Author Topic: Long Lost 1978 750K  (Read 6288 times)

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Offline moham

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Long Lost 1978 750K
« on: March 31, 2008, 03:18:28 PM »
I came to this bike not knowing anything about motorcycles, Hondas, SOHCs or otherwise. All I knew is that every time I was in my father-in-law's shop, I would see this bike stuck in a corner collecting dust (and more). It took me a year of dropping subtle (at first) and then not-so-subtle hints (e.g. moving all the crap out of the way and pulling the bike out myself, then asking for a key) and he finally relented and let me at it. A little work trying to get the thing to fire up (testing ignition, etc) was instructive and it wasn't too long before I found this forum.

Needless to say, I quickly filled in the gaps (actually one large gap) in my mechanical background and I got into the carburetors (took the longest of all), points assembly, plug wires, plugs and air cleaner. Thus begins the first set of photos...
78 750K-The Ocho
74 550-The Cherry Picker
70 750K0 motor-Dick in a Box

Offline moham

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Re: Long Lost 1978 750K
« Reply #1 on: March 31, 2008, 03:21:21 PM »
Then came the master cylinder, tires, chain, (530), sprockets and pipes...
78 750K-The Ocho
74 550-The Cherry Picker
70 750K0 motor-Dick in a Box

Offline moham

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Re: Long Lost 1978 750K
« Reply #2 on: March 31, 2008, 03:22:41 PM »
headlight and more...
78 750K-The Ocho
74 550-The Cherry Picker
70 750K0 motor-Dick in a Box

Offline moham

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Re: Long Lost 1978 750K
« Reply #3 on: March 31, 2008, 03:24:34 PM »
some attempts at chrome polishing and general cleaning (not much)...plus the old pipes (sad, I know...)
78 750K-The Ocho
74 550-The Cherry Picker
70 750K0 motor-Dick in a Box

Offline moham

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Re: Long Lost 1978 750K
« Reply #4 on: March 31, 2008, 03:27:00 PM »
getting closer...(note the mileage and the plates...funny thing is, my father-in-law has kept the registration up for the last thirty years even though he has ridden it since '83)
78 750K-The Ocho
74 550-The Cherry Picker
70 750K0 motor-Dick in a Box

Offline andy750

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Re: Long Lost 1978 750K
« Reply #5 on: March 31, 2008, 03:31:43 PM »
Wow you have been busy!!! Keep going! Almost done!

Nice pic previews!

cheers
Andy

Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico, 2003 - European Tour, 2004 - SOHC Easy Rider Trip , 2008 - Adirondack Tour 2-up , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. Yamaha Tenere T700 2022

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline moham

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Re: Long Lost 1978 750K
« Reply #6 on: March 31, 2008, 03:37:15 PM »
and now, ready to ride, but the sleet, snow and rain have intervened again...Did I mention I've only been on a bike twice in my life? Well, much fun to be had soon...
78 750K-The Ocho
74 550-The Cherry Picker
70 750K0 motor-Dick in a Box

Offline Spikeybike

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Re: Long Lost 1978 750K
« Reply #7 on: March 31, 2008, 04:35:17 PM »
damn i thoght i was fast  ;D. looking good

Offline 78CB750CAFE

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Re: Long Lost 1978 750K
« Reply #8 on: March 31, 2008, 06:07:06 PM »
NICE  ::)
"I believe in the bodies, I believe in the blood, I believe in salt around the rim of the glass because it makes us thirsty, and when we drink, then we all fall in love"
-212 Margarita by The Hold Steady
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Offline greenjeans

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Re: Long Lost 1978 750K
« Reply #9 on: March 31, 2008, 06:42:37 PM »
Great find...progress looks so fast compared to mine.  Hopefully the sun will shine and dry things up for your maiden voyage.     Just one thing jumped out at me:



Guys correct me if I'm wrong, but isn't there supposed to be a locking plate that goes over the drive shaft and
rotates slightly to lock into a groove... there are 2 bolts that then go into the sprocket where the red arrows are.

Might look a bit like this:


« Last Edit: March 31, 2008, 06:49:58 PM by greenjeans »
Yep, I'm the kid that figured out how to put things back together...eventually.

fixahonda

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Re: Long Lost 1978 750K
« Reply #10 on: March 31, 2008, 08:03:43 PM »
Wow, that looks beautiful! Great work.
Be careful on that first ride and good luck.

Offline mcpuffett

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Re: Long Lost 1978 750K
« Reply #11 on: April 01, 2008, 01:27:26 AM »
I noticed that to Greenjeans, but i recently took a f2 engine out and that had the same set up just the single bolt to hold the sprocket on  :-\, my f1 has the same set up as yours with 2 bolts to hold it all in place, nice resto all the same  8), cheers Mick.
Honda CB750 KO 1970,   Honda VTX 1300 2006, Lancaster England.

Offline eurban

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Re: Long Lost 1978 750K
« Reply #12 on: April 01, 2008, 05:44:10 AM »
some attempts at chrome polishing and general cleaning (not much)...plus the old pipes (sad, I know...)

Whats wrong with the old pipes? 

Offline mystic_1

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Re: Long Lost 1978 750K
« Reply #13 on: April 01, 2008, 05:50:05 AM »
Whats wrong with the old pipes? 

