well the 65f9' are on they're way and i just checked my ac pump and the jet is a 45 i think i need to go bigger what do you suggest?? prolly 65

 

 

You are runing 3.5 psi's on a DCOE? The Weber/Dellorto book I have calls for 2.5 with no less than 1.5 at full throtle.... for all DCOE Carbs. I used to have mine between 3.5 and 4.5 and it use to flud all the time...


Anyone has the complete list of jetting for a street port 12A with a 45DCOE????

 

Anyone know the setup for a stockport 13b? I will be putting my 45 DCOE on a stockport 13b (S4) this month and dont know what to set all the jets at. I also have a Holley FPR that i am selling if anyone is interested. Never been used i bought it from Sorrow. $25 bucks shipped.

 

well i'm trying to figure out the stock port 13b set up. I'll let you know what works out in the end...

 

any of you guys bought an air/fuel ratio gauge yet? Well worth the $$ and makes tuning a carb less guesswork and more of a science!!!!!!!!!!

Just trying to help out. I use a Halmeter/30 by twminduction.com

 

Ive found that at sustained full throttle at around 100 MPH in 5th my car runs REALLY lean and starts detonating going down the track... Im not sure if my fuel pressure is dropping off, or if the gas just isnt getting into the carb ort what, but I dont like it, lol.

Also, my accelerator pump is also a 45, I thought about trying a 65, but never did, lol.

~T.J.

 

do you have a 65?? and what fuel pump are you running and regulator? and pressure? And I've got a autometer air/fuel ratio gauge

 

ok. you should be running around 4.5 psi of fuel. that may varry unless you have a calabrated fuel guage. every engine is different, thare are other things ti take into account like climate and altitude. at sea level over here on the east coast a f7 e-tube with a 170 main and a 160 air bleed work on my se. im not sure on my idle jet cause i just drilled it out till it worked right. oh, im also running a 36mm choke. hope i helped atleas a bit

 

Where is a good place to learn about jetting webers? I'm going to buy one sometime soon, but im a total noob when it comes down to the jetting. Cause i dont know what f8, #45, blah blhab stuff means.

I have to know everything about what im doing before i get into it.

 

if you want to learn about carb basics, go to paul yaws web site. mazspeed.com has a real good article in its facts section

 

i have read that. i was just wondering if anyone knew of a page that is more weber specific? Thanks though. i will probably read it again to refresh my memory.

 

amazon.com

search weber dcoe and you'll find the book by hammel, title starts with 'how to rebuild and pwertune weber dcoe and dellorto dhla sidedraft carbs' along that line.

i bought it, FANTASTIC BOOK.

 

i bought it. it only helps taking the thing apart if you ask me...

 

Nope, I dont have any 65s. If I did I would just try them real quick, lol . Im using the Carter 7 PSI street/strip pump through the Holley 1-4 PSI regulator set at 3 PSI for now. I have a problem with fuel starvation (detonation) when accelerating floored from 80 to 100 MPH in 5th gear, I dont know what thats all about, but I need to figure it out. Maybe I need a bigger inlet valve?

~T.J.

 

Myabe the carter is not enough fuel pump. I have the stock pump with the pralator regulator, and when i went to drag race the other day i was having mad lean surges at the top of 4th gear with the fuel pressure set at 3.5 then i put it up to 4.5 and they weren't as bad. I think the answer is the holley blue. I guess you get what you pay for... So i'm gonna get a big ole' fuel pump :evilgrin"

 

I have a 12A Street Port and am using the following:

45DCOE with:
Chokes=40
Auxilliary Venturi=4.5
Main Jets=230
Idle Jets 60F9
Emulsion tubes=F11
Air Corrector 170
Acelerator Pump Jets=45
Fuel Presure at 2.5psi no less than 1.5 at full throtle...

 

Hi guys,

so I will shortly be attempting to tune my weber, I have a stock port 6port 13b in my 86 rx-7, with gutted stock exhaust, and am using stock lower intake manifold with RB upper. I have a weber 48 dco and I have done a 2 hour search looking for a good example to go by but it seems like everyone either has a street port or a 12a! I'd like to see what you guys think about my setup! In terms of jetting,

It seems like the 65 f9 is a quite common idle jet..where do I go from there? The one example I did find was the following (copied)

F11 w 180 main
160 air correction

ps, Right now I have 38 and 42 mm chokes, and about a million extra idle, main etc jets, I also am located in Flint Michigan, near detroit at the moment. Thanks for any help!

Gus

 

ok guys here goes..... without coming off condescending I wanna try to steer you guys in the right direction. I won't be able to give you hard fast numbers for jetting sizes for a DCOE for the simple fact that I've never run one... I'm currently running a Mikuni PHH44, but have also tuned a Weber IDA with great success using the same general process.

