Honda-SOHC

SOHC.co.uk Forums => Project Board => Topic started by: JamesH on February 11, 2020, 07:31:11 PM

Title: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 07:31:11 PM
Evening all. Just about to start final assembly of my sandcast #4645, so thought I’d share progress in a new thread.

Will post pictures as-found, and at various stages of the restore...

For now, here she is ‘as-found’ near Denver, Colorado:

(https://uploads.tapatalk-cdn.com/20200211/bdf92bdeb966406bce5f02d296685988.jpg)


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Title: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 07:53:23 PM
More pics as found.

The bike was taken off the road in the late 70’s.

The engine fitted when the bike was found (as pictured) was a later 6xxx sandcast which was apparently swapped into the bike very early in its life.

The original #4615 engine suffered from chain failure within weeks of being sold to the original owner (a fate suffered by many early 750’s).

Fortunately, the original engine was sitting in the field next to the bike when found...so came with the bike when I purchased her back in 2018

My plan was to fix and re-unite the bike with its original engine - as you’ll see in the coming posts this was a bit more of a challenge than expected.

Had it not been for Graham’s tenacity, skill and sheer bloody-mindedness (and me prodding from afar) this would never have happened..


(https://uploads.tapatalk-cdn.com/20200211/956f8c20440ca6cad1ef8400ce57125b.jpg)

(https://uploads.tapatalk-cdn.com/20200211/322bd83670ab48c530ded2cf10a91e74.jpg)(https://uploads.tapatalk-cdn.com/20200211/4f28e2331799e8fc06a8b7f712643afd.jpg)(https://uploads.tapatalk-cdn.com/20200211/a3eff64349260cf2af04b1b01faae23f.jpg)

(https://uploads.tapatalk-cdn.com/20200211/32ae57e06be1f82236aba727daa78b6a.jpg)(https://uploads.tapatalk-cdn.com/20200211/b5dbde8c2f6a52b4171f72f8edbbb35c.jpg)(https://uploads.tapatalk-cdn.com/20200211/bddd9807309ad023a9fb93816f4fa885.jpg)(https://uploads.tapatalk-cdn.com/20200211/ead3cb048761a2a3ed6f59ec8c54a6b6.jpg)


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Title: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 08:01:05 PM
In Graham’s workshop the full horror story is revealed....

WTF was I thinking lol...??

Look away now..

(https://uploads.tapatalk-cdn.com/20200211/aafd7f2fff3bd51dfaca7e0c4140c672.jpg)(https://uploads.tapatalk-cdn.com/20200211/26a216f315b7bda8dc9d65a18e4e2bb5.jpg)(https://uploads.tapatalk-cdn.com/20200211/15174bd3ab950e2ba8b0f35251d6eae7.jpg)(https://uploads.tapatalk-cdn.com/20200211/04adcd7a4c91d9a17d0215208818f139.jpg)(https://uploads.tapatalk-cdn.com/20200211/03af032df82c6221f0775af96f466b7b.jpg)(https://uploads.tapatalk-cdn.com/20200211/192c8d93f0e629ea6e4bf2d272dd7ec7.jpg)(https://uploads.tapatalk-cdn.com/20200211/8f947d91490fbac74005b8e1a802617f.jpg)(https://uploads.tapatalk-cdn.com/20200211/c70264c6dbf0df7c696cc9aa1e5d86cb.jpg)


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Title: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 08:09:45 PM
After hours and hours of reconstructive TIG induced surgery from Graham, we have a viable pair of engine cases again...

Graham made me sign a contract never to send him an engine like this again lol.

(https://uploads.tapatalk-cdn.com/20200211/864637c81b503114c76bf63957c0a9ad.jpg)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 08:21:31 PM
After a serious amount of hard Graft from Graham...

