PLAINCRAZY

I CANT SEEM TO GET MY ENGINE OVER RICH. I HAVE AN OS 91 WITH BVM FUEL MIXTURE.I PUT ALL NEW TANKS,FILTER AND TUBING.I HAVE THE FINGER AJUST ON THE MIXTURE CONTROL ALMOST ALL THE WAY OUT, AND THE MIXTURE ARM FULL RICH.
DOES FUEL TUBING SIZE MATTER?? IT DOES HAVE A VAPOR TRAIL OF FUEL AT FULL THROTTLE BUT THE MIXTURE CONTROL DOES NOTHING WHEN I LEAN IT OUT AS IT SEEMS TO BE AT FULL POWER ALLREADY.I AM AFRAID IT WILL OVERHEAT ONCE I AM AIRBORN. ANY ADVISE I WOULD BE THANKFUL FOR. TODD

Jim Abarno

My Feedback: (1)

I had the same problem. Make sure your fuel system is tight ( not sucking air ). I also went to large fuel tubing, and changed back from Pitot pressure to tuned pipe pressure to pressurize fuel system. Do not fly your A/C this way, your mixture will only get leaner and the engine will overheat!! I also added a 2 oz. hopper tank.

regards Jim

J. Campbell

My Feedback: (31)

What kind of fuel are you using? Definatley use the large size fuel lines, Also is your pipe pre-tuned or is this a byron setup?

joeflyer

My Feedback: (48)

You didn't say what kind of pressure you were using, but you shouldn't be using anything less than LARGE fuel tubing. If you are are using fan (or pitot) pressure you will need EXTRA LARGE tubing both on the pressure side and on the fuel side.

Also make sure your brass tubing on your fuel tanks aren't too small, they should be the same as your hose id.

Joe

PLAINCRAZY

THANKS FOR YOUR ADVISE. I HAVE A DYNAMAX FAN WITH A BVM TUNED PIPE WITH THE AIR PICKUP IN THE FAN UNIT.I AM USING 5%WILDCAT FUEL.I WILL CHANGE OUT ALL FUEL TUBING TO LARGE AND AIR TUBING. IF THAT DOES NOT WORK THEN I WILL TRY CHANGING THE AIR PRESSURE TO THE PIPE.
THNAKS AGAIN TODD

J. Campbell

My Feedback: (31)

one more thing that may be overlooked, make sure the pressure pitot is canted INTO the air flow at an angle. If it is in the fan pointed "straight ahead" it will not get as much pressure. russ

MiragePilot

My Feedback: (6)

I would like to emphasis the advice that Russ provided above regarding the pitot pressure tap orientation. The instructions that accompany the JMP pitot pressure hardware are somewhat confusing/unclear in their description of the technique to correctly align the pitot fitting. It is quite possible that your pitot probe is not oriented correctly, and as a result, you are not getting the expected level of fan pressure.

Peter

CARS II

My Feedback: (7)

If you decided to keep the fuel tubing with the large fuel lines like I did, add this to the brass tubing, Du-bro part # 813 1/8" ID fuel line barb. It will allow you to mate the large fuel line with the fuel tank tubing, it does not take to much to keep them in place.


Carlos

rcpete347

My Feedback: (251)

HI all ,one thing a lot of people overlook is the O ring on the low end , if it is old it will shrink and let the needle vibrate closed .
Thanks Rcpete

joeflyer

My Feedback: (48)

The easiest thing for you to do is disconnect the pressure line from the fan and connect it to the pipe. Some like it but I have never been satisfied with fan pressure. The bottom line is that it's finicy. Everything has to be just right and because it doesn't provide much pressure you are limited as to how much enrichment you can add.

With pipe pressure you have full range of authority to adjust it from too lean to too rich with your radio knob. There is no need to mess with it every time the weather changes.

Joe

PLAINCRAZY

THANKS AGAIN FOR ALL OF YOUR IMPUT,I KNOW ALOT MORE THAN JUST 24HRS. AGO. THANKS AGAIