Author Topic: Early Sandcast Found......  (Read 93573 times)

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Offline 34barab

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Re: Early Sandcast Found......
« Reply #125 on: March 03, 2021, 02:21:39 PM »
Another one saved!  Congratulations 🎉🍾🎈

I’m curious about the split overflow tube repair.  Can you post a pic of the after?  Thanks.
Current Projects: 1973 CB750K3; 1972 CB350K4; 1980 CX500D;1969 CB750.  Roadworthy: 1971 CB750K1

Offline BenelliSEI

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Re: Early Sandcast Found......
« Reply #126 on: March 03, 2021, 02:52:05 PM »
Another one saved!  Congratulations 🎉🍾🎈

I’m curious about the split overflow tube repair.  Can you post a pic of the after?  Thanks.

I’ll post when I take them off. I used some very fine paper to sand the full length of the pipe in the float bowl. really tried to create a stripe, just along the crack. It was almost top to bottom. Warmed and fluxed it with a small acetylene torch. Tinned gently up and down the crack with some good old 50/50 solder I save for “emergencies”. Ponded a bit at the bottom, but sealed it!
« Last Edit: March 03, 2021, 05:58:03 PM by BenelliSEI »

Offline bwaller

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Re: Early Sandcast Found......
« Reply #127 on: March 03, 2021, 04:59:10 PM »
Don't you love it when a plan comes together!

Offline BenelliSEI

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Re: Early Sandcast Found......
« Reply #128 on: March 03, 2021, 05:38:46 PM »
Don't you love it when a plan comes together!

Glad I can share it with you guys. I am “on cloud nine”! This one may take a while, but I am really looking forward to it. After building my 1970 K0 I thought I might be done. Turns out I’m not!

Offline Stev-o

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Re: Early Sandcast Found......
« Reply #129 on: March 03, 2021, 05:54:16 PM »
Great job!
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline BenelliSEI

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Re: Early Sandcast Found......
« Reply #130 on: March 03, 2021, 06:00:57 PM »
As I was reading through today's reply I was thinking I'd post this was a wahoo day! Ya beat me to it but it still is a Yahoo Wahhoo day! Good to hear it breathes.

Thanks All! Much appreciated! John D.

Offline PeWe

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Re: Early Sandcast Found......
« Reply #131 on: March 03, 2021, 07:19:18 PM »
Good news!
I understand that wonderful feeling when it starts direct and run like music without any trace of reasons to worry about. ;)
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 Terry in Australia

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Re: Early Sandcast Found......
« Reply #132 on: March 04, 2021, 12:41:38 AM »
Good job John, any time bringing a bike back to life doesn't require a full rebuild, is a bonus! ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline BenelliSEI

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Re: Early Sandcast Found......
« Reply #133 on: March 04, 2021, 06:16:54 AM »
Good job John, any time bringing a bike back to life doesn't require a full rebuild, is a bonus! ;D

Yep.... Low mileage, so really not surprised it so quiet and strong. It does have lots of head gasket staining, so top end for sure.
« Last Edit: March 04, 2021, 07:11:03 AM by BenelliSEI »

Offline BPellerine

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Re: Early Sandcast Found......
« Reply #134 on: March 04, 2021, 06:35:18 AM »
you are making it look easy!
1978 CB 750K ard and webers
another anfob

Offline BenelliSEI

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Re: Early Sandcast Found......
« Reply #135 on: March 04, 2021, 01:18:55 PM »
Another one saved!  Congratulations 🎉🍾🎈

I’m curious about the split overflow tube repair.  Can you post a pic of the after?  Thanks.

Here’s the float bowl repair (started pulling it down today). Bit of a “lump” at the bottom, but the smooth tin up the pipe is completely sealing the split. Nothing loose, so just left it and works great.

Offline Terry in Australia

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Re: Early Sandcast Found......
« Reply #136 on: March 04, 2021, 05:40:07 PM »
Good job John, any time bringing a bike back to life doesn't require a full rebuild, is a bonus! ;D

Yep.... Low mileage, so really not surprised it so quiet and strong. It does have lots of head gasket staining, so top end for sure.

Good job John. If it's been sitting so long there's probably some surface rust on everything above the oil level in the pan, but it'll wash off in the hot oil after being ridden, so drop your oil and filter after the first few hundred miles or so and put fresh oil and filter in, and you should be good to go. I was surprised at how dirty my oil was after 1000 miles considering that I'd built my engine from a set of perfectly clean bare cases and all of the used parts (crank, gearbox etc) looked pretty clean too. ;D   
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline BenelliSEI

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Re: Early Sandcast Found......
« Reply #137 on: March 04, 2021, 06:23:01 PM »
Terry.... you are right! Today I put 2.5 litres of fresh oil, and installed a new filter. Put the big shop fan up front and ran it for a good 20-25 minutes. Rev’e it a bit and let it idle, set the carb sync at idle. Super smooth and the pipes stopped shedding carbon and rust! Drained the hot oil and it was pretty dark! 70-75 psi oil pressure all the time. Delighted.