(https://uploads.tapatalk-cdn.com/20200211/3a20c78f5fb9a178a2de43dd86011a5b.jpg)(https://uploads.tapatalk-cdn.com/20200211/a7da0c6d44a76e8af16c296743c789f9.jpg)(https://uploads.tapatalk-cdn.com/20200211/d8536a8493a0b9106c19c120eef8946e.jpg)(https://uploads.tapatalk-cdn.com/20200211/105bfbd170ede4716dfa9552dc30eb1c.jpg)(https://uploads.tapatalk-cdn.com/20200211/94c24324ad03d67dde4de948d917e471.jpg)(https://uploads.tapatalk-cdn.com/20200211/f8635963f86fea2aac46540c6d39c911.jpg)(https://uploads.tapatalk-cdn.com/20200211/05a16436afab7fc8cae01e13e314d4eb.jpg)


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Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 08:27:46 PM
The engine and rear wheel were removed before I put the bike in the workshop for the initial strip..

The aim with this bike is to restore and refurbish as much as possible, given its rarity and the effort to reunite the bike with its original engine...

(https://uploads.tapatalk-cdn.com/20200211/0c9e92a5b14d4d682eff627ed48674ff.jpg)(https://uploads.tapatalk-cdn.com/20200211/e1120b13de6517903ad7c8738d5bbd5a.jpg)(https://uploads.tapatalk-cdn.com/20200211/638af69cf26cebe47864bc31d36d78af.jpg)(https://uploads.tapatalk-cdn.com/20200211/114fb7a65895c5ebd4d8d820d179698e.jpg)(https://uploads.tapatalk-cdn.com/20200211/9caf67c97cfb03141d6367b5c452be1c.jpg)(https://uploads.tapatalk-cdn.com/20200211/529d120287bedcac1e6146424a321558.jpg)(https://uploads.tapatalk-cdn.com/20200211/2c4ca5ebe97dc39266f5cde66d0c7011.jpg)(https://uploads.tapatalk-cdn.com/20200211/288d5e94095db01515d9bb2c7f944b85.jpg)(https://uploads.tapatalk-cdn.com/20200211/b785106d5e5712af660245db20b725bc.jpg)


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Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 08:32:23 PM
All the correct original features, 8 bolts everywhere, loads of work ahead...
(https://uploads.tapatalk-cdn.com/20200211/f927e4d4f2f9a31048f6176d5d1ac3f1.jpg)(https://uploads.tapatalk-cdn.com/20200211/2b662a93567174e75b9a4b676924beb8.jpg)(https://uploads.tapatalk-cdn.com/20200211/0e78422b69407f76de3e88973047442a.jpg)(https://uploads.tapatalk-cdn.com/20200211/3d83ec0235f8ae20864d37c798d3392e.jpg)(https://uploads.tapatalk-cdn.com/20200211/a67bf5ef1f469c16f9516bd641fca195.jpg)(https://uploads.tapatalk-cdn.com/20200211/d35e175837d077aeda5e6b4951d730b8.jpg)(https://uploads.tapatalk-cdn.com/20200211/ff1d50a69fb0cdcc1bdf9b9e374032d1.jpg)


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Title: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 08:36:37 PM
After stripping, the frame was sent off to Maidstone Motoliner for a full alignment check. Tommy has done lots of 750’s for me in the past and is great to work with. The photo below is one of my previous bikes in the Motoliner jig.

(https://uploads.tapatalk-cdn.com/20200211/65b1545d915d0ebff46a86a15b50ec8e.jpg)

The frame was stripped, zinc primed and 2k painted along with the other cycle parts..

(https://uploads.tapatalk-cdn.com/20200211/4817e8a193eedaad4921055cfd9840c1.plist)

Ready for its original engine (the first time they will have been back together in over 50 years)...

(https://uploads.tapatalk-cdn.com/20200211/d9c12fdf8ba5a0a74e998bc8ade46840.jpg)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 08:46:17 PM
Frame built back up to a stage ready to accept the engine again.

All of the original fasteners were stripped and re-zinc’d.

