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79' cb750 build in cold Sudbury

Nust08

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Hi Everyone,

So this past summer I picked up a mostly complete 79 cb750 to build over the winter. This weekend I got to wheeling the bike into the shop and starting on it. So the plan is to build a pretty simple brat style bike with an emphasis on minimalism and reliability. So the plan will be a rebuild of the key engine internals, a complete rewire of the bike including a motogadget blue unit to use my phone for a key, LED headlight and blinkers, clip ons and motogadget controls, simple throttle setup and I've got a k6 gsxr radial master floating around i'll toss on for the front brake. I'll be leaving the rear drum just because I happen to like the look and go from there. forks will get new springs and same for the rear. Nothing overly exciting. I will be doing some cutting to that tail section to flatten out the infamous DOHC frame.

Anyways heres a few shots of what it looked like when it rolled in and now that I've cut most of the tabs off and swapped the rear wheel for the 17" spoked wheel.

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Be strongly advised the OEM CV type carbs loathe pod type individual filters, the stock airbox rules on these engines. A very common mistake most make.
 
Thanks, I've seen the plethora of posts on the forum about that issue so I'm definitely aware. The pod look is the one I prefer so i'll be looking at what I can do to solve it. the bike came with at least 3 full sets of carbs in a box of goodies and I haven't taken the time to look to see if they are all the same. I've seen some performance carbs for sale online but a thousand dollars for some new carbs seems a little steep. Anything you can suggest that's in the middle amc?
 
So AMC your post had me revisiting that carb issue that I was aware of but hadn't dug into in huge detail. I've read a bunch of your responses to other peoples questions and issues on the subject so this now brings me to some questions to clarify my understanding.

1. Your position seems to be that pods CAN be used on the DOHC units, ASSUMING that the engine compression checks out between 150-170psi and proper tuning is done. This will still result in a slight loss of torque at the bottom that's provided by the airbox and potentially a loss of 500rpm at WOT. Is that correct?

2. Keeping the airbox is the easiest way to retain all the power/torque (I still have mine) but god its ugly.

3. Assuming someone rebuilds the motor and has the bike tuned right what sort of reliability can one expect from the pod setup?

4. Since the pod issue is as you explained a result of the CV control of the slides and requires a shared vacuum to alleviate variances in the firing order could a sort of pre carb "slim" airbox be built? For example a narrow chamber similar to the rectangular style joined filters sometimes seen on bikes that's not open on its sides and instead then mounts pods to its face? Clearly this would have less total volume then the stock filter but could it help reduce the CV issue somewhat? Then still maintain some semblance of style?

5. Asides from the Keihn CR and the Mikuni FCR (that may not be correct) is there any other viable non cv type carb that can be used that is
A. Reasonably affordable and
B. Worth the time to modify to work?

6. Can you please expand upon the 2 carb setups I've seen around the web? what are the pros and cons?

Clearly your well versed in all things carbureted and I am a person who despises them with great passion as they seem to be a pain in my ass. I've always been told by my father in law (shop owner for 30 year) that anything with carbs can be reliable if you set it up right the first time, which brings me here. This bike is being built for both aesthetic appeal and reliability. Neither one nor the other taking absolute precedent over the other. My specialty has never been carbs and I do like to learn from the wisdom of others. that being said my ideal look is pod filters or something of the like and that leaves me in a bit of a jam with how to move forward.

any advice on the subject is greatly appreciated.
 
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