CB750 Chopper project (this will take a very long time!)

[xriccix]

So here we have what will be my first bike build project and I warn you know I will be learning along the way! It's also worth saying that my wife and I are in the middle of moving to be closer to family, this will take a while!






That's the bike as it currently sits, I also have 3 boxes of bits which have everything else in.

Things I'd like to do to the bike:
Engine refurb
Paint engine in VHT wrinkle paint
Powder coat frame
King and queen Seat
Bigger sissy bar
Forward controls
Coffin/Peanut tank
Dual Carbs
4 single slashed exhausts
Springer or Girder front end

Any help or advice about the above list would be greatly appreciated!

[PRWIS13]

Well, any updates? Its been a month. How did it run when you got it? How much did ya need to put down for it?

[jess]

Just my opinion but the girder fork is my preference. It has more potential for adjustment, the wheel mount is solid and the fork assembly is heavy enough not to become gooey. I don't have much experience with either, just from an engineering perspective, the girder seems the better mechanism.

Why go from four carbs to duels? A word of caution, you have to know your intake config before you recarb. If one cylinder opens before its manifold partner closes you'll suck in mix from that other cylinder (that I do have experience with). Those CB750s have more horsepower per cc than any other bike. Honda engineered them to the max. The way I see it, why mess with perfection? I'll recommend to leave the engine stock.

When you pick your tank, remember its volume effects range.

[xriccix]

Well, any updates? Its been a month. How did it run when you got it? How much did ya need to put down for it?

Still in the process of moving so nothing much has happened, I've slowly been collecting parts and will continue to do so. If only I lived in the states where there are so many at decent prices! Shipping is a killer!

Just my opinion but the girder fork is my preference. It has more potential for adjustment, the wheel mount is solid and the fork assembly is heavy enough not to become gooey. I don't have much experience with either, just from an engineering perspective, the girder seems the better mechanism.

Why go from four carbs to duels? A word of caution, you have to know your intake config before you recarb. If one cylinder opens before its manifold partner closes you'll suck in mix from that other cylinder (that I do have experience with). Those CB750s have more horsepower per cc than any other bike. Honda engineered them to the max. The way I see it, why mess with perfection? I'll recommend to leave the engine stock.

When you pick your tank, remember its volume effects range.

Still looking into girders, tempted to leave the front end as is for now then see how it goes. Dual carbs was simply for the looks. http://www.cyclexchange.net/Honda%20...arb%20Page.htm for reference!

Not planning to do much to the engine itself apart from check its solid and give it a good clean and repaint.

Im currently looking for a coffin tank I like!

[Nimrod]

First thing you should do is get a manual. these are easy to work on, follow it and you will be ok. Next, get an impact screwdriver, you will need it to break those crappy soft headed screws loose. And you will need an inch pound torque wrench.

Forget the dual carbs. Yeah, they look cool, but trust me on this, you lose a lot of power with them. And, if they aren't lined up exactly perfectly correctly (which is almost impossible to do) one cylinder runs lean and one runs rich. If you have a set of stock Honda carbs for a CB 750, those work perfectly fine. Not saying never do them if you want, but that is a tough way to start off. Personally, I would put that money towards a Dyna electronic ignition and eliminate the points.

Lastly, if you need anything CB, contact Kate. she will get if for you at the best price. http://www.cycleonemanufacturing.com/

Other than that, its all fun.

[xriccix]

First thing you should do is get a manual. these are easy to work on, follow it and you will be ok. Next, get an impact screwdriver, you will need it to break those crappy soft headed screws loose. And you will need an inch pound torque wrench.

Forget the dual carbs. Yeah, they look cool, but trust me on this, you lose a lot of power with them. And, if they aren't lined up exactly perfectly correctly (which is almost impossible to do) one cylinder runs lean and one runs rich. If you have a set of stock Honda carbs for a CB 750, those work perfectly fine. Not saying never do them if you want, but that is a tough way to start off. Personally, I would put that money towards a Dyna electronic ignition and eliminate the points.

Lastly, if you need anything CB, contact Kate. she will get if for you at the best price. http://www.cycleonemanufacturing.com/

Other than that, its all fun.

Thanks for the advice, I've sacked off the dual carbs for now. I have a manual, hard copy and PDF. I also already have all those tools! I have seen the cycleonemanufacturing.com website before and heard good things about them from over at hondachoppers.com. Shipping and importing can be hella expensive when trying to get stuff from the states, so i'm trying to source a lot of stuff this side of the pond.