(https://uploads.tapatalk-cdn.com/20200211/77c491f3d33fe49fb09ae531375593b3.jpg)(https://uploads.tapatalk-cdn.com/20200211/3b6dc82ced7fb5325ad696d55ab4e7bb.jpg)(https://uploads.tapatalk-cdn.com/20200211/7d1c609ec39cba14cad8f0c41a6fc727.plist)(https://uploads.tapatalk-cdn.com/20200211/0b0c24ac176b249e83fe574fd7d4dbbd.plist)(https://uploads.tapatalk-cdn.com/20200211/1bab8f2677610c3964cb1ec7d10fc9c2.plist)(https://uploads.tapatalk-cdn.com/20200211/fd82b602f3d6bd8380595e9fccc4856b.plist)(https://uploads.tapatalk-cdn.com/20200211/98b2936349a1c9824078fdea543c032d.plist)(https://uploads.tapatalk-cdn.com/20200211/cdb773ade65494db28384ead9ff08448.plist)


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Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Laverda Dave on February 11, 2020, 09:11:35 PM
Amazing work James (and Graham). That bike was seriously crusty when you bought it!
Is the engine back in the frame now, when we're the last photos taken and when do you think you'll be riding it?
Keep the progress photos coming👍
Title: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 09:16:04 PM
These photos were taken yesterday after the engine was finally reunited with the frame...

(https://uploads.tapatalk-cdn.com/20200211/d23137a8d4ce9b63eccf01890348dd46.jpg)(https://uploads.tapatalk-cdn.com/20200211/e66684c67bd9c0ad076e6f48a08fab8a.jpg)

(https://uploads.tapatalk-cdn.com/20200211/109b84c7432b7a51de5ff9d31d7902ac.jpg)(https://uploads.tapatalk-cdn.com/20200211/3bf8adc3e8d061b884d0333dfe80cfe8.jpg)


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Title: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 09:26:42 PM
Amazing work James (and Graham). That bike was seriously crusty when you bought it!
Is the engine back in the frame now, when we're the last photos taken and when do you think you'll be riding it?
Keep the progress photos coming
Thanks Dave. The previous post was from yesterday’s progress. Will be updating the thread over the next 6-8 weeks as the build progresses. Aim is to have her back on the road in April...


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Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Nurse Julie on February 11, 2020, 09:32:18 PM
Quote 'Graham made me sign a contract never to send him an engine like this again lol.'
Ah yes, not seen that come back in the post yet James 🤔 🤔🤔🤣🤣🤣🤣🤣🤣🤣🤣
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 09:34:37 PM
Quote 'Graham made me sign a contract never to send him an engine like this again lol.'
Ah yes, not seen that come back in the post yet James
Ha ha - it was a verbal contract lol


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Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Nurse Julie on February 11, 2020, 09:37:16 PM
Quote 'Graham made me sign a contract never to send him an engine like this again lol.'
Ah yes, not seen that come back in the post yet James
Ha ha - it was a verbal contract lol


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Ah, OK, suits me, less paperwork for me to sort 😊😊😊😊
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 10:25:50 PM
Quote 'Graham made me sign a contract never to send him an engine like this again lol.'
Ah yes, not seen that come back in the post yet James
Ha ha - it was a verbal contract lol


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Ah, OK, suits me, less paperwork for me to sort



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Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Andrew-S on February 11, 2020, 10:55:00 PM
Stunning work.

I just love threads like this which raises what would have otherwise been a dead bikes from the grave. I'll be following progress with keen interest - always inspiring!

Title: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 11, 2020, 11:02:37 PM
Stunning work.

I just love threads like this which raises what would have otherwise been a dead bikes from the grave. I'll be following progress with keen interest - always inspiring!
Thanks Andrew, I appreciate it.
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Bryanj on February 12, 2020, 01:03:15 AM
Great work, am i tight that engine is lower number than frame?
Title: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 12, 2020, 05:51:04 AM
Great work, am i tight that engine is lower number than frame?
Yes Brian. I’ve had both higher and lower number pairs on sandcasts in the past..generally the engine number is higher...but it’s pretty random to be honest. During early production I think they fairly randomly selected engines from the line as they became available after quality control release..photo below is an excerpt from the Sandcast Owners public registry....I can’t see any discernible pattern..

