Qjet Question

[Robert Simpson]

Update. Removing the spring on the secondary shaft and pinning it was the key. I made a pass last weekend and drove past the finish line and pedaled it a couple times and it worked. I dial honest but now I know if I need to pedal it should respond ok. Thanks to all the suggestions it is appreciated. Now if I can just figure out how to lean up the mid range it would be good, any suggestions out there on that?

Robert

[Mike Pearson]

Originally Posted by Robert Simpson

Update. Removing the spring on the secondary shaft and pinning it was the key. I made a pass last weekend and drove past the finish line and pedaled it a couple times and it worked. I dial honest but now I know if I need to pedal it should respond ok. Thanks to all the suggestions it is appreciated. Now if I can just figure out how to lean up the mid range it would be good, any suggestions out there on that?

Robert

Are you still using the metering rods in the primary jets. If so most are not using them any more. Drop down about 5 jet sizes on the primary jets and remove the primary metering rods and plug the hole where the power valve used to be. That should give you better control of the fuel metering

[Robert Simpson]

Originally Posted by Mike Pearson

Are you still using the metering rods in the primary jets. If so most are not using them any more. Drop down about 5 jet sizes on the primary jets and remove the primary metering rods and plug the hole where the power valve used to be. That should give you better control of the fuel metering

No I'm not using the primary rods. I did drop down as lean as I can (65), that is as lean as I got. My carb is rich down low and mid range and slightly lean up top. Any idea's on how I should approach this? Thank's again.

[Hacksaw]

Try a smaller main jet to lean it early in the run, although a 65 should be lean enough. Make sure the primary plunger cavity is plugged. Put a thinner metering rod in to richen it up at the top. What rods are you using now?

[Mike Pearson]

Originally Posted by Robert Simpson

No I'm not using the primary rods. I did drop down as lean as I can (65), that is as lean as I got. My carb is rich down low and mid range and slightly lean up top. Any idea's on how I should approach this? Thank's again.

Check the plugs on the bottom of the carb body with the base plate off to make sure the plugs are not seeping. That will richen up the idle and low end if they are leaking. put some JB weld on them just to make sure. Also check the float level and fuel pressure. 6.5 lbs should be more than sufficient. I also put a 90 degree spark plug boot on the vent tube facing forward. Do you have electrical tape around the secondary metering rods to control slosh that can splash up around the secondary rods? My cab has a small plate that fills the area around the secondary metering rods but you have to mill the bottom of the carb top for the plate to move freely. What rod size are you running in your carb?

[Randy Schonscheck]

Originally Posted by Mike Pearson

Check the plugs on the bottom of the carb body with the base plate off to make sure the plugs are not seeping. That will richen up the idle and low end if they are leaking. put some JB weld on them just to make sure. Also check the float level and fuel pressure. 6.5 lbs should be more than sufficient. I also put a 90 degree spark plug boot on the vent tube facing forward. Do you have electrical tape around the secondary metering rods to control slosh that can splash up around the secondary rods? My cab has a small plate that fills the area around the secondary metering rods but you have to mill the bottom of the carb top for the plate to move freely. What rod size are you running in your carb?

What does the 90 degree spark plug boot do? Pinning the shaft is always a good idea for all the reasons listed.

[monte385]

Originally Posted by Robert Simpson

No I'm not using the primary rods. I did drop down as lean as I can (65), that is as lean as I got. My carb is rich down low and mid range and slightly lean up top. Any idea's on how I should approach this? Thank's again.

Are you allowed to use screw in air bleeds?

[Robert Simpson]

Thanks guys for the suggestions. This is a 77-78 model carb that I use on my street car/footbrake car. I do not have primary rods in it. I have been playing around with it to make it better for what I am doing. I can put air bleeds in it if I wish. My main question is what part of the carb helps deterring the mid range fuel mixture? I am asking if the air bleeds in the main body would have the largest effect on tuning the fuel curve in mid range? In my case 28-4000. I did discover that I have to much total timing so that prob is contributing to the slight lean occurring up top. I am working on the dist to fix that. Thanks again.

[monte385]

Is it a dual main air bleed or single?
Have you checked in here?
http://racingfuelsystems.myfunforum....989c4839377ee5
See if you can get Tuner's attention, wealth of Qjet knowledge.