Topic: Fantasy carb kit.

[faux fiddy]

This is actually  a marketing survey  question for people with  later model carbs on other bikes.
If you were to have a manifold that adapted a set of '90's or later carbs to a CB 750, what would be the best donor?

Consider performance, compactness and production run (and corresponding economical availability). Would it be from a 1,000, 900, 600?  What bore?

http://vid237.photobucket.com/albums/ff191/salmonshark/ntakecut.mp4

[faux fiddy]

What carbs on your modern bike with a similar output can you modify with pods or pipe that  tune well without them going ape excrement out of whack?

Someone has had success tinkering with them out there.

[strynboen]

i dont like the later vaccum kontroled types..vho ran to the injektions/ ignision kombi comuter kontrolled systems took over..there are no better/easyer kit

[lucky]

The absolute best carbs for the CB750 is the 1969-70 carbs.

Easy to remove float bowls with spring clip. Do it with carbs on the bike.
All jets easily accessible.

Slides all removable with carbs still on the bike.

All jets easily removable with carbs on the bike.

Idle screws all marked for lowest position.

Made the most power.

No throttle shafts. No lifter arms. A lot less weight.

[strynboen]

yes...but the erly types can not hold cyncro for long...all this kabels are a mess..later types vith is in a bank..and have kommon linkage are easyer to vork on..but the latest lean types have also problems...araund1978


i like best the mid age  araund 1976 types of all modells both 750 500 ..

[faux fiddy]

i dont like the later vaccum kontroled types..vho ran to the injektions/ ignision kombi comuter kontrolled systems took over..there are no better/easyer kit

CV carbs seem obsolete and large.

The idea is  that a donor be from a more modern bike, flat slide or otherwise, that is available common and cheap on e-bay. 

[strynboen]

i have  one delorto flat slides on my mz 150..they vork very vell..  but still like a choke vho are locks the air intake..better then them vho opens for more gas like mikuni types..

[Bankerdanny]

You pose an intersting question. Of the many many project bikes I have seen on this site, I can only recall a couple that opted to use different carbs, and they have pretty much all been Mikuni Flat Sides.

Has there been a mass produced twin or 4 cylinder bike that has used those that sold in high volumes? CV's seem to be the most common type of carbs on the pre-fuel injection bikes from the 80's, 90's, and early 2000's.

[PeWe]

Mikuni VM29 Smoothbore, Keihin CR31 both expensive when I have found old ones on eBay.
New Mikuni RS34 does not cost that more, sometimes less. These might need more displacement like 1000cc

Forget the money, just order a set of Mikuni TMR32-D7 and be happy. I want but need new helmet (Schuberth C3 Pro) and boots from Santa. I have been really good.....

[lrutt]

I dislike the CV carbs. They work, but don't have the same snap as a regular carb. Also hate enrichener circuits, give me a good old fashion choke anyday, better yet, a tickler like an Amal

[strynboen]

as kid i used to vork on/vith bing kaburettors..they vas simpel presise and easy to work on..and have real choker and" drovner"tickler..on danisk "tipper"

[Bailgang]

I wouldn't say all CV carbs are slow responding, the Cv's that were on my kids cbr600 F3 were the snappiest carbs I've messed with however they were picky, just the slightest mod to the engine would make them throw fits. His cbr already had an aftermarket exhaust but he installed a different one, the only real difference between the 2 was different scavenging of the header design and that bike ran like crud once the new exhaust was on. He had to get a jet kit and spent about 2 months getting the carbs to cooperate again. By the end of the summer he had it running great but being a glutton for punishment he tore the engine down over the winter, sent the cyl head out to have it ported and found himself back to square one with the carbs again once it was all together with the ported head. He got that sorted out but by that time he was so sick of messing with carbs that he sold the bike and bought a cbr600 F4i.

[faux fiddy]

Has there been a mass produced twin or 4 cylinder bike that has used those that sold in high volumes? CV's seem to be the most common type of carbs on the pre-fuel injection bikes from the 80's, 90's, and early 2000's.

This is the line of thinking, maybe a more modern gsxr.  I think I saw a thread elsewhere with that swap, and I will look for everything else with this project in mind.   The idea is to have one type in mind, and design a manifold or other way of mounting more modern carbs.

I have piston type CV carbs on bikes, it seems like they chatter when they should open smooth and evenly.

Programming and CNC work, and then  a prototype is the idea. Gotta find something to di with these machines.

[faux fiddy]

Here's the general idea and they pulled it off pretty well. Early nineties carb sticking with a Honda brand.


It looks easier to get to than pulling off a breadbox.  The idea is to design this set of carbs a set of mainfolds  to bolt to the sohc.  I think the programming to do these shapes on the hitachi came with it and  is still around here.

http://www.cb750.com/threads/837-1991-carbs-on-a-1980-engine

[jamracing]

It's hard to adapt newer carbs to older bikes, as they are all larger diameter bores, so you'll suffer at lower RPM. I would think the closest would be the newer Nighthawks, Suzuki Katana 600's, or maybe even the early GSXR 1100's...

[trueblue]

GS650 carbs will fit onto the early 650 heads, you need to use the boots off the later 650's to make it work though.  I haven't gone through the tuning process yet, so I don't know what's involved there yet. 

[gerhed]

I have dual Mikuni VM34 carbs and Cyclex manifold on my 750F-works great!
Does this help the discussion or did I miss the point.?

[faux fiddy]

I have dual Mikuni VM34 carbs and Cyclex manifold on my 750F-works great!
Does this help the discussion or did I miss the point.?

Definitely looking for what works, so yeah.

[Bankerdanny]

Are the VM's a stock carb on a production bike? I think what Faux Fiddy was thinking was an adapter that would allow the use of a more modern carb that would be easily and relatively cheaply available via eBay or wrecking yards.

[MiGhost]

Are the VM's a stock carb on a production bike? I think what Faux Fiddy was thinking was an adapter that would allow the use of a more modern carb that would be easily and relatively cheaply available via eBay or wrecking yards.

VM26/28's were used on kawi 650-1000, not sure on the 29's