(https://uploads.tapatalk-cdn.com/20200212/1599c6df533e68567ac4fcd51006c026.plist)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 12, 2020, 09:46:27 AM
Was looking at the frame again last night and noticed I’d missed a couple of ‘notches’ that the PO had made to the air box frame mount tabs. Annoying, but not worth stripping / repairing as it’s pretty hidden away under the tank (I’m telling myself it’s part of the ‘history’ of the bike lol).
(https://uploads.tapatalk-cdn.com/20200212/c220b2e00b0ef5c0fe23e7a77ccf1402.jpg)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Moorey on February 12, 2020, 04:38:50 PM
Nobody will see it at 100mph James.  ;)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 12, 2020, 05:47:36 PM
Nobody will see it at 100mph James.  ;)
Lol, true!
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 13, 2020, 10:07:08 PM
Made some good progress over the past couple of days.

Centre stand, rear brake lever/mechanism and swing arm fitted, battery box and tool tray fitted, new rear shocks on, wiring loom loosely fitted, coils fitted, horn fitted, rider foot rests built and fitted, gear lever fitted, Honda logo on generator cover in-filled black, swing arm and headstock decals fitted.

She starting to show how good she’ll hopefully look when finished.

Paint set is off with Menno in Germany being painted (tank should be back from the chemical strippers tomorrow hopefully).

Both wheels have been rebuilt (original rims were rechromed several months ago before my supplier stopped doing them). Photos of those to follow (rolled rear rim is a beauty).

Rear sprocket carrier rebuilt with new bearing / retainer.

Exhaust collars have been rechromed and look superb, as do the exhaust spigots which have been refitted to the engine.

Anyway, enough waffling, here are some more pictures...

(https://uploads.tapatalk-cdn.com/20200213/fb14b638ead324f144593d9270c7f2be.jpg)(https://uploads.tapatalk-cdn.com/20200213/abca6832e8d42d207a1aec011be84a5d.jpg)(https://uploads.tapatalk-cdn.com/20200213/100e75f82277502ad8ad24e6b1d2895e.jpg)(https://uploads.tapatalk-cdn.com/20200213/8ffa35bdc5753531d39ab6f6ac046416.jpg)(https://uploads.tapatalk-cdn.com/20200213/4dd477322fcc33e4dd86d0bebc2d1fd9.jpg)(https://uploads.tapatalk-cdn.com/20200213/1eb44f146a26a1eabd1f679a6f821b5a.jpg)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 13, 2020, 10:16:16 PM
(https://uploads.tapatalk-cdn.com/20200213/222954f11b29c53b5eb60e379b2c0612.jpg)(https://uploads.tapatalk-cdn.com/20200213/30efb9b0d86fdc84624d2c702a7d6bd0.jpg)(https://uploads.tapatalk-cdn.com/20200213/37fe2e3963011861c9846d8a1d4ee213.jpg)(https://uploads.tapatalk-cdn.com/20200213/3d1dc39b6c15860584fd168fc9fa5105.jpg)(https://uploads.tapatalk-cdn.com/20200213/d37a45f0d1ac18d7d22b42f2ef237f46.jpg)(https://uploads.tapatalk-cdn.com/20200213/7fc450b460fe4d207e9a67b06dc7de57.jpg)(https://uploads.tapatalk-cdn.com/20200213/3bf07d7becfe840ba81c6a47c6351fb0.jpg)(https://uploads.tapatalk-cdn.com/20200213/7eda2fec39a01afc4df89d6739f8b981.jpg)(https://uploads.tapatalk-cdn.com/20200213/638b379f2fe8b0185c916f9b0494e1c9.jpg)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 13, 2020, 10:27:44 PM
(https://uploads.tapatalk-cdn.com/20200213/3390cd4784f67e09032a1c309dbffef4.jpg)(https://uploads.tapatalk-cdn.com/20200213/a6e2eab2fab35f7e3f15139b080624c6.jpg)(https://uploads.tapatalk-cdn.com/20200213/f8a02cb6d50d5dee9d46e8383c0ecf5f.jpg)(https://uploads.tapatalk-cdn.com/20200213/74ce1fd1f0c5722226af740de51ce17d.jpg)(https://uploads.tapatalk-cdn.com/20200213/39e10b685cf1be65ee0ed0445760a796.jpg)(https://uploads.tapatalk-cdn.com/20200213/4ea7c4ee6c49f067d396eb8e6326b0e0.jpg)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: MCTID on February 13, 2020, 10:43:02 PM
Yuk....the crankcases look a bit rough ! Before I bought one, I think I would have waited a year or so until Honda changed over to Die Casting them !

