  (Read 52845 times)

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #30 on: Nov 28, 2012, 21:32:00 »
From left to right;
 
  1)  Old Wiseco big bore KZ400 piston,listed at 10/1,12 cc dome,11.5/1 for my application, 67.5 mm (440 bore ) 223 grams

  2)  Wiseco KZ750/4,5.2 CC dome,8.3/1 with the stock 440 combustion chamber,9.3 for me,69 mm,239 grams

  3)  Old JE(?)  piston for a KZ750/4, modified/lightened skirt, 68 mm, taller dome than piston no. 1, but deeper valve reliefs, maybe 1 CC more dome volume than no. 1, my calculations come up with 11.7/1, 238 grams

  4). Unmodified version of no.3, 252 grams

I'll be using a head that is milled .035 in. and no base gasket.
« Last Edit: Nov 28, 2012, 21:35:57 by Nebr_Rex »

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #31 on: Nov 28, 2012, 21:40:51 »
I decided to go with the old high domes with the modified skirt.
Freshly bored and honed cylinders.

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #32 on: Nov 28, 2012, 21:44:00 »
A mock up of what it will look like when assembled. 8)

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #33 on: Nov 28, 2012, 21:53:06 »
Almost have the wiring done on Dr. Jekyll.
Wiring a KZ440 engine and charging system in a KZ400 frame.
Making sure everything works with extras for the future addition of fuel injection kind of sucks.

Offline teazer

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #34 on: Nov 29, 2012, 01:25:28 »
Just using what I have on hand.
Maybe you could post your own thread on the subject.

I'm not being critical.  Hope my brief response didn't come across that way. :-)

We have to do that mod on almost all GT750s with stock BS40 carbs because they surge. Suzuki used to sell special air jets which of course were available from Mikuni for a whole lot less.  I have a reference to that carb at http://pinkpossum.com/GT750/carb/BS40carbs.htm

BTW, nice collection of pistons.

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #35 on: Nov 29, 2012, 22:17:29 »
I knew the Holley tuners used removable air jets.
Didn't know about Mikuni's.
I think I need to take a harder look at the Sudco catalog.
Do you know what size thread is required?

Offline teazer

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #36 on: Nov 29, 2012, 22:55:46 »
Hmm.  I forgot to include that in the blog.  I'll go and measure one.

edit: I just checked and it's a 4mm x0.7mm tap which is available from any decent hardware store - mine was from our local ACE.  Air jets are used extensively in larger VM carbs.  Typically two strokes are 2.0mm or no jet and 4 strokes are much smaller.  On the Suzuki GT750 we add a replaceable air jet to the pilot air system to trim slow riding stumbles.
« Last Edit: Nov 29, 2012, 23:12:15 by teazer »

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #37 on: Nov 30, 2012, 21:31:35 »
Hmm.  I forgot to include that in the blog.  I'll go and measure one.

edit: I just checked and it's a 4mm x0.7mm tap which is available from any decent hardware store - mine was from our local ACE.  Air jets are used extensively in larger VM carbs.  Typically two strokes are 2.0mm or no jet and 4 strokes are much smaller.  On the Suzuki GT750 we add a replaceable air jet to the pilot air system to trim slow riding stumbles.

Thanks for the reply,the info will be put to good use.

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #38 on: Jan 01, 2013, 11:41:57 »
Finally got Dr. Jekyll rewired and all the stock circuits are working.
It will need to be 'refined' for a better fit at a later date,I might even get it color coded.
I'm have choosen to use the turn signal lights from a small Honda CB bike.
Was going to use them on Mr. Hyde, but they look better than the huge stock lights.
Probably end up just running a head and tail light on the evil one.
Also been messing around with getting my fuel injectors to fire.
I have visited the local Radio Shack more than the auto parts store lately.
Earlier I had it running off the pickup coils and two ignitor boxes.
Had the dwell/pulse width running from about 24 at idle to 41 at high rpm.
With some transistors and resistors soldered to a circuit board I'm getting .001 to .01
of pulse width according to the Chinese meter from harbor freight I'm using.
So the next time I'm home I'll be 'refining' my harness for a better fit.
Then the fuel pump,throttle bodies, etc. can be reinstalled and see how it runs as is.


Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #39 on: Jan 13, 2013, 23:40:35 »
Been doing a little experimenting with some circuits.
It's slow going since I have to self teach myself.
Seem I have forgotten everything I learned in high school electronics class.

First pic is of what hasn't worked so far.
Second pic shows a more complex circuit I just finished.
Testing will have to wait until next time I'm home.