Carbs and Other Queries. Longest list of questions on earth!

Considering scrapping my expert throttle bodies and going to carbs. It just seems an easier way to chase down some bhps's for NA tuning.

Anyway, been reading builds (suggested by the all masterful frank, thanks as always, and thanks to the individual authors of these blogs also)...
Machi San's - Dattosan Machi aka Project Nipper
BiAS's - My GSX

So here's where i'm at with thinking this out, and what i need help with incidentally lol...
  • CBR600 carbs seem to be everyone's favourite? I believe there are different series' of these, which are you using? I don't see any specifics, but a search on ebay for "CBR600 Carbs" i see a variety of different sets.
  • I see people are using them in stock condition too, without rejetting them or anything. Anyone done the jetting and seen immense gains? I'll maybe look at this at a later stage.
  • I've seen a few mentions of a Fuel Pumps, FPR's, Carb Regulators...red top fuel pump, a lot of stuff i know nothing about! I'm guessing my standard fuel pump is no good, or what is the simplest most effective way of me solving this issue?
  • Lastly - How do you solve a problem like distributor? I've read the above blogs but i only see reference to Machi San using an adaptor made by Superls, and BiAS has a homemade one but i only see it in the engine in situ. I'm guessing this pic sort of shows what i need to do?
Weld the end of the CG10 Distributor onto the MA10 shaft (black bit at the end)? Is that a precise length, or should i just get it roughly right? Lol.​
What about wiring? Will this work with the K11 ECU?​

DSC00055.jpg



Couple of randoms ones...

  • Has anyone done carbs in the K11, is space an issue? Looks to be a lot more room in the K10.
  • Anyone ever done big end bearings on a CG10DE? Anyone found a set? I was maybe going to chat to Matt Humphries. Just i sold the white Micra on because it needed a new engine. Hopefully my mate will show up here with it rocking and rolling again, but it would be a good test bed for him and I if we had it running again.
  • Lastly, below pic...what kind of welding is this? Looks very MIG-like on our manifold but i though it was Aluminium. Hmmm. Optical illusion?!

mani4.jpg
 
Manifold was made from steel, cheaper to work with while i was figuring out where everything was going to go, have a copy being done atm in aluminium. cbr600 carbs will work fine, they WILL have to have the jets drilled out in order for it to run anyway right. I would start at 1.5mm and work from there. As for the pump, use the pump from the bike the carbs came from, most hondas run a small electric pump. Failing that, a facet red top pump and a fpr set at 4 psi (get a gauge to measure this properly) will get you in the right range. Ignition is more tricky, modified k10 will work just fine, i have used one myself with no issues. For even better spark control then the megajolt jr would be your best bet. Google it and see for your self, its mappable and would be far more effective in the long term
 
OP
OP
Revmau5
Nice advice mate. I'm going to also make my out of mild steel also, can't weld alu atm! Lol. Reason i ask is because it looks so damn similar to our manifold, usually people just fire something together, hats off sir!

I'm looking at adjustable fuel pressure regulators too. I've ebayed Facet Fuel Pumps. Again something i know little about. I see ones on there which do various PSi ranges. There are ones which do up to 4psi and then i see the redtop one, about twice the price. Hopefully someone can validate that lol, but i'm also wondering what it is about the redtop that a smaller pump wouldn't do? Not being stingey, just curious!!
 
Just a point for fitting them in Rev if you still wish to run a brake servo you will need to canter the tubing to the nearside in order to clear it. :)

DSCN0167.jpg

DSCN0089.jpg
 
OP
OP
Revmau5
Yeah mate, good advice that...i've had that problem with my throttle bodies already! :( There's also a power steering thing in the way of mine in think. Had my TB's in my white micra and i moved them to my red micra i was like WTF!?!?!?

All sorted though. That's another immensely neat manifold sir. What way did you counter the notch for the fuel rail into the head when using circular pipe? Also incredibly tidy bends. Guessing this wasnt done in a run-of-the-mill workshop? Lol.

Question for anyone else: Anyone got any RR BHP figures for the carb conversion (particularly with the K10 dizzy lol)? Funny, on my way to work i stopped at the guys in Autotune next to me to ask them about any experience with carb conversions and the owner showed me some pics of his carb'd up Micra from back in the day. Co-incidence!
 
OP
OP
Revmau5
Last but not least...i was on Gumtree there and i see a cheap set of Yamaha FZR600 carbs. Anyone any experience or know if these are suitable/unsuitable?

Guessing it makes as little or no difference, really only a question of diameter since the jets will need work anyway surely? Won't be much difference in a 600 or even a 750cc bike counterpart i'd imagine.
 
All sorted though. That's another immensely neat manifold sir. What way did you counter the notch for the fuel rail into the head when using circular pipe? Also incredibly tidy bends. Guessing this wasnt done in a run-of-the-mill workshop? Lol.

I carnt take the praise for the mani bud it was made by Bogg brothers i just gave them the angle/measurement to clear the servo lol They did a real neat job they matched up the alloy with the inlet ports exactly so it fits the head perfect: (sorry for the big pics)

DSCN0162.jpg
 
OP
OP
Revmau5
Just another curiosity, i see you have a vacuum take off for the brake servo on only one cylinder. Does this matter? On my throttle bodies i have a take off at each for the fuel rail vacuums. Always wondered does one make a difference to the four. Hmmm! Thoughts!?
 
Just another curiosity, i see you have a vacuum take off for the brake servo on only one cylinder. Does this matter? On my throttle bodies i have a take off at each for the fuel rail vacuums. Always wondered does one make a difference to the four. Hmmm! Thoughts!?

I did ponder it at first to be honest but i carnt see it making much difference, i've not see any change on spark plug color or anything.. most Golf manifolds i've seen have a single takeoff & i've never heard of it causing different running issues across the cylinders :)


Did you get the ITB's up and running on the standard ECU?
 
OP
OP
Revmau5
Fair point.

Yeah i did mate, ashamed of the drain pipe ive used for a plenum...no pics yet. I've documented the build again though from scratch so you'll have to trust me for a week or so until i upload it.

Just started make a MDF mould for a vacuum form a nice one. I promise i'll do some pics and stuff then before i start the carbs. It's running pretty OK, i mean ive been driving to work and back 50 miles a day with the car since they went in during November.
 

superls

K10 Tuner
i had bike carbs on mine, cbr600 from around 96-98 ish,

as for distributer, i machined an adapter to fit a k10 dizzy in a k11 engine and modified a k10 dizzy to fit
 
Top