how are they totaly different? they look exactly the same.

 

BTW- I just bought a 3.3 glass ball needle from Mazdatrix and you don't want to use their instructions for adjusting the float level. The 3.3 is longer than the stock and 300 and in the instructions they tell you to use the factory 24.2 mm height- NOT. It's best to buy a float level tool and adjust the float level with the carb off of the engine and turn it upsidedown with the guage. Takes a little time but once its done it's done. Also, I just found out right after I bought my 3.3 from mazdatrix that a volkswagen shop by my house makes a 3.3 needle with a steel ball- The best of both worlds. The website is www.geersengineering.com

 

does anyone utilize "ide by-pas circuitry" im understanding that you can get a much finer tune out of your idle and you dont have to have the throttle plates open to get an idle which gives you a smoother progression phase into your main curcuit?

 

But they're not, which is why you're having problems.

 

You always want to crack open the throttle plates as little as possible to set idle rpm. Don't idle with the plates open enough to suck fuel from the progression holes. Those holes add a lot more fuel and minimize the effectiveness of the idle mixture screws.

 

OKAY! I researched it and the IDA and DCOE jets are the same. The difference is that the IDA jets are F10 flute hole only and the DCOE jets aren't available in a F10. So if you have a F10- jet it's a IDA jet.
http://www.piercemanifolds.com/calpart.pdf
http://www.piercemanifolds.com/products.htm

 

has anyone added the 3rd progression hole for the Idle circut? I've read it's the first thing the VW guys to to an IDA.
http://www.aircooled.net/gnrlsite/re...idarebuild.htm

 

Used the internet for technical research? I don't believe it!!! I thought the internets was just for ****.

Yes I had the 3rd progression hole and fuel inlet machined by Jaycee Enterprises in Huntington Beach, on my brand new carb. Great progression circuit. My friend who had a stocker 2 holer felt the dead spot and said the 3rd hole did the trick!

 

LOL! I also called a local shop that I get most of my jets from. The front desk guy, I'm pretty sure, has a learning disability, but once you get past him and talk to a tech they're pretty knowlegeable. I'm betting with the added progression hole you could run leaner jets. Because there isn't the need for the extra fuel to get over that dead spot in the transition, it should result in better gas mileage.

 

UPDATE: LOL. I read the haynes weber book and saw that the IDA and DCOE idle circuits are in fact different and so are the jets. kinda... What I said before is true. the jets are the same, but IDA jets are F10. F10 means that there is NO flute hole. You see in a DCOE the flute hole controles how much air is mixed with the fuel in the idle circuit. In an IDA the jet holder controls how much air is mixed with the fuel, that's why there is no flute hole in the IDA idle jet. Now the idle jet holders come in 3 sizes. 100, 110, 120. I'm currently running a 65F9 idle jet and a 120 holder and it runs better than it did with the 65F10 (a.k.a. none flute) I think the flute hole is leaking extra fuel through the carb and that's why it does run better, but it's too rich. I'm going back to the 65F10 tomorrow and I'm going to order the other idle jet holders and report back on how it drives.
FYI I tune with my nose, butt, ear, and a narrow band.

 

The same...but different. Got it.

Trying the 100 and 110 idle jet holders will really help tune it.

 

http://www.ausrotary.com/viewtopic.php?f=16&t=75611
http://www.ausrotary.com/viewtopic.p...etting#p898273
http://www.ausrotary.com/viewtopic.p...etting#p696443
http://www.ausrotary.com/viewtopic.p...etting#p594731

 

has anyone here put a airfuel ratio meter on there motor?

I have a 190 fuel and a 200 air jet and my motor is running rich at all rpms from idle up. I am prob going to try a 170 fuel see what that does. or do I have to get a smaller air jet like 160? I know they are supposed to be 50ish apart.

40mm venturies
300 needle
13b 4port large street port

 

Fuel Pressure to high, floats too high, idle fuel jet too big, needle and seat stuck open can cause it to run rich everywhere. Yes, a big idle fuel jet will make it run rich across the board. I had a 75 idle fuel jet and 120 holder and it was very rich idle up to redline. 65 / 120 much better.

190 main fuel is a very good start.

smaller air jet = richer at higher rpms

 

Im running 4psi fuel pressure
float could possibly be off Im ordering a gauge to set float today.
I am also going to order a smaller idle jet. as well as a smaller fuel jet 180. Ill let you know what I end up with.

what will the idle jet holder do if I go smaller on it. right now i have 120 holder with a 70 jet.

 

Dial it down to 3.25psi. I tried 4 and it was overfilling the float bowl. And when driving up a steep hill the rear rotor ran rich as fuel sloshed to the rear of the float bowl.

The idle jet holder also is an air bleed. Smaller the number, less air bleed = richer. So you use the idle fuel jet and holder to fine tune the fuel delivery curve for the idle and more importantly the progression circuit. The 70/120 combo is too rich on the progression circuit as in 11.0 - 12.5 air:fuel ratio. I'm going to try out 65/100 and see how it goes. 65/120 is rather lean when you're cruising along then let off the gas the AFR goes up to 14-15. Which is great for MPG but the engine studders.