Topic: Early Sandcast Found......

[BenelliSEI]

Just hope it does not get in the rolled part , and then not come out..

Yikes.... good point.

[Terry in Australia]

Just hope it does not get in the rolled part , and then not come out..

Yikes.... good point.

Nope, won't hurt it John, I've done plenty, Phoshoric acid just dries out and becomes phosphor, a rust preventative, and won't eat thru the metal. Here's some "food" for thought: https://www.britannica.com/science/phosphoric-acid

[Terry in Australia]

Oh, and I haven't installed your switches, or the OEM K0 handlebars etc on my K0 yet, so if you want them back for your Sandy, let me know? I just bought 3 more bikes, so won't mind some money right now.....

[PeWe]

Tasty too?
"It serves as an acidic, fruitlike flavouring in food products"

[Terry in Australia]

Tasty too?
"It serves as an acidic, fruitlike flavouring in food products"

Yep, I'll guarantee it's in food, drink, toothpaste, chrome polish and lots of other products you've used over the years Per.

[BenelliSEI]

Tasty too?
"It serves as an acidic, fruitlike flavouring in food products"

Yep, I'll guarantee it's in food, drink, toothpaste, chrome polish and lots of other products you've used over the years Per.

Found a jug at my local farm supply! Reading the instruction, when diluted, and it’s lost it’s potency, safe to spread on the lawn! There are some serious safety instructions, but looks good. Thanks Terry!

[BenelliSEI]

The fact that it survived is remarkable. . If the rims are completely  rusty or unsafe.. then they got to be replaced..
 But to find one with all original parts is rare and noteworthy.   Even if you replace with other good original parts.
 In the 1930  and earlier range .. original  survivor bikes are usually worth more than well restored one's ..
 And guess what.. it did not take cubic money  to make it that valuable... more patiences, time and searching.
 You are doing fine you already found the carbs.. major hurdle cleared there.

 I have a question though.. I have I believe a rolled rim , it has a bit if damage .. I think it can be fixed.. but I am not sure it's 750. I suspect it  might be off an early 450 ? Anyone know if it's same part ? I should dig out my 450 parts books.
 FOUND 450 PART NO...44701-283-000  FOR RIM...did not list size , but said Daido

Frank..... Measured the rim that is from my sandcast today. They should be the same rim. Inside the bead, at the base, it measures 2 1/8" wide. The bead face to face (the outside measurement) is 3 1/8". It's an 18" rim, but the actual ID of the circle (tip of bead, across) is 19 1/8". That should be enough to compare? Let me know if you need anything more? John D.

[BenelliSEI]

Wow, I've just found your thread John, what a find! Before you go spending a squillion bucks on chrome, go to a farm supply store and buy a gallon of Phosphoric acid. Buy a big plastic tub large enough to submerge your rims halfway, fill it with the phosphoric acid and water at any ratio (1:10 is usually about what I use) and dip the rims in the tub.

Leave them in as long as you like, it won't hurt them. They'll come up like new, especially if you give them a rub with some nylon or stainless steel scourers. Same/same for your fender. I've saved hundreds, maybe thousands of bucks using phosphoric acid to remove rust from gas tanks, battery boxes, rims, fenders, etc. Unlike other acids, phosphoric acid is relatively harmless, it's used in chrome polish, toothpaste, and coca cola, among lots of other products.

I buy mine from a farm supply store as it's pure (not watered down, like the stuff they sell at hardware and auto parts stores, under various brands) and is sold to dairy farmers to clean their stainless steel tanks and milking equipment. Give it a bash John, a gallon here is around $40 AUD. Your bike looks great, wouldn't it be nice to own a sandy survivor!

Terry... Do you use the same 10:1 ratio for in the tank cleaning???

[Terry in Australia]

Yes mate, I replied in detail yo your question on my K0 thread.

[BenelliSEI]

Yes mate, I replied in detail yo your question on my K0 thread.

Got it all. Thanks!

[BenelliSEI]

Started tearing apart a set of early K0 (4 cable) carbs I want to use here, initially. This set is mysteriously missing the main needle, clip and float valve. Does anyone have any bits or suggestions where to order “good” parts? Thanks!

[Alan F.]

The floats appear to be a more common item.

https://www.partzilla.com/product/honda/16013-300-004?ref=35253e052855c45cf67e8519b81814b4e4fe9d0c

[BenelliSEI]

Looks like 1969-71 are all the same. Will report.

