MODIFICATION , STOCK 2BBL KEIHIN CARBURETOR

[Civvy]

So the white discs are to be blocked? what do the red arrows coming from them mean? are the vent tubes the ones sticking out in the chokes of the carb (one of them being outlined by the red lines you made)?

Cheers

[A20A1]

no white discks are not blocked, they are the spaces corresponding to the emulsion tubes on the carb below.... the red arrows show where that area should vent the air correction jets to... so the secodnary air correction vents into the float bowl and the the secodary barrel... the primary only vents into the float bowl.
You only need enough room so that when you put the top hat back on you don't cap the top of the air correction jet... it needs breathing room.
You just blocked off the air correction jet for the primary barrel... that is bad becasue you have no other air correction to feed from since you removed A,B,C You need to hook letter C ((the letter next to #14)) to something to get air correction back or you need to start swapping jets to weber ones... or you can just remove the putty you put on.
I'm sorry I didn't put up a warning... I'm still in the process of modifiying/testing that carb. I've been waiting to get a stock manifold so I can use it.

OMG... you cut off all the vacuum brass ports on the top hat to the ABC didn't you? and also the one for #14 powervalve??? !!! ??? you'll be sucking up so much more gas at low throttle and idle it will give bad milage and poor performance.
I have a spare top hat... not in the best of condition tho...
I was going to give you this pic to use so you can trade C air correction for the one that B has...
I was going to say connect B to C and then make a new top hat gasket but do not cut a hole in the gasket where the arrow is pointing...
this should seal the passage and let the air correction in the primary barrel use the B air correction jet. You plugged the C air correction already... the one shown in your pic with the white arrow.

The new gasket should block the port in the pic above as well as block the accel pump bleed channel, if you want to do that...
using the gasket to block ports is better since it can be undone. but in some places putty is needed.

yeah but air correction is needed becasue it fills in the fuel gaps between Idle and WOT, or part throttle to WOT...
Without air correction as venturi vacuum increases so does the fuel... and there is no braking effect... so at some point you'll be way rich.
It's worth it if you like to have the stall then go effect.
oh the vent tubes are the large brass tube sticking out of the top of the top hat and sort of hang over into the barrels... the better they breath the better your carb will run... thats why I tired to find a way to hook the vent to venturi vacuum... the one that the vacuum secondary uses... or there are a few other ports but they have less vacuum...
If you can somehow add a tube to the float bowl, high so it doesn't suck up gas... your float should fill up faster. Don't ask me why but it seems to help.

Pluging the accelerator bleed channel should give you a better fuel suirt when pressing the gas...
the other hole I marked sits above the idle passage and is the air correction for idle... if you plug that with a new gasket then you should get more gas durring idle and slightly off idle maybe to 3,200 rpm...
but hopefully not uncontrollable amounts of fuel... you may have to adjust the air fuel ratio screw after plugging that hole.
Cutting a new gasket is a pain... don't be afraid to leave a lot of meat on the fuel bowl side... its only the barrel and jets passages you have to be careful when cutting out.

That mod in my opinion is not worth it... if you want switch to the A18 head and buy the manifold that converts it to dual weber carbs then do that... the Stock A18 head and carbs will flow less then the accord head and carbs... only good thing is you'll have a slight bump in compression with the A18 head.
Anyways you need the A18 head, unless you can find a A18 with the same intake ports as the A20. Good luck.

I'm guessing about these... educated but not really.
Keihin jet size... unkown about weber equivelent...
112 main
~ 65 - 165 - 175 - 210 - 275 Air correction ???
Primary barrel stock
180 main
~ 65 - 165 - 175 - 210 - 275 Air correction ???
from what I can see 165 is the 110 jet and the 65 unscrewable jet combined... however there is one variable that changes things... I believe there is a vacuum source... a tap thru the carb body to throttle port vacuum... if i had my weber book I could compare the throttle position to signal strength at the thottle port... this would help me determin if more thottle port vacuum is increasing or decreasing the mixture... also I not that there is a tap into the idle passage... this further confuses me.
Anyways if I were to block off the ports I thought were needed... and swapped the jets to weber jets they would be as follows.
130 main / 195 main
180 air-c / 225 air-c
+ 50 ....... + 30 ( This follows the Keihins patten, however if i just add 40 to each side like for most instances when weber jets are paried up the air-c jets would be 170 / 235 )
Nottice the jet size picked for the keihin ( 130 ) is smaller then the weber jet size ( 145 ) is stock...
But looking at the keihin's design with it's very small primary choke... its my best guess that it will need less of an orrifice to pull in fuel and also will demand less fuel, while the secondary is much larger then the weber and needs more fuel and a greater orrifice because of the reduced choke.
What has me all worked up is that the idle jet may be effected... in a way I can't yet discover... I will as soon as i get my hands on another stock carb and manifold... stay tuned.

[Civvy]

O.k. Sorry to be a pain in the ass an all!
but like i said this modified STOCK A20 CARB IS MAKING THE CAR FASTER THAN THE HONDA STOCK B20 F.I.!!! so its worth me getting it right.
the jet i blocked..i only used silicon seal as a temporary bodge to test.

I'm up early in the morning to take this car to the 1/4 mile for a before then eventually after test (once its been modified)

[gampajoe]

How to? Can anybody help me with changing the dual carbs off a lude onto an accord? What is required and how to do it and last but not least can it be done?

[A20A1]

Gasket v 2.0

Here is the Gasket you can use to sort of block the Accel pump bleed... it also has more gasket material making the gasket a little more sturdy... I added material mostly on the float bowl side to reduce the gasket intefering with the air flow in the barrels... but in the primary barrel I made it very rough so you might want to fit the gasket on the car as is and crop any overhang inside the primary and secondary barrel...

I'm not sure how big a hand held hole puncher is but it should make a clean cut for the bolt holes and the other holes as well as giving you rounded corners to avoid tears.

Print @ 300 DPI

EDIT: Hmm Try printing it out at 4.75"

EDIT 2: I changed the image so it should print out okay as is at 300dpi, just double check to see that it's 4.75"

You should be able to print directly on a thin brown gasket sheet... just cut it to the size of a regular paper... and pop it in the ink jet.

[lostforawhile]

I know this is an old thread but i had something to add,someone recently told me you could interchange jets from the keihin motorcycle carbs into our carbs for our cars has anyone else ever heard of this, i understood that keihin made different jet sizes but you just couldn't buy them over here. probably can't get them in japan anymore, but if you can get a set of keinhin jets for the bike carbs ..............i wonder if it would really work?