Firts off, you CAN'T tune a carb with incorrect fuel pressure or float levels. Your first course of action should be to get a fuel pump that will flow enough; a holley red should be fine for most street applications, and a carter will work as well. Holley Blues are usually only necessary for boosted aplications or BP's or PP's. More fuel is not always better. Secondly a regulator and guage are NECESSARY!! Billy from Respeed is known to have pretty much the only accurate fuel PSI gauge, as most aftermarket guages are known to be notoriously in-accurate. Remember that theese carbs need low-pressure and hi-flow, not the reverse. Generally speaking a higher pressure equates to lower flow which would explain the previous poster mentioning running out of gas at the top of the track at the drag strip. My recomendation for him would be to lower the fuel pressure and try onther pass, it should improve. As for regulators it's a matter of personal preference, I use a Holley with no complaints, but others have complained of poor reliability and recomend the Mallory unit or others. The brand is not nearly as important as proper range, and ease of adjustability. Once you have all theese bases covered then move onto setting the float level.

The float level is most detremental to part throttle cruising... and improper adjustment can most often be felt at a steady state cruise. Best described as a buck/miss/kick this is caused usually by the float level being too high and excess fuel spilling through the emulsion tube pick ups and into the carb in the form of raw gas rather than atomized vapors. This immediately cause an extremely rich condition and fouls out the spark and causes the before described miss. The only way to adjust the float level is after tunning fuel pressure. If the level is too high the above mentioned "miss" will be felt, if it is too low the float bowls will run out of fuel in the upper RPM ranges. Adjust the level accordingly, by raising/lowering it and driving the car. If lowering the level, first check for part throttle cruise, also known as the 3K RPM stumble. If the stumble is still there then lower the level more, and recheck. Continue this process until the stumble is gone and then check for high rpm leaning. Drive through first and second gears and put it in 3rd and floor it, let the car pull all the way through until it either hits redline or begins to run out of gas. If it pulls smotthly through redline then you're done, if it leans out then raise the level until you can make it all the way through the revs in 3rd. The trick here is finding the perfect level... remember you're dealing in millimeters here, so it make take a bit of trial and error to get it right. If the fuel level is too low then reverse the process....

Once you get theese variables covered then take Robert's recomendations for a starting point for jetting. This will get you in the ball park for tunning the jetting. It's important to remember that if you're engine is ported then you most likely won't be able to use some off the shelf jetting numbers because each port is different and has different flow characteristics.

Hope that helps...

Ken

 

12A Street Port
Steel Lightweight Flywheel
MSD SCI Ignition Box on Leading Ignition, Coil on Plug Setup for Leading with Jacobs Super Coils

Stock Ingnition on trailing with MSD Blaster Coils to Ignition Distributor

45DCOE 152 Series Weber Side Draft
Idle Jets 65F8
Main Jets 165
Air Corrector 230
Emulsion Tube F15
Pump Jet 4.5
Chokes 40mm
Auxilliary 4.5
Needle & Seat 300
Fuel Presure @ 4.5psi with a Carter Fuel Pump
vacum Advance Disconnected and ignition timing advanced about 5 deegrees +-


Max Power 167 at Flywheel
Max Power 137 at Rear Wheels
Max Tork 140

Runs Great with this setup....

 

my old thread
https://www.rx7club.com/showthread.p...=OER+stockport

 

i have a 45 sidedraft, how do you check the jets? just remove the cover?

also any recormendations to what jets i should have on a street port 13b 4 port

thanks
Mark

 

i've got one, but have never tuned it. not too good with all the jets and emulsion tubes and such.

 

The jets are right under the circular cover with the gold tab that you can twist off by hand. Use a flathead to unscrew and pull out the 4 jets. The 2 larger ones are your mains, the smaller ones are the idle jets. For the mains you can pull off the top of them (the part that has the slot head and is threaded) and then you will be holding the top in one hand, and the other long piece will be your air corrector, emulsion tube, and main jet (oriented from top to bottom). They will all pull apart from one another (you may have to use pliers if they are gunked up) and should each be stamped with their sizes. The idle jets are just two piece, the bottom slides out from the top and it should also be stamped with the size. To find out the size of the choke tubes you will have to take off the air horns and loosen the screws on the underside of the barrels so that they will pull out from inside the barrels. They should be stamped as well.

 

thanks
if i pull the jets and choke tubes out will it change the settings it currently has? (idle and mixture?) im just going to check these and put them back, may try a different set up before buying a 48IDA
i am looking at a 48ida can anyone recormend jet sizes and chokes for 1 on a 13b 4 port street ported?

many thanks
Mark