Saying that I've manged to sort a a few bits from the states that are currently being shipped over, I'll update with pics when they arrive!

[xriccix]

As I cant work on the bike right now I thought i'd post some pics on parts that I have bought for it

Springer arrived and I'm super happy with it, needs some work but for the price I paid it was an absolute steal.



Got 4 of these bad boys as well!

[Tattooo]

Very nice start............

[xriccix]

Small update from me, Garage is now finally ready for the CB750 frame and engine coming out of storage this weekend. Bench was built by my brother in-law and myself, only cost around £50 has he had lots of free wood . Still not the biggest space but should be fine for what I need.*



First job I want to get sorted is the carbs. This is the set that came with the bike, from what I can see right off the bat there are a few missing bits, a couple of nuts, throttle return spring and the bottom connector for the throttle return spring, I cannot seem to find a name for the damn thing or where to buy one??



Apart from being filthy the carbs look good, took the bottoms off and looks clean inside, I'm still debating a full rebuild. I guess it will come down to if i used a bread box or velocity stacks and therefore might need to use different jets.*
The options I like are both from*http://www.steeldragonperformance.com and sexy as hell.*




I'll update again after the frame is on the bench.*

[TriNortchopz]

Great chopper project! For stock engine parts in UK, this guy seems to have every part, even them little bits: David Silver Spares Ltd
I didn't see what year your engine is, so just plugged in 1976 here:

https://www.davidsilverspares.co.uk/CB750K6-FOUR-1976/

This place lists parts with schematics for reference; I chose CB750K for England:

https://www.cmsnl.com/honda-cb750k0-four-england_model14347/partslist/#.XH3-xbiaXF8

see example of carbs below:

[xriccix]

Great chopper project! For stock engine parts in UK, this guy seems to have every part, even them little bits: David Silver Spares Ltd
I didn't see what year your engine is, so just plugged in 1976 here:

https://www.davidsilverspares.co.uk/CB750K6-FOUR-1976/

This place lists parts with schematics for reference; I chose CB750K for England:

https://www.cmsnl.com/honda-cb750k0-four-england_model14347/partslist/#.XH3-xbiaXF8

see example of carbs below:
[ATTACH=CONFIG]91662[/ATTACH]

David silver is great for parts, I found out the part and part number - Plate spring setting 16066-300-004 - these seem to be hard to come by, as David Silver no longer do them, found them in Germnay for a silly price, might just have to suck it up

[xriccix]

*Update*

Started pulling apart the engine, I noticed the case was damaged as I pulled of the starter cover. Hopefully this isn't to hard to fix?!

I also seem to have lost my shop manual, god knows where it could be! As soon as I get another copy sorted I shall be stripping down further.

[dowood1]

Nice looking bike / project , like the springers and the headlamp to , should look good on it

[TriNortchopz]

I am wondering if you had the engine running before you started teardown - got any history on it? What is your idea with your "engine refurb"? Did you do a compression test - that can be helpful diagnostic info as you prepare for the rebuild.

That is a nice rigid frame - looks like an C&G:



This is a 'Lowriders by Summers'
check out their parts section: http://www.lowridersbysummers.com/parts/index.htm

Good lookin' springer.

For that broken section by the starter; was there a tab on it If not, you could just fill it with aluminum putty, as it is not structural; something like this:

[xriccix]

I am wondering if you had the engine running before you started teardown - got any history on it? What is your idea with your "engine refurb"? Did you do a compression test - that can be helpful diagnostic info as you prepare for the rebuild.

That is a nice rigid frame - looks like an C&G:
[ATTACH=CONFIG]96410[/ATTACH]

[ATTACH=CONFIG]96402[/ATTACH]
This is a 'Lowriders by Summers'
check out their parts section: http://www.lowridersbysummers.com/parts/index.htm

Good lookin' springer.

For that broken section by the starter; was there a tab on it If not, you could just fill it with aluminum putty, as it is not structural; something like this:
[ATTACH=CONFIG]96403[/ATTACH]

The engine had been sitting for 15+ years, compression was good, but I want to do a full rebuild. I'm treating this a learning exercise and enjoying it very much and I really want to say I built this bike.

In regards to the frame my research has said the same