(Tee hee)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: paul G on February 14, 2020, 08:21:52 AM
Looking good as usual James  :)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 14, 2020, 08:27:25 AM
Yuk....the crankcases look a bit rough ! Before I bought one, I think I would have waited a year or so until Honda changed over to Die Casting them !

(Tee hee)

Ha ha yeah, I may have to get the sander out and smoothe them off..

Looking good as usual James  :)
Thanks Paul.
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Trigger on February 14, 2020, 09:19:20 AM
I can't believe that you posted the pictures of that hole in the cases. I have just recovered from months of flashbacks and spent a small fortune on a psychiatrist to get my brain back in order  :o

A repair like this was even a challenge for me, it was not a case of wave a magic welding rod about and everything fell in to place. What happens when the chain whiplashes on the sprocket to make that size hole. The engine is hot and alloy of any type will reform in to a different shape. Think of a bit of hot alloy been hit by the force of a sledge hammer and you can imagine what the result would be  ???
First a jig was made from a 27mm plate so that the engine cases could be bolted down and measurements could be taken. Once I was happy that the cases are within spec ( not found in a manual ). You will have to try and fit the gear box, kickstart shaft and the final drive, while it is still bolted to the plate. Once you have worked out that your welding is clear of the gear box, you cross your fingers and hope for the best.

I lost count of how many times I removed and fitted the gearbox. As heat from the welding distorts alloy very easy. The welding took about 20 days, doing a little at a time, walking away for it to cool. Once all the welding was done the mating surface had to be milled taking a flat point from other parts of the case surfaces.

Job done after a little grinding and sanding but no, it was a little out of line on one of the gearbox bearing housings and a little line boring had to be called for before, everything lined up and fitted correctly.
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Spitfire on February 14, 2020, 10:22:28 AM
What a fantastic journey, from it's "final" resting place to where it is now, pretty unbelievable, just shows what hard work, knowledge and skill can do.
Great to see another one being resurrected.

Cheers

Dennis
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 14, 2020, 12:05:24 PM
There is no way this bike would be going back together in its correct, original form had it not been for Graham. All I can say is sorry, and thank-you mate :-)

I can't believe that you posted the pictures of that hole in the cases. I have just recovered from months of flashbacks and spent a small fortune on a psychiatrist to get my brain back in order  :o

A repair like this was even a challenge for me, it was not a case of wave a magic welding rod about and everything fell in to place. What happens when the chain whiplashes on the sprocket to make that size hole. The engine is hot and alloy of any type will reform in to a different shape. Think of a bit of hot alloy been hit by the force of a sledge hammer and you can imagine what the result would be  ???
First a jig was made from a 27mm plate so that the engine cases could be bolted down and measurements could be taken. Once I was happy that the cases are within spec ( not found in a manual ). You will have to try and fit the gear box, kickstart shaft and the final drive, while it is still bolted to the plate. Once you have worked out that your welding is clear of the gear box, you cross your fingers and hope for the best.

I lost count of how many times I removed and fitted the gearbox. As heat from the welding distorts alloy very easy. The welding took about 20 days, doing a little at a time, walking away for it to cool. Once all the welding was done the mating surface had to be milled taking a flat point from other parts of the case surfaces.

