Topic: Single or Dual carb on 750

[kevins750]

Forgive me if this is on here somewhere already...
Has anyone ever seen a single carb set-up on a 750? If so, have a pic?
Or if I was to use 2 flat slide Mikuni's, what size would be suitable....836 75F motor would be my choice for this application...What is the advantage of using custom cast aluminum intakes over tubing or stainless tubing...?

[bucky katt]

the cycle exchange sells a carb kit including 2 34mm mikunis on manifolds of their design.

[MRieck]

4 carbs are the best.

[kevins750]

4 carbs are the best.

That was the answer I expected from one of the experts....Although I do like the look of the dual Weber's, I will be using 4 carbs...

[Ecosse]

does anyone know if the cyclex set up fits the stock framed bikes? i've only seen them one their wild choppers.

fwiw: the benelli sei (six) had two 3 bbl carbs. for anything less than a race engine, and providing properly designed manifolds, how lousy would less than four carbs be?

[bucky katt]

does anyone know if the cyclex set up fits the stock framed bikes? i've only seen them one their wild choppers.

fwiw: the benelli sei (six) had two 3 bbl carbs. for anything less than a race engine, and providing properly designed manifolds, how lousy would less than four carbs be?

not according to ken, though i think it was gerhed that did fit those carbs in a stock framed 750ss. as i understand it, theres really not enough room between the carb air horn and the frame rail to fit a filter without some mods. he actually talked me out of buying one of his carb kits a few years ago for that reason.

[mlinder]

I had issues with the cyclex setup on a stock frame. Went back to 4. Not to say that the cyclex setup wasn't high quality, and Ken did caution me that fitment would be difficult on a stock frame.

[754]

Kevin, I have been running Dual Webers for a long time, I really like them, but aircleaners are hard to fit in stock frame. I had ones that fit well (bugeye type) but the foam started crumbling, so I ran without.

 I could make a better aircleaner I prefer K & N, but did not get to it.

 2 types of manifolds, splayed and straight, I have splayed but on the straight you could make a 1 pce cleaner, a bit easier. I also have a straight manifold but have not run it yet.

 As I run kick only and small battery, I did consider dropping battery lower and making a plenum leading to a canister type filter under the seat, like 900 Kawi.

 If you can get a manifold(or complete setup) I would look for carbs & try it. They have very light throttle pull, easiest carb to change jets, get super mileage, and they look freaking cool

 I just got a complete set for my buddies bike, and another  guy here in town has a manifold and carbs (need jetting, get at it LB).. cant wait till the three of us are riding together on hot rod  750s, with Webers..

They may not be everybodys cup of tea, but I sure like em.

[kevins750]

I really like the look of the Weber's and have a connection to make manifolds...The area between the carbs and the rear tire has been "cleaned out" ..bike will be kick only with the battery being relocated under the rear seat hump as with all electric's...

(((((754...Do you have a close up of your dual set-up? )))))))

[754]

Kevin check your PM..

[fishhead]

Heres an RC ENG. Weber DCOE 40  set up.
   The 1st pic is how it cam from RC E. Twin throttle cables and the PO probably had them Chromed.

 My set had the bosses on the ends for the cables cut off, so I made a single throttle shaft to connect the 2 carbs to a single cable set up.

 These Webers are the best carbs I have had on my 750 to date. My velocity stacks are close the the frame rails and usually have UNI foam wrapped around them for filters. I think 754's manifold has the carbs splayed and have more room for filters than my set does.

[j-conn]

wow...
very cool!!!

[JLeather]

I'm gonna be running a set of Mikuni Solex's on my next engine, which are just like the webers only a bit smaller overall.  Aftermarket frame, so plenty of room for the filters   Sorry, no pics on my computer at the moment, but I think they're definitely the baddest looking carbs for a CB750

[754]

I got the set for my buddys bike last week, they will look good..

 I should try to jet a set of Dellortos seeing as I have 4 carbs on the shelf and an extra straight manifold.. plus the complete Weber set for my motor..

.. noboby that rode fours ever rode my bike, without remarking about how much better the throttle response was with the Webers..

[MCRider]

4 carbs are the best.

That was the answer I expected from one of the experts....Although I do like the look of the dual Weber's, I will be using 4 carbs...

Dual webers are essentially 4 carbs as each is a 2 bbl carb.

i had a set on my 750cc road racer and they were great. I think i ran 32mm venturis. All the jets were replaceable from a wing nut cover on top of the carbs. My manifold skewed them out at an angle that hit my legs. This allowed for a single throttle cable in the center, rather than a split cable going to the outsode of each.

But they hit my legs , I think I would have preferred the straight manifold.

[JLeather]

Just for fun, here's an oddball setup:



It looks to be a knockoff of a POSA setup done by "DO IT ENG".  As a shameless self-plug this setup is on eBay right now to fund a set of custom J&E pistons I need.

