Topic: New 750 owner, various questions.

[DaveInTexas]

Hi folks, I am close to buying a 70 CB750 (and pretty excited about it).
I did not see what I was looking for in the faqs;

1.  This one will likely need carb overhaul, where do you suggest I buy the most complete kit available?
(US)
2.  I thought someone might have written up the entire overhaul and tuning process but could not find such a document, anyone know of one?
3.  What parts on this bike are the more rare or hard to find parts, just as a matter of me wanting to become more familiar with the situation.
4.  How can I tell if this is a sandcast?  Why is sandcast sought after by some?  Does this have anything to do with chain breaks cracking the case or is that another topic? (How can I know if this one has a repaired case, what does that look like?

Many thanks,
Dave

[DaveInTexas]

Ooops.  Maybe the wrong forum?  Maybe too many questions at once?  Don't you hate it when you join a new place and seem to break all their etiquette rules?

Tell me how I should reattempt this, please!

Sorry!

[ProTeal55]

I will give a wack at your questions 

1. Most of these bikes are in need of a carb. rebuild. Lots of places sell the needed parts to
refresh/rehab the carbs. I have yet to do it on my scoot, so I don't know the best place to direct
ya. You might be surprised on what a good Honda dealer might have.
2. As far as a general maint. guide, do yourself a favour and pick up a service manual for your bike. They are the first thing a new owner should do, especially if they plan to do the majority of the work on the bike themselves. Also, start doing some looking around on this board, as the topics that have been discussed in the past might (will ) help you out...
3. Pieces like the tank, fenders, and others are more "desirable" than say the horn, but as you will see, beauty is def. in the eye of the OWNER of these bikes. My bike was complete when I bought it, and I am on a quest to strip it down, and make it as minimal as possible. To each their own..Once again , this site is your new best friend...
4. Do a search on the term "Sandcast" on this forum, and I am sure you will find the info you need..

Welcome to the site, and remember to build the bike the way YOU WANT, as you are the one who has to ride it...

  ProTeal has spoken 

[Dusthawk]

I drop to my knees and bow to the Wisdom of the Mighty Proteal

Peace and Long Rides,

Jeff

[ProTeal55]

I drop to my knees and bow to the Wisdom of the Mighty Proteal

No need to drop to your knees their Dusthawk, I don't swing that way 

[dusterdude]

i dont know,you know what they say bout them bowtie boys.

[ProTeal55]

i dont know,you know what they say bout them bowtie boys.

Come on Duster, you know you can spell your brand two ways...
1. MOPAR
2. SLOPAR

[DaveInTexas]

Thanks PT55, I had planned to buy a manual and hope to find rebuild kits...I guess I will do a search for Honda dealers, there are none for 150miles in all directions from me.  Online sources are better from my location.  Hopefully the manual will explain the carb tuning process well if no one else has written this process up.  Ive seen people make 48" manometers to synch them, 4 vacuum gauges, someone talks of a color stick, just can't find any info on it though.

I saw lots of posts in my search of sandcast but no where did anyone say why it is sought after, preferred.  If they kept cracking open everytime a chain busted, what good are they?!
I did find someone say SN <7415 are sandcast.

Thanks for any responses.

[ProTeal55]

Sandcast + Limited Production Run + Internet = Desirable ( to some people atleast  )

[Bob Wessner]

I saw lots of posts in my search of sandcast but no where did anyone say why it is sought after, preferred.  If they kept cracking open everytime a chain busted, what good are they?!

The sought after part is because of the limited number, less than 8,000 total. The holed cases were an issue with the chain/sprockets rather than the cases themselves. The carbs on the K0 are quite simple and few parts actually wear out, though possible I guess. I would start by giving them and all associated parts a good cleaning before going the rebuild kit route.

[DaveInTexas]

aHA!  I had wondered if it was a real, or perceived value (sandcast).
How can I know if I have an old chain/sprocket that will rip a hole in the case?
I hear of Oring chains.

Still looking for that treatise on carb tuning - yeah if it runs at all I will just clean inspect and reinstall.'
One is reportedly leaking (he turns the petcock off each trip).  Thinks its a leaky float which makes sense.

Also now I hear the clutch plates may have set up (glued themselves together due to sitting in oil for years)... "just take them apart to fix this problem."

[scout18]

What year is your new bike gonna be? I think the sandcast were 69 model year. Does the bike run? Can you work on it?  I have had the carbs on and off so many times in the last year I can do  it in my sleep and I had to repalce the screws fo rthe clamps that seal them to the boots. try greenspun archives too. lots of info. Welcome to the forum  I am pretty new myself.

[DaveInTexas]

Hi its a 1970, why have you taken your carbs off so much?

[Bob Wessner]

why have you taken your carbs off so much?

You'll find out. 

Just kidding, but you may unless you've done this sort of thing before, or are better at it than I am (entirely possible, if not likely). I had mine off and on many times myself after the bike had been stored for 20+ years and everything needed cleaning, etc. Besides, it a rite of passage thing. 

[chung]

Where the chain/guard goes to the left side of the engine you can remove the sprocket cover, clean a lot of muck and see a repair. Most were done with the motor still on the bike (not hard to see) Do a search for The Satanic Mechanic, he used to have a list with #s for when they changed stuff like Sandcast, push/pull throttle cables and such. The made a lot of change to the engine the first few years.

[SteveD CB500F]

"What is a Sandcast?" FAQ 

www.sohc4.us/forums/index.php?topic=2894.msg37985#msg37985

[DaveInTexas]

All good info, thks

Should I remove them all if I just want to change a float, or should I just drop the bowl on that one carb?