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Author Topic: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)  (Read 51567 times)

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #20 on: Oct 19, 2012, 23:23:13 »
z  just the balance 'factor' is changed.
     The weight I removed was on the throw side,not the counterwieght side.

2) 400 = 64* 62 ,use a KZ650 Wiseco piston @ 65mm,3 over stock 62mm
     440 = 67.5 * 62,use the KZ750 Wiseco piston @ 69mm,3 over stock 66mm

 ((Edit/When using either Wiseco pistons you can milled the head other .035 in.
            because those pistons have a shorter dome
            This will be a total of .070 in. off the head.
             Bringing the compression ratio up to roughly 10.3 with each combination.
             Milling just the original .035 will result in a 9.3 ratio.
             The valve pockets are 5 degrees off which might cause a problem with a milled
              head and high lift cam.))

The drop in pistons I have are from a discontinued Wiseco kit from eBay.
It is a drop in for the 440.

If I were you I'd do a compression check etc. first, to see what condition the engine is in.
Then if it's good leave it alone and  find another to hop up.
Because there is nothing worse than walking by a motorcycle you could be riding. 8)
« Last Edit: Oct 21, 2012, 16:19:58 by Nebr_Rex »

Offline BLSully

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #21 on: Oct 19, 2012, 23:41:34 »
Because there is nothing worse than walking by a motorcycle you could be riding. 8)

Too true. Walk by it every morning out to the truck  :-\ I just keep telling myself it'll be ready for next riding season :)
'05 Vulcan 1500 Classic - Daily rider.
'79 KZ400 B2 - http://www.dotheton.com/forum/index.php?topic=42063.0
'80 KZ440 - Actually runs.

Support these guys: www.power-barn.com www.dimecitycycles.com

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #22 on: Nov 12, 2012, 18:16:16 »
Not much to report here lately.
Been to busy trucking and bought another old pickup ('78 F250 w/460).
I'm taking vacation starting the 23 for about 10 days before I lose them.
During that time I'm planing on getting the fuel injection sorted out.
Last winter when it I had it running the injector pulse was all messed up.
This lead to fouling the plugs and switching back to carbs.
I think I have it figured out, just need to compute the values of the resistors,transistors,etc....
Oh,by the way did I mention that it is transistorised electro/mechanical fuel injection, NO COMPUTER.
That means electrical switches controlling others,along with mechanical means.
No computer chips anywhere,that's the plan anyway.
I had a leaking clutch cover gasket, so I decided to do a little painting.
Here are some pics.

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #23 on: Nov 19, 2012, 11:26:10 »
Well I forgot my vacation started on the 17th.
Planning on boring a couple of blocks sometime over the holiday.
All depends on when the owner/lead mechanic will be there after hours.
During that time I have access to their boring bar.
Will post about that later.
Today's post is about using 2 stroke carbs on a 4 stroke engine.
On Dr. Jekyll I'm temporarily running a pair of vm28s from a Yamaha.
The air bleed going to the needle jet is to large.
If you look at a 4 stroke carb there is a brass insert with a small hole like this one.



Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #24 on: Nov 19, 2012, 11:33:34 »
I used a pilot jet from a bs34 Mikuni for a restrictor.
Drilling a .8 mm or .032/32nd in. hole to start with.

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #25 on: Nov 19, 2012, 11:38:04 »
Next I tapped the air bleed with a no. 12nc (24 threads/in.) machine screw tap.
Threads are not a prefect match but real close.

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #26 on: Nov 19, 2012, 11:45:07 »
For now jetting is 15 pilot and 100 mains.
So if you are fowling plugs,maybe to much air is getting thru that little hole and forcing extra fuel out.

 

Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #27 on: Nov 28, 2012, 19:12:41 »
These were my piston options.

Offline teazer

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #28 on: Nov 28, 2012, 19:44:40 »
Next time just tap the mouth for standard Mikuni air jets which come in different sizes :-)



Offline Nebr_Rex

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Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #29 on: Nov 28, 2012, 21:00:20 »
Next time just tap the mouth for standard Mikuni air jets which come in different sizes :-)




Just using what I have on hand.
Maybe you could post your own thread on the subject.