[BenelliSEI]

Busy on this project, the last few days. No pictures, will take some next time.....

Carbs..... Rebuilding a set of early 4-1 cable carbs, as the s/c was missing the originals. Very early bike, it probably came with the "28" carbs, but I want to ride this one, so fine with the next version. The carbs I traded for were missing some parts, so I ordered a very nice set of kits, "Made in Japan". Totally complete, high quality bits, by Tour Max High Performance. I know the general concensus is to stay with "original brass" but in the absence of bits..... Carbs have been scrupulously cleaned, then spent lots of time in my ultrasonic tank. Really coming along

Questions for the Experts: The carbs were fitted with #125 main, but I used #120 as specified for the early cb750's. the needles in all four carbs were clipped in the SECOND slot, down from the top. I can't find any reference as to what the "stock" position is. Anyone know more??

[BenelliSEI]

Progress on the ENGINE.

As stated earlier, the engine was missing carbs, and the starter motor was removed. Not sure why, I thought I'd go over a few things before pulling it from the frame. The speedo indicates just over 17,500 miles, so I checked the speedo drive gearbox and it's working fine. Speedo cable is totally intact. Spun it up with a cordless drill and the speedo works fine, recording mileage. Safe to suggest the mileage is correct.

Oil tank is full, top end is oily, so I plugged in the starter, added a temporary solenoid and a few cables. Pulled the plugs, oiled the cylinders, and cranked it over, by hand, over a few days. No noises, found all 5 gears easily...... Screwed in an oil pressure gauge today, pulled the plugs, and hit the button. Spins freely and within 10-20 seconds, 65-70 psi oil pressure and oil moving around both ends of the cam box (all the inspection caps were removed).

The engine is stained, so head gasket needs to be replaced, but right now I'm only planning top end work! Next will be valve clearances, points and static timing, and when the carbs are done, I think I'll fire it up and see how it runs!

[34barab]

Carbs have been scrupulously cleaned, then spent lots of time in my ultrasonic tank.

Any discoloration with the 5 to 1 water to Simple Green solution?  What temp and for how long?

[BenelliSEI]

Yes..... one part SG: 5 parts distilled water. 40c for 40 minutes. I rollthe carb body around and flip the bowl a few times. Small bits go in a screen container that I bought in the “kitchen center” of a hardware store. I think it’s for hanging bundles of herbs in soup pot!

[Terry in Australia]

Sounds good John, My "rebuilt by an expert" carbs have (standard) 120 mains fitted, and due to the missing top seals, it was running lean, so I raised the needles a notch (they should be in the third, or 'middle' slot) and installed a tired old OEM air filter. 125's are too much for a stock engine, especially with the OEM pipes.

Once you pointed out that I needed the top seals, it's been running rich, so after my ride today I pulled the horrible old clogged OEM filter and replaced it with a K&N filter, which will breathe a lot easier. I may need to drop the needles back to the original position as well, but one step at a time.

K0 Thursday 25 Feb 2021 9c by Terry Prendergast, on Flickr 

[BenelliSEI]

Got it. Thanks Terry and Don. #120 and third slot (from the top) for needle clip.

[MauiK3]

I think you can get OEM stuff from Yamiya but their shipping is pretty slow since COVID.
Of course there is David Silver too.

[seanbarney41]

I think you can get OEM stuff from Yamiya but their shipping is pretty slow since COVID.
Of course there is David Silver too.

Not sure why you keep posting this.  I just ordered from Yamiya and got it faster than 1 week. 

[Terry in Australia]

I think you can get OEM stuff from Yamiya but their shipping is pretty slow since COVID.
Of course there is David Silver too.

G'Day mate, Yamiya were slow a few months ago, but are using UPS now and like Sean said, I'm now receiving my stuff within a week of placing the order.

[BenelliSEI]

I think you can get OEM stuff from Yamiya but their shipping is pretty slow since COVID.
Of course there is David Silver too.

My last order was very quick, usual timelines, no delay.

[MauiK3]

Good to know, thank you for updating me.

[HondaMan]

Started tearing apart a set of early K0 (4 cable) carbs I want to use here, initially. This set is mysteriously missing the main needle, clip and float valve. Does anyone have any bits or suggestions where to order “good” parts? Thanks!

Maybe. Can you send me the tiny number etched around the top of the needle? The real early K0 carbs were changed somewhere around the first of the diecast(ish) K0, and the needles in the carbs changed when they also made the 4th cable a little longer at the factory.