Offline Terry in Australia

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Re: Early Sandcast Found......
« Reply #138 on: March 04, 2021, 06:55:39 PM »
That's great John, I see so many folks on youtube fire up an old car or bike that's sat for many years and ride/drive it home (sometimes hundreds of miles) without dropping the oil and filter even once, and I shudder at what damage is happening internally. ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline PeWe

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Re: Early Sandcast Found......
« Reply #139 on: March 04, 2021, 09:45:07 PM »
Has the bike been stored in room temperature during all years?

Open clutch cover and check clutch steel basket if rusty.
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 Terry in Australia

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Re: Early Sandcast Found......
« Reply #140 on: March 05, 2021, 01:57:24 AM »
Has the bike been stored in room temperature during all years?


Looking at the rust and corrosion on it in John's original pics Per, I'd say no. ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline BenelliSEI

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Re: Early Sandcast Found......
« Reply #141 on: March 05, 2021, 05:01:58 AM »
Has the bike been stored in room temperature during all years?

Open clutch cover and check clutch steel basket if rusty.

Before I pull the engine, I usually “knock” all the JIS screws loose. Then all the covers will come off (after a wash). The bike was never left outside, so probably never wet, but some condensation? Inside of the tank is remarkably clean, so not much. Definitely be checking that clutch!

Offline PeWe

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Re: Early Sandcast Found......
« Reply #142 on: March 05, 2021, 06:19:20 AM »
My K6 was stored in a not heated dry barn for 19 years.  Cold in winter, warmer summertime.
No specific rust inside engine except valve seats, a little on valves and corroded piston top. Bores OK.

I rode it to barn and left it. Spray oil mist inside plugs might have avoided some seat pitting. A head job fixed it.

Climate here not normally humid
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 Prospect

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Re: Early Sandcast Found......
« Reply #143 on: March 05, 2021, 12:37:10 PM »
Hey John.

Isn't it an amazing feeling to get an old bike running! I think it's even more exciting than riding it. Excellent progress so far.

Does your sandcast have smooth oil lines or the later ones like on all cb750's? I can't tell from the picture and I can't recall when they switched over. I've never actually seen smooth lines and have never seen them pop up for sale.
Current Bikes

1969 CB750  Sandcast #256
1971 CB750K1
1972 CB750K1
1975 CB400F
1975 GL1000 Goldwing
1954 Harley Davidson Panhead
1957 Harley Davidson Panhead

Toronto Canada

Offline BenelliSEI

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Re: Early Sandcast Found......
« Reply #144 on: March 05, 2021, 01:57:10 PM »
Hey John.

Isn't it an amazing feeling to get an old bike running! I think it's even more exciting than riding it. Excellent progress so far.

Does your sandcast have smooth oil lines or the later ones like on all cb750's? I can't tell from the picture and I can't recall when they switched over. I've never actually seen smooth lines and have never seen them pop up for sale.

They look like all my other lines, so probably not. It also looks like it always had the finned oil filter can, as well. I am pretty delighted. When I ran it with fresh oil, I sync’d the carbs at idle and it sounded perfect...... the original pipes have a few holes on the underside, but I’m pretty sure I can save them too!
« Last Edit: March 05, 2021, 01:59:17 PM by BenelliSEI »

Offline Terry in Australia

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Re: Early Sandcast Found......
« Reply #145 on: March 05, 2021, 04:37:35 PM »
A head job fixed it.

Very true Per, a head job fixes everything, I reckon! ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline BenelliSEI

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Re: Early Sandcast Found......
« Reply #146 on: March 05, 2021, 05:55:02 PM »
A head job fixed it.

Very true Per, a head job fixes everything, I reckon! ;D

🤣

Offline PeWe

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Re: Early Sandcast Found......
« Reply #147 on: March 06, 2021, 12:22:34 AM »
A head job fixed it.

Very true Per, a head job fixes everything, I reckon! ;D


Sometimes a stiff GT fix head issues too! ;D
With ice and lemon....
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 BenelliSEI

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Re: Early Sandcast Found......
« Reply #148 on: March 08, 2021, 06:49:38 PM »
Scored a beautiful, used, original “2 hole” rear fender today! Arrived by post, undamaged. Test fit and photos tomorrow. Delighted!

Offline BenelliSEI

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Re: Early Sandcast Found......
« Reply #149 on: March 08, 2021, 06:57:35 PM »
Open to suggestions: I’ll be down to the bare frame in a few days. It appears undamaged, no scrapes, gouges or dings. Some of the “Factory” welds are just plain terrible, but “original”. You’d think after 1,250 attempts, they might have got the hang of it!

I do have to remove the remains of a luggage rack that was welded to the rear foot peg/ pipe mounts, but fortunately that fellow was clueless. There is zero weld penetration so may just pull off.

Planning to blast the battery box, centre stand and side stand and likely have them powder coated, along with a few small brackets and bits. What about the frame? It’s too far done to just “polish and touch up”. Paint? Today’s water based? Epoxy?? Mmmmm.
« Last Edit: March 08, 2021, 07:00:23 PM by BenelliSEI »