Job done after a little grinding and sanding but no, it was a little out of line on one of the gearbox bearing housings and a little line boring had to be called for before, everything lined up and fitted correctly.
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 14, 2020, 04:47:02 PM
What a fantastic journey, from it's "final" resting place to where it is now, pretty unbelievable, just shows what hard work, knowledge and skill can do.
Great to see another one being resurrected.

Cheers

Dennis
Thanks Dennis.
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Laverda Dave on February 14, 2020, 04:49:41 PM
Great stuff James.  Are you actually going to be riding this gem or dedicating it to a museum for long term loan?
I must be blind as I am unable to see the photo with the hole in the crankcase?
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 14, 2020, 04:55:25 PM
Great stuff James.  Are you actually going to be riding this gem or dedicating it to a museum for long term loan?
I must be blind as I am unable to see the photo with the hole in the crankcase?

Dave - was in one of the earlier posts. Hope you're sitting down.....

I'll definitely be riding this one....

(https://uploads.tapatalk-cdn.com/20200211/03af032df82c6221f0775af96f466b7b.jpg)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Laverda Dave on February 14, 2020, 06:19:56 PM
Oh dear, and I thought that was all part of the air cooled motor!
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: philward on February 14, 2020, 09:42:50 PM
Great stuff James.  Are you actually going to be riding this gem or dedicating it to a museum for long term loan?
I must be blind as I am unable to see the photo with the hole in the crankcase?

Dave - was in one of the earlier posts. Hope you're sitting down.....

I'll definitely be riding this one....

(https://uploads.tapatalk-cdn.com/20200211/03af032df82c6221f0775af96f466b7b.jpg)
Oops - that a hole! Wouldn't believe that could be repaired
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Bryanj on February 14, 2020, 10:02:18 PM
Like i always say anything is possible with time, money and a good engineer who really knows his stuff.
Just a problem getting all those in the same place at the same time!!!!
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: UK Pete on February 15, 2020, 07:46:40 PM
Amazing progress James, and trigger

Sent from my SM-G950F using Tapatalk

Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 16, 2020, 01:50:56 PM
Like i always say anything is possible with time, money and a good engineer who really knows his stuff.
Just a problem getting all those in the same place at the same time!!!!
No wrong there Bryan. As I’ve said before, without Graham agreeing to take this on I’d have been stuffed.
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 16, 2020, 01:51:13 PM
Amazing progress James, and trigger

Sent from my SM-G950F using Tapatalk
Cheers Pete - hope you’re well mate. J
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Bryanj on February 16, 2020, 02:20:35 PM
Thats what i meant Graham is a good engineer who knows hos stuff, anything 750 i defer to him!
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Johnwebley on February 19, 2020, 11:10:03 AM


    here is another in under 6 minutes


   https://silodrome.com/honda-cb750-sandcast-restoration-timelapse-short-film/
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: paul G on February 19, 2020, 12:28:02 PM


    here is another in under 6 minutes


   https://silodrome.com/honda-cb750-sandcast-restoration-timelapse-short-film/
What's with the Red enamel  ??? got to say he laces and trues a wheel a bit quicker than me  ;D
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 19, 2020, 11:16:35 PM
Bit more progress past couple of days. Still plenty to do but slowly working through it.

Latest ‘highlights’

Oil tank cleaned internally, repainted externally, test fitted
Front brake splitter stripped, sensor cleaned, refitted
Electrical panel assembled / refitted
Battery fitted
Forks stripped, lowers polished, cleaned and reassembled with new stanchions, seals, Honda gaitors
Wheel bearing replaced front and rear
Rear sprocket carrier test assembled and sprocket plate refinished
Wheels ready to fit..
Handlebar controls stripped, repainted and re assembled

Going to pause for a while whilst I wait for Menno to finish the paintwork

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Title: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 19, 2020, 11:19:04 PM
Tank stripped - now time for Menno to work his magic..