Based on the pic posted above, looks to me like they've rusted from the insides.

mystic_1
"A ship in harbor is safe, but that is not what ships are built for."
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My build thread:  http://forums.sohc4.net/index.php?topic=68952.0

Offline Roach Carver

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Re: Long Lost 1978 750K
« Reply #14 on: April 01, 2008, 06:49:36 AM »
Great find...progress looks so fast compared to mine.  Hopefully the sun will shine and dry things up for your maiden voyage.     Just one thing jumped out at me:



Guys correct me if I'm wrong, but isn't there supposed to be a locking plate that goes over the drive shaft and
rotates slightly to lock into a groove... there are 2 bolts that then go into the sprocket where the red arrows are.

Might look a bit like this:



my 78 k is the same way. The later sprockets are only held on by the bolt and washer apparently.

Offline moham

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Re: Long Lost 1978 750K
« Reply #15 on: April 01, 2008, 06:59:26 AM »

Based on the pic posted above, looks to me like they've rusted from the insides.

mystic_1

correct. that and the fact that one of them was home to what is now a crusty mouse, with a stash full of corn, to boot. I would have saved them if I could, but the damage was too severe, quarter size holes in all but one and the baffles disintegrated....
78 750K-The Ocho
74 550-The Cherry Picker
70 750K0 motor-Dick in a Box

Offline moham

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Re: Long Lost 1978 750K
« Reply #16 on: April 01, 2008, 07:13:52 AM »


Guys correct me if I'm wrong, but isn't there supposed to be a locking plate that goes over the drive shaft and
rotates slightly to lock into a groove... there are 2 bolts that then go into the sprocket where the red arrows are.


yeah, I was thrown by the extra holes in the sprocket when I got it all opened up...thought for sure I had the wrong part. But it slid right on with the tapered teeth of the opening fitting the shaft snugly :).
78 750K-The Ocho
74 550-The Cherry Picker
70 750K0 motor-Dick in a Box

Offline Mossy21

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Re: Long Lost 1978 750K
« Reply #17 on: April 01, 2008, 02:22:58 PM »
Are the header pipes OK ?
If I can't see the Engine I can't see the point.......

Offline mystic_1

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Re: Long Lost 1978 750K
« Reply #18 on: April 01, 2008, 02:58:35 PM »
Are the header pipes OK ?

Just what I was thinking.  Cut off the silencers and replace them, the downtubes look OK to me.

mystic_1
"A ship in harbor is safe, but that is not what ships are built for."
- John Augustus Shedd

My build thread:  http://forums.sohc4.net/index.php?topic=68952.0

Offline moham

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Re: Long Lost 1978 750K
« Reply #19 on: April 01, 2008, 04:50:51 PM »
Are the header pipes OK ?

Just what I was thinking.  Cut off the silencers and replace them, the downtubes look OK to me.

mystic_1

Thanks for the input. I was certainly planning on keeping the headers, but wasn't sure what the options were, since the pipes were all one piece. What are the options for replacement mufflers? Wouldn't they need to be welded? Are there slip-ons that are worthwhile? I had entertained the thought of trying to weld with the headers at some point, but that currently is above my pay-grade, so to speak. I love the look of the old pipes but don't really have the dough to do the oem thing. I haven't, as of yet, ruled anything out, and as the MAC was an affordable option, I am pleased so far with how they've fit, look etc...happy to know your thoughts on this...
78 750K-The Ocho
74 550-The Cherry Picker
70 750K0 motor-Dick in a Box

Offline eurban

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Re: Long Lost 1978 750K
« Reply #20 on: April 03, 2008, 04:18:49 PM »
There are probably some aftermarket 4-2 exhausts that would use your stock header pipes.  You would cut off the header at a certain length and it would slide into the 4-2 collector / muffler.  Thats about as close to "slip on" as you will find.  If you look closely at the muffler portion of your pipes,  you will notice they are "custom" shaped with bends and contours, and mounting studs built in.  You will not find a set of 4 slip on mufflers that will properly fit without a good deal of work.  . . .   My 78K has a NOS set of the stock 4-4 pipes currently on it but I have always thought about making a cool custom exhaust out of my old set.  They are all  structurally sound but have a hole or two and have their heavy internal baffling loose and rattling around inside. Here's one idea I had:  Cut the end caps off of each pipe and gut the muffler.  Perhaps cut them a bit shorter than stock.  Weld up any holes and weld in some appropriate internal mounts to allow you to mount a set of Supertrapp diffuser discs and end cap on the end of each pipe.  Have the pipes ceramic coated.  End result would not be much lighter than the 40lbs of stock pipes but would look cool and would be easily tuneable for flow vs noise.  I have always liked the way Supertrapp mufflers looked . . .

Offline moham

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Re: Long Lost 1978 750K
« Reply #21 on: April 03, 2008, 06:58:51 PM »
but I have always thought about making a cool custom exhaust out of my old set.  They are all  structurally sound but have a hole or two and have their heavy internal baffling loose and rattling around inside. Here's one idea I had:  Cut the end caps off of each pipe and gut the muffler.  Perhaps cut them a bit shorter than stock.  Weld up any holes and weld in some appropriate internal mounts to allow you to mount a set of Supertrapp diffuser discs and end cap on the end of each pipe.  Have the pipes ceramic coated.  End result would not be much lighter than the 40lbs of stock pipes but would look cool and would be easily tuneable for flow vs noise.  I have always liked the way Supertrapp mufflers looked . . .

I like that idea and it certainly opens up other ideas as well. This just reaffirms my thought to hang on to the pipes until I figure something out (as opposed to trying to unload them...) Thanks for the response.
78 750K-The Ocho
74 550-The Cherry Picker
70 750K0 motor-Dick in a Box