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Author Topic: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)  (Read 55727 times)

Offline hallin222

  • Posts: 163
  • aka: HonkyKong
    • HonkyKong Customs moto-art
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #80 on: Oct 07, 2012, 23:47:07 »
Interesting to use copper pipes.  Have you heard of any problems with it?  Are the inner & outer diameters the same?  I haven't taken my carbs off yet to see. 
I haven't been made aware of anything to be concerned about due to the use of copper.  This is pretty heavy guage stuff, and I plan to support the weight of the carb somehow also.  The intake ports measure just about exaclty 1-1/2" in diameter, so the standard size pipe should work well.  I could just stuff these into the stock rubber boots, but I'm going to try to make some flanges to replace them.

Offline blipside

  • Posts: 12
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #81 on: Oct 08, 2012, 13:59:18 »
Cool.  I'm interested to see how things turn out.  I want to move to a single carb also.

Offline sinbad85

  • Posts: 330
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #82 on: Oct 09, 2012, 06:17:01 »
nice progress man!

Offline Bobbed_out

  • Posts: 396
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #83 on: Oct 12, 2012, 23:21:26 »
Looking good...
76 kz400- bobber project
75 cb360-cafe project
90 vfr750-???

Offline hallin222

  • Posts: 163
  • aka: HonkyKong
    • HonkyKong Customs moto-art
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #84 on: Oct 21, 2012, 12:52:00 »
Minor updates.  I installed some 11" shocks (aftermarket Harley Sportster, Dyna, FXR, type).  These things are crazy stiff, so I'll need to back off on the preload.  I like the stance, and that the swignarm and lower frame rails both sita bout parallel with the earth, but don't like what the lower rear has done to the look of the muffler angle, which used to be closer to parallel with the ground.  I don't have a ton of room to angle them back up, as the fit near the frame and oil pan is very tight.

The pipe 'sag' doesn't actually look this bad in person, but I was trying to get the viewing angle that would make it as obvious as possible.

To get these to fit, I swapped the rubber and steel bushings from the stock shock over to these.  Also, the lower eyelet cylinder needed to be ground down to fit the female swingarm mount.  No big deal, but it took a few minutes to get it all to fit right.



Comparative photo with stock shock length:







Very short travel shocks.  Probably only about 1.5" of functional travel, but who cares.  I'm not building a touring bike here.




All of the tight sports should still clear, even if these things bottom out.



NEXT UP:  I plan to 'properly' lower these forks via internal spacers, and increase the spring preload while I'm at it, because the front end is WAY too soft.  I was going to use this method: 

http://www.xs650chopper.com/2009/06/mulligan-machine-lower-your-xs650-forks-low-buck-garage-tech/

Any concerns with this?  I'll cut maybe 1/2 less from the springs than the amount of spacer added to help stiffen it up.  Has anyone out there done this to a KZ750 twin?  They look to have all the same guts as the XS650 model shown in that link.

Offline JordanCFH

  • Posts: 49
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #85 on: Oct 21, 2012, 18:13:51 »
Loving the stance bro! I barely noticed the problem you mentioned with the exhaust, you can probably get away with it....but like you mentioned you were gonna lower the front forks? that may help correct it visually?

Offline Pablo83

  • Posts: 123
  • Sleep, wrench, ride.
    • Catamount Motorcycles
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #86 on: Oct 22, 2012, 02:25:20 »
I think the horizontal pipes looks better.  Why are you swapping the shocks if the new ones are too short and too stiff?
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Offline hallin222

  • Posts: 163
  • aka: HonkyKong
    • HonkyKong Customs moto-art
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #87 on: Oct 22, 2012, 10:47:17 »
I think the horizontal pipes looks better.  Why are you swapping the shocks if the new ones are too short and too stiff?
As stated, the exhaust angle in that photo is exaggerated.  I can probably raise them back up a few degrees by adjusting my rear hanger under the frame and get them back to near-horizontal again.  Why do the shock swap?  I wanted a low, fat-ish bike and that's not likely to happen with the stock length shocks.  I'm also a heavier rider rider, so stiff springs are ok, and I'll be attempting a near equal increase in fork stiffness soon.

Here is the exact same image, rotated 1.5 degrees, to place the bottoms of the tires in the same plane.  This is a better representation of what it actually looks like.


Offline tobiism

  • Posts: 328
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #88 on: Oct 22, 2012, 10:59:51 »
Bikes looking great!  I do however recommend a mod to your taillight/license plate bracket.  I give it about 20 minutes of normal road use before it snaps off at the bolts under the tail.  I would add another plate below that connects all 4 bolts together.  This will strengthen it quite a bit more than it already is.  Now its just a diving board.

Offline hallin222

  • Posts: 163
  • aka: HonkyKong
    • HonkyKong Customs moto-art
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #89 on: Oct 22, 2012, 13:00:10 »
Bikes looking great!  I do however recommend a mod to your taillight/license plate bracket.  I give it about 20 minutes of normal road use before it snaps off at the bolts under the tail.  I would add another plate below that connects all 4 bolts together.  This will strengthen it quite a bit more than it already is.  Now its just a diving board.
I was considering doing something similar to 'box' that section, both for rigidity and also to help hide the rear of the tail lamp's socket. These parts weigh almost nothing.  That tail light is tiny.  Rebuilding this assembly out of steel rather than aluminum may be a good idea too.