1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

need a bit of help with 45 DCOE

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Old 10-25-09, 11:27 AM
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need a bit of help with 45 DCOE

Spec:

Stock 12a with stock fuel system
65F8 idle jets
F16 e-tubes
155 air jets
170 main jets
45 pump jets
36mm choke tubes.

I got the car idling pretty much perfect at 1k rpms. I can start the car without a problem without the choke when the cold or hot (no difference it starts right up almost feels like it was EFI). My problem is when I press the gas pedal it bogs and it dies. If I press it gently I can get the car going and rev all the way to red line. How can I get the bogging to go away?
Old 10-25-09, 12:14 PM
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A 55 pump jet might help you out.



Although I really wouldnt recomend running the stock fuel pump.

Aside from that your main circuit might be a bit lean, but it shouldnt bog right out and die.
Old 10-25-09, 12:22 PM
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Originally Posted by Gen1onr
A 55 pump jet might help you out.



Although I really wouldnt recomend running the stock fuel pump.

Aside from that your main circuit might be a bit lean, but it shouldnt bog right out and die.
would you elaborate please, I'm new to carburetors. What does main circuit means?

I was told that stock fuel system should be okay with a complete stock 12a by Robert at Rotary Shack. I do plan on upgrading it when I get my exhaust replaced.
Old 10-25-09, 03:53 PM
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Can i get some recommendation which jets I should change?
Old 10-26-09, 12:55 AM
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it sounds to me like the accellerator pump isnt working at all since it will make redline if revved gradually, but dies if you gas it quickly. Check to make sure the accellerator pump is working at all, and if its not, check the diaphram and try blowing out the jets and passages with carb cleaner and compressed air. If the pump is working then you may need to adjust when and how much it pumps by changing the pump jets or adjusting the linkage.
Old 10-26-09, 05:24 PM
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Well got the car on the road. Still sputtering/bogging when pressing the gas pedal but it just initially but it goes pretty good after that. I'm going to getthe fuel upgrades since I notice some knocking at about 4k rpms at half throttle.

Another problem surfaced today when I was on the free way, all my instrumentation quit working but the speedo. My blinkers don't work and overdrive switch either. Radio and ac still worked and so did the instrument lighting. I think I know what it is though.
Old 10-26-09, 07:23 PM
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Stock 12a with stock fuel system
my recomendation
65F9 idle jets
F3 e-tubes
155 air jets
185 main jets
45 pump jets
36mm choke tubes.

Your biggest problem is the idle jets. take those 65f8's and throw them in the trash. they will never come close to working in any rotary application. 65F9's will cure most of your problems.
Old 10-26-09, 07:48 PM
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Gracias My hermano.

Going to try something else first that got recommended to me. If that doesn't work then I will change jets.
Old 10-26-09, 08:03 PM
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Originally Posted by Gen1onr
A 55 pump jet might help you out.
This.

Don't mess with anything else until you try it with bigger accel. pump jets. I guarantee that's 90% of your problem.
Old 10-26-09, 09:36 PM
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Originally Posted by PercentSevenC
This.

Don't mess with anything else until you try it with bigger accel. pump jets. I guarantee that's 90% of your problem.
agreed. the largest of your problem is most certainly related to the function(or lack thereof) of the accel pump. Larger jets for the pump, and make sure its working at all.
Old 10-27-09, 05:34 PM
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I drove to work on Monday and I was noticing it was getting a bit easier to drive and the sputtering wasn't as bad but still there.

Got recommended to just remove the pump jets. I did and the sputtering got slightly worst. I put the jets back in and drove it back home. I notice that the sputtering was getting better. Also notice the knocking was gone for the most part. So could be that the jets need just some cleaning? I'm going to try that this weekend and see.
Old 10-27-09, 05:35 PM
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It's your idle jet. the 65f8 is way wrong. You can't use anything from the f8 series they're way too lean.
Old 10-27-09, 05:46 PM
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Voy a pedir los jets que tu recommendastes tambien.
Old 10-27-09, 05:48 PM
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F8 is only one step leaner than F9. The 50F9s I'm running are much leaner than 65F8s.

Try cleaning your pump jets, but you may need to go up a size or two.
Old 10-27-09, 05:50 PM
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Got a feeling that my jets are not my problem but I might just order new ones any ways.

How do I make sure my pump is working properly?
Old 10-27-09, 05:58 PM
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Look down the carb and play with the throttle linkage. You should see a healthy squirt down both barrels from the accelerator pump.
Old 10-29-09, 11:54 AM
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Prett sure my accelator pump isn't working. I can't get a clear view of the barrels. It just the more I drive the car the more sence it makes. How and what should I do next?
Old 10-31-09, 12:57 AM
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the flute hole on the idle jet comes into effect at the top of the idle circut. F8 is too damn lean. i ran 75F8's when I was being stuburn and not listening and it was still getting 20:1 (off the map) AFR's at the transition with my old na 13b 45DCOE setup. You cannot use f8 idle jets in a rotary weber and expect it to drive well. Just buy 65f9's and stop wasting your and our time. I'm serious. Now i see why Robert never answers questions anymore. noone listens when you tell try and help them. what is happening is when he opens the throttle it's bleeding off too much air through the flute hole since the f8's are 1mm and it's not getting enough vacuum signal to pull the fuel through the idle jet. Now when he's slow on it he can get the main circut to come on and get him over the huge leanspot the circut has right now. the f9 flute size is .8mm much smaller. and will allow for more of a vacuum signal to reach the opening at the idle jet and give him more fuel. just try the idle jets and i can almost gaurentee that it will get much better.
Old 10-31-09, 05:01 PM
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I ordered some new jets including idle jets. My accelator pump is fine, beside seing it you can hear it a mile away squirting fuel.
Old 11-07-09, 05:43 AM
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Idle jets were my problem. Had to re adjust my idle settings a bit but the throttle respose is really nice now. Thank
Old 11-08-09, 01:28 PM
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Originally Posted by Hyper4mance2k
Stock 12a with stock fuel system
my recomendation
65F9 idle jets
F3 e-tubes
155 air jets
185 main jets
45 pump jets
36mm choke tubes.

Your biggest problem is the idle jets. take those 65f8's and throw them in the trash. they will never come close to working in any rotary application. 65F9's will cure most of your problems.
Hyper4mance2k- I see you are in Seattle, I'm across the water near Bremerton. I'm about to begin putting together my 7 and I have a 45DCOE, stock porting, RB style stainless header and Gilmer drive. The carb is new old stock and has factory jetting. I know I'll need to get new jets/chokes etc. Would this be the setup you'd recommend for our NW area driving? Any other pointers or special considerations for building a 7 for driving up here?
Thanks a load!
Ray
Old 11-08-09, 02:19 PM
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If you need any jets I have a full set from my stock carb. The Carbs junk but the jets are all clean.
Old 11-08-09, 05:47 PM
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Originally Posted by hondasr4kids
Idle jets were my problem. Had to re adjust my idle settings a bit but the throttle respose is really nice now. Thank
Did you run a stock carb before?? How do you like the 45 compared to the stocker...if you had a stocker... driveability, power, etc.
Old 11-08-09, 07:02 PM
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My stocker never worked well enough to make a comparison. Reason why I got fed up with them and went with the Weber. When I took the manifold off to install my Weber manifold, I found out the reason why my stocker wasn't running right. My coolant o-ring was busted and coolant was sipping into the rear rotor.
Old 11-08-09, 08:23 PM
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Originally Posted by hondasr4kids
Idle jets were my problem. Had to re adjust my idle settings a bit but the throttle respose is really nice now. Thank
lol... I win. again


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