Author Topic: 750 project  (Read 5207 times)

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Offline Bert

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750 project
« on: December 05, 2017, 01:02:02 AM »
I have been working in my fathers old bike. He bought it new in 1973. When he purchased it he also picked up a "hot cam" and a smaller front sprocket. He is pretty short so he lowered the rear and swapped out to a 16 inch rear wheel. He did the lowering project but never installed the cam.

In the early 80's a cousin (Zeek) purchased the bike from him. Zeek ditched the lowing blocks and installed the cam. Somewhere in there the sprockets both were changed as well, back to stock. Then in 1990 he parked the bike. It sat until last summer when I purchased it.

I don't know when the exhaust was changed, I'm assuming that Zeek did, but I forgot to ask him.

While the bike was parked the roof collapsed on the barn it was stored in. The roof twisted the sissy bar, the very back tail of the left side of the frame, bent the handlebars, mangled the gauges, headlight and top of the triple tree.

As luck would have it I was also able to purchase a donor parts bike this summer off craigslist. This gave me all the parts that I needed.

Sorry for the long story, but that's the history as I know it.

Now that I have the bike I'm just hoping to get it functional, not necessarily a complete resto.

Here's a picture of when I picked it up, and what it looks like now (parts bike in the background)



Offline Stev-o

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Re: 750 project
« Reply #1 on: December 05, 2017, 06:40:09 AM »
No need to apologize, that is a great story! What is next?  Suggest tapered bearings for the front end...
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline CycleRanger

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Re: 750 project
« Reply #2 on: December 05, 2017, 06:41:42 AM »
Cool story and great project! :)
Do you have a copy of the Honda Shop Manual or Parts List for your bike? Get one here:
https://www.honda4fun.com/materiale/documentazione-tecnica
CB750K5        '79 XL250s     CL350K3
CB750K3        '76 XS650      '76 CJ360T

Offline SOHC4 Cafe Racer Fan

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Re: 750 project
« Reply #3 on: December 05, 2017, 09:42:31 AM »
Great story and name (Zeek).

Is the motor freed up or seized?
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline Johnie

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Re: 750 project
« Reply #4 on: December 05, 2017, 12:03:58 PM »
For parts contact member Bill Benson he has the stash and most of the guys say he is pretty decent :)
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA

Offline Bert

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Re: 750 project
« Reply #5 on: December 05, 2017, 01:33:33 PM »
Luckily the motor is still free. The odometer reads about 20k, but I don't think it's the correct gauge. I don't think it's supposed to have the high beam and signal light in it. The parts bike instruments aren't pristine, but I hope they work.

I guess my next step is to piece the bike back together with the best parts between the two. Along with some new items, such as cables, tires and carb parts.

I am apprehensive about the carbs, they don't move and I popped one bowl and it's a bit cruddy. I believe they can be saved tho!

The last photo is an up to date where it sits.... please excuse the mess!

(Edit: photos seem to mess up my posts. To large of files maybe?)

Offline Bert

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Re: 750 project
« Reply #6 on: December 05, 2017, 02:10:58 PM »
Parts bike instruments

Offline lash

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Re: 750 project
« Reply #7 on: December 05, 2017, 02:30:34 PM »
Gauges are 1971. Good project , keep us updated
Analog mind in a digital world..

Offline seanbarney41

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Re: 750 project
« Reply #8 on: December 05, 2017, 02:39:58 PM »
Some very early K2 models came with the K1 gauges.  Bert, although you have been calling your bike a '73, and it probably says 1973 on the title, I bet if you check the vin and the build date on the frame tag, you will find that your bike was built in late 1971 and is a K2.  Honda did not follow the western model/year designations we are familiar with at this time.
If it works good, it looks good...

Offline Bert

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Re: 750 project
« Reply #9 on: December 05, 2017, 03:03:46 PM »
The date on the tag is 5/72, no 2040907. The parts bike is 11/71.

Offline Bert

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Re: 750 project
« Reply #10 on: December 05, 2017, 03:21:43 PM »
Here's a peek at a carb.... ick

Offline 754

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Re: 750 project
« Reply #11 on: December 05, 2017, 03:24:41 PM »
That looks pretty good actually.
 Not sure , but that float might be a later one..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Bert

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Re: 750 project
« Reply #12 on: December 05, 2017, 03:30:50 PM »
I was expecting to see brass floats, but I'm not sure what it's supposed to be.

Offline Stev-o

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Re: 750 project
« Reply #13 on: December 05, 2017, 03:47:04 PM »
The date on the tag is 5/72, no 2040907. The parts bike is 11/71.

It's a K2....

http://www.sohc4.net/cb750k-serial-numbers/

Is the motor VIN close? [it wont be exactly the same]
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline Johnie

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Re: 750 project
« Reply #14 on: December 05, 2017, 04:05:19 PM »
That carb is actually pretty dang good. The brass jets and needle will clean up nicely. Rule of thumb is to keep the old brass in the carbs and reuse them as the repops don't keep the correct taper. Just keep the carb brass and you will be good. These early carbs are pretty easy to work on.
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA

Offline Bert

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Re: 750 project
« Reply #15 on: December 05, 2017, 04:12:17 PM »
The motor number is 2048545

The motor number on the parts bike is 2014557

Thanks for the tip on the brash parts for the carbs. Why can't new stuff be up to specs.... sad.


Offline Johnie

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Re: 750 project
« Reply #16 on: December 06, 2017, 08:39:00 AM »
I bet those smashed carbs are the originals along with the mileage. The indicator lights in the gauges were in the 69 - 71 for sure. Yours was close to 72 so got the 71 gauges. Don’t toss those old gauges out as maybe some internals are good.
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA

Offline PeWe

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Re: 750 project
« Reply #17 on: December 06, 2017, 10:21:05 AM »
The sissy bar protected the bike from the roof collapse, right?
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Bert

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Re: 750 project
« Reply #18 on: December 06, 2017, 11:26:06 AM »
I didn't see the roof when it collapsed, but from what Zeek was saying everything else that was around the bike helped suspend the roof. So only the tallest parts were hit. It couldn't have been to bad, the tank and seat were untouched. We get so much dang snow around here, almost every year a building or two collapses.

Offline Johnie

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Re: 750 project
« Reply #19 on: December 06, 2017, 12:44:02 PM »
That bike is known as a "survivor" in more than one way!
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA

Offline Bert

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Re: 750 project
« Reply #20 on: December 06, 2017, 05:48:34 PM »
Plugging along..... cleaning and adding parts, one at a time.

Offline spuds

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Re: 750 project
« Reply #21 on: December 07, 2017, 06:17:22 AM »
So neat that the bike has found its way 'home'.   

It must mean the world to you to have it again.


Offline Bert

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Re: 750 project
« Reply #22 on: December 07, 2017, 02:43:58 PM »
This is my first time using an ultrasonic cleaner on carbs.... and it worked great!

Offline Stev-o

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Re: 750 project
« Reply #23 on: December 07, 2017, 02:51:49 PM »
What cleaner do you have and what cleaning product did you use?

I have been thinking about getting one.
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline Bert

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Re: 750 project
« Reply #24 on: December 07, 2017, 02:59:12 PM »
I picked up a cheap Vevor (model PS-40A) on ebay. And I used Omegaclean diluted 10:1 with water. Let them buzz in there for a few hrs.