[luhojs]

What's the link to the auction?

[ColinMc]

Grr, don't tell anyone i want to bid on those! Found that setup the other day on ebay and have been watching it lol.

[MJL]

Heres an RC ENG. Weber DCOE 40  set up.
   The 1st pic is how it cam from RC E. Twin throttle cables and the PO probably had them Chromed.

 My set had the bosses on the ends for the cables cut off, so I made a single throttle shaft to connect the 2 carbs to a single cable set up.

 These Webers are the best carbs I have had on my 750 to date. My velocity stacks are close the the frame rails and usually have UNI foam wrapped around them for filters. I think 754's manifold has the carbs splayed and have more room for filters than my set does.

Aside from looking so bad ass, what's so fab about it?

[bucky katt]

Just for fun, here's an oddball setup:



It looks to be a knockoff of a POSA setup done by "DO IT ENG".  As a shameless self-plug this setup is on eBay right now to fund a set of custom J&E pistons I need.

those look like the 32mm mikunis on my suzuki titan.

[MCRider]

Heres an RC ENG. Weber DCOE 40  set up.
   The 1st pic is how it cam from RC E. Twin throttle cables and the PO probably had them Chromed.

 My set had the bosses on the ends for the cables cut off, so I made a single throttle shaft to connect the 2 carbs to a single cable set up.

 These Webers are the best carbs I have had on my 750 to date. My velocity stacks are close the the frame rails and usually have UNI foam wrapped around them for filters. I think 754's manifold has the carbs splayed and have more room for filters than my set does.

Aside from looking so bad ass, what's so fab about it?

Its hard to explain how much better the engine can run with decent carbs and the Webers were top of the line. Starts better, idles better, throttle response was amazing, top horsepower noticeably higher, just hard to expalin if you've never changed out carbs.

In the same era I bot a replacement single throat Weber for my Opel Kadett. Same thijng, better response thru the range quicker start up and warm up, better gas mileage and power. And it weas a straight bolt on, needed no further tuning. Amazing.

I've run Mikuni smoothbores 29mm on my 750 since then. They are amazing as well, but the edge goes to the Webers. With my flared out manifold the riding was too compromised for me and there are no compromises with the 29s.  Had I known there was a Weber manifold that held them straight out from the engine, I'd likely still have them.

[754]

Are you talking knees clenched tight against frame during spirited riding/racing.. sorta thing../
 They stick out a bit, had to notch my stock sidecovers for bugeye filters, never seemed to bother my leg/knee much.. I will find outwhen I put this latest set on.. maybe my thin seat put knees further ahead?

...........................................................................

 Webers have a wider range of jetting than can be adjusted.
 Emulsion tubes, air corections, mains, slow jets, venturi size, even accelerator pump size, they are all adjustable, and for the most part very quickly..most of them with carbs in place.

 The response, it can be very nice.  These carbs in various forms have been used on many engines, and have been described as the "closest thing to fuel injection.. Even Holley carbs can be run with adaptors to use Weber jets.

 Also they have ball bearings on the throttle shafts, resulting in very light throttle pull, you can easily work the throttle with thumb and forefinger..

 I notice that there are at least 2 folks on here that roadraced with them, changed to Mikuni smoothbores, and wish they had not.. to me that says  more than someone that never ran them saying something else is better..

 So you have to draw your own conclusions, but I aint switchin..

[Pinhead]

Do the Webers require custom manifolds or do they coincidentally line up with the stock intakes?

[fishhead]

Do the Webers require custom manifolds or do they coincidentally line up with the stock intakes?

 Both sets I have had come with special flanges to fit the 750 SOHC head.

 On My 750K, I have had the stock carbs, 750 PD carbs,28mm Mikunis and the Weber DCOE 40's. The Webers are the best by far, awesome throttle response, idles so much better and they just basically perform better than other carbs I have had on my bike.

 Its kinda of like having a Quadra-junk on a SBC and then changing it out to a double pumper Holley. The Quadra worked fine and ran great, but once the better carb was put on the difference was very noticable.

 The Webers are a bit bigger and bulkier than the stock carbs though. The are also heavier than the stock set up.

[ColinMc]

Where can one source a set of these? I'm looking for other carb options for my CB750 project since my stock ones are beyond repair.

[gerhed]

does anyone know if the cyclex set up fits the stock framed bikes? i've only seen them one their wild choppers.

fwiw: the benelli sei (six) had two 3 bbl carbs. for anything less than a race engine, and providing properly designed manifolds, how lousy would less than four carbs be?

not according to ken, though i think it was gerhed that did fit those carbs in a stock framed 750ss. as i understand it, theres really not enough room between the carb air horn and the frame rail to fit a filter without some mods. he actually talked me out of buying one of his carb kits a few years ago for that reason.

Yes, I did fit the Cycle-X carbs on my 750F
Tight fit--no room for much of an air cleaner.
Runs well, though