(https://uploads.tapatalk-cdn.com/20200219/fa0d0744c19ed24163d785e4b0a49e8e.jpg)(https://uploads.tapatalk-cdn.com/20200219/1a6ac546bffaf5aa2c6697aa4fa772af.jpg)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 19, 2020, 11:20:57 PM
(https://uploads.tapatalk-cdn.com/20200219/d0a116d01a39e6f95e79336784119544.jpg)(https://uploads.tapatalk-cdn.com/20200219/cd89cfc76713d227e9b117ca9d9dff36.jpg)(https://uploads.tapatalk-cdn.com/20200219/a2dac563e8a8959740ff73bc0a33b483.jpg)(https://uploads.tapatalk-cdn.com/20200219/d4a08f7e6bb4c17e87a9ff10fb627a85.jpg)(https://uploads.tapatalk-cdn.com/20200219/9f5c6e776af67bb770a8b9773cd714a8.jpg)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Laverda Dave on February 20, 2020, 11:09:08 AM
Those tyres remind me of the late 60's  8)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: AshimotoK0 on February 20, 2020, 12:12:29 PM
Absolutely stunning .. as ever James...I saw those cases at Trigg & Julies mid-surgery and it looked a mammoth task to fix them.  Confused with sprocket guard on rear wheel though ... I thought that they came in with the K1...having said that I am not that familiar with the sandcast model but my 10/69 UK diecast was never fitted with one AFAIK.
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: MrDavo on February 21, 2020, 01:00:21 PM
Amazing what can be saved if it's worth saving enough. Look at Bluebird, after they fished it out of Coniston Water, where possible they ironed out all the creases left by its 300 mph crash, rather than use new unoriginal alloy, which would have been a much easier option. I read an article about an original lightweight (alloy bodied) E type Jaguar, one of only 12 built, that had been rolled into a small ball in a fatal crash decades ago, and abandoned in a container at the back of a French race circuit - it's now back on the road, again now worth doing at several million pounds a pop.

I remember getting up close and personal with the engine on my very early CB750, which I owned as a student, when I gave it an oil change (Duckhams), and being frankly disappointed with the very poor finish of the castings, I was surprised that Honda could have left it looking that rough.

Who knew that, one day, that rough finish would make it so desirable? - I wish to *&%$ I had, I swapped it for a £600 Norton. My first salary after uni was £2,000, so one day that sandcast would be worth, say, 15 years wages.
Title: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 21, 2020, 03:16:53 PM
Thanks Ash and Dave for your comments.

I thought I’d posted photos of the double-cut fender before/after but obviously hadn’t.

I had this repaired and replated by Derby Chrome - cost was ~£400 but as the old adage goes, sadly you pay for what you get...

Still - it feels like a crazy amount to spend refurbishing a single item, but when you consider the skill and effort that goes into repairing one of these you can understand why.

Yamiya do sell a repro double cut front fender, but by the time you’ve paid shipping and import duty you’re looking at ~£1200 for one

(https://uploads.tapatalk-cdn.com/20200221/b02be945d2318888867d5f1573ef37cb.jpg)(https://uploads.tapatalk-cdn.com/20200221/5ee6ee10ba7cf66367779ab09f71da2e.jpg)(https://uploads.tapatalk-cdn.com/20200221/90d91c3ead44b42b707d968f4d4748cd.jpg)(https://uploads.tapatalk-cdn.com/20200221/c49c847bad78d45912130336ebbda3fe.jpg)(https://uploads.tapatalk-cdn.com/20200221/bda3a5d1b8d03a107544ec54a47256d8.jpg)

(https://uploads.tapatalk-cdn.com/20200221/ce4197db8555fe2faf8f75f0322961d5.jpg)(https://uploads.tapatalk-cdn.com/20200221/7d288b1f72abda39d92783998c48013e.jpg)(https://uploads.tapatalk-cdn.com/20200221/bb849a69188fb45a30a44fdfccd81d49.jpg)(https://uploads.tapatalk-cdn.com/20200221/076bb37329616f1c22fb00de1adf3541.jpg)
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Andrew-S on February 21, 2020, 04:30:38 PM
Excellent job by Derby Plating James, I've used them for some rare Triumph TR parts as their work is top notch!
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 28, 2020, 05:46:07 PM
Back end pretty much completed now. Just waiting for some misc parts.

