1972 Honda CB 750 K2

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HIKO

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Nov 7, 2005
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Eddie,

I don't want to argue with You but the CB 750 K2 never had black colored cylinders...

MP-Terveisin Hiko
 
KZ25

KZ25

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Nov 19, 2011
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Some XS650 models had black barrels in the late seventies or early eighties. Personally I never liked the look, all aluminum looks better, but that's just me.
 
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Eddie The Eagle

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Sep 8, 2009
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HIKO;287952 wrote: Eddie,

I don't want to argue with You but the CB 750 K2 never had black colored cylinders...

MP-Terveisin Hiko
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Your absolutely right Hiko, all K series engines were alloy color, black was my personal choice ... This CB750K1 will be alloy color.

safe riding .... EB.
 
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Eddie The Eagle

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Sep 8, 2009
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KZ25;287951 wrote: The bike looks great now, all new and shiny! A real Japanese classic, not many Jap bikes deserve that title.

Is that an old California license plate in one of the photos?
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Yes KZ that license plate came with the bike, its now got a Thai plate (750) ... The pics your looking at was the one I restored last year,im now restoring a K1 (1971)....
I like to get my hands on a XS650, original one's getting hard to find now .... Ride Safe ... EB
 
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BobSriRacha

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Feb 16, 2013
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brake034;287953 wrote: Hi Hiko,

Eddie does not state that, he refers to other bikes who had it, so it was around during the early 70's.

Actually my old Norton and Velocette had black cylinders, it just did not last that long.....
Modern aluminium coatings or surface treatments last a bike's lifetime and that was not the case in the early 70's.

I have worked with metal industrial products a long time, aluminium castings are investment casts, is is said they integrity of the investment casting is much better then sand castings.
Sand casted crank cases may be they are rare but certainly not considered to be better castings.
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Hi all, first post from a 'newbie'...

just picking up on Marcel's comments about aluminium castings and motorcycle engines -

From my experience, crankcases are usually high pressure die cast to get a good finish, precise detail thats required, good casting integrity (no porosity or shrinkage where you dont want it) and consistency of product, but it requires very costly equipment and die tooling. Barrels (if separate parts) and cylinder heads are usually low pressure or tilt-pour cast as it costs less to set up but still gives the required casting integrity and external finish.

Investment casting (developed by the Egyptians as the 'lost wax technique) is used for smaller steel or aluminium parts is a low set up cost method that gives a good finish and consistent results.

Sand casting is not the first choice of process for aluminium parts that require a good finish and consistency - sand by its very nature leaves a more rough surface and is easy to damage while the die mould is being assembled. But its relatively quick and lower cost to set up or modify. It may be used while the preferred method is being finalised. Possibly Honda had some issues with their chosen casting method and so had no choice but to use sand cast for a limited number of early bikes... Or the whole project would have been delayed...

Think I've rattled on enough... Great site!
 
KZ25

KZ25

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Nov 19, 2011
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Eddie The Eagle;287961 wrote: I like to get my hands on a XS650 ... EB
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I was extremely lucky to discover a '81 XS650 at a repair shop in the US in 1994. It had only 500 mi on the clock, the owner brought it in for an oil change and never returned.

All it needed was new rubber, a battery, clean carbs and lots of elbow grease. And legal papers.

Had it for seven years, put only 4,000 mi on it and couldn't get more than $300 for it when I left.
 
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Eddie The Eagle

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Sep 8, 2009
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Eddie The Eagle;287960 wrote: Your absolutely right Hiko, all K series engines were alloy color, black was my personal choice ... This CB750K1 will be alloy color.

safe riding .... EB.
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Regarding engine color .... Change my mind ... Decided to do the K1 engine black, A good contrast with all that chrome & polish alloy ... The paint work will be candy gold ... EB.
 
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techy5025

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Nov 10, 2008
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You did a great job on the '72. I have to especially compliment you on your polishing of the aluminum parts....alternator cover, etc. Been there..done that.....those look beautiful! The painter did a great job, too. I had mine painted by a local guy using a "paint kit" that is sold on eBay and matches the original Honda colors.

I would probably go with a bare aluminum engine as I am an "original" guy, but the black color looks good too.

The left bike.. in the pic of my bikes up thread...I've owned since '69. I think I'm on my 3rd set of mufflers. The sandcast on the right I restored off of eBay. If you keep oil in these bikes they will run forever....great bikes.

Jim
 
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