Oil tank finished with freshly refurbished oil lines.

Started on the carbs yesterday evening, and have the seat base to refurbish as well.

Whilst I’m waiting for the paint set I’ve decided to roll the next project into the workshop to work on in parallel.

(https://uploads.tapatalk-cdn.com/20200228/79581218e2da88251d20f7cf36b003c9.jpg)(https://uploads.tapatalk-cdn.com/20200228/e098bfd5b9526c5c23b62366d864aa69.jpg)(https://uploads.tapatalk-cdn.com/20200228/480d031d9d7a741d5dd93ef7f962960a.jpg)(https://uploads.tapatalk-cdn.com/20200228/64771ae005652de393aa456a5c8abc82.jpg)(https://uploads.tapatalk-cdn.com/20200228/a88f6b98189c5df748e37fa1b11d48bd.jpg)

Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Laverda Dave on February 28, 2020, 06:09:28 PM
Looking better with every post James👍
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Andrew-S on February 28, 2020, 06:48:31 PM
Looking better with every post James👍

👍Yep, +1
 
James,

I notice both the exhaust support bolts are protruding probably because the rear wheel is fitted, but is this bolt also an interference fit? The reason I ask is that I have the rear wheel and right side exhaust set off at the moment and the support bolt is a tight fit despite cleaning and WD40, so wondered whether it was (can't see why it would be?) before I use my trusty rubber mallet and lube! 

What tires and chain have gone for?

Cheers, Andrew
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Laverda Dave on February 29, 2020, 10:27:33 AM
James,  What is the bike behind the sandcast (I know its a 750), I notice it has a gauge beside the missing side panel, was it a turbo in a previous life?  Is this the next resto?
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 29, 2020, 10:56:17 AM
Looking better with every post James

Yep, +1
 
James,

I notice both the exhaust support bolts are protruding probably because the rear wheel is fitted, but is this bolt also an interference fit? The reason I ask is that I have the rear wheel and right side exhaust set off at the moment and the support bolt is a tight fit despite cleaning and WD40, so wondered whether it was (can't see why it would be?) before I use my trusty rubber mallet and lube! 

What tires and chain have gone for?

Cheers, Andrew
The exhaust hanger pins are a semi-loose fit in my experience Andrew - certainly not an interference fit. However, getting them through the hangers once the exhausts are fittted all depends on the accuracy of manufacture of the pipes. I’ve found Yamiya’s HM300’s and genuine Honda HM300’s are a good fit in that regard. So a bit of grease and a rubber mallet and you’ll be fine.

Tyres are Continental RB2/K112. Just a standard OEM chain.
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: JamesH on February 29, 2020, 10:57:24 AM
James,  What is the bike behind the sandcast (I know its a 750), I notice it has a gauge beside the missing side panel, was it a turbo in a previous life?  Is this the next resto?
The gauge is an original Bowman products on-bike carb sync tool Dave. Pointless, but kind of cool.

The bike is a 2xxx sandcast - the next project...
Title: Re: 1969 CB750 Sandcast #4645 restoration
Post by: Andrew-S on February 29, 2020, 01:24:07 PM
The exhaust hanger pins are a semi-loose fit in my experience Andrew - certainly not an interference fit. However, getting them through the hangers once the exhausts are fittted all depends on the accuracy of manufacture of the pipes. I’ve found Yamiya’s HM300’s and genuine Honda HM300’s are a good fit in that regard. So a bit of grease and a rubber mallet and you’ll be fine.

Tyres are Continental RB2/K112. Just a standard OEM chain.

Thanks for the info James, they're Honda HM300's so maybe it's me as I know what I'm like with a rubber mallet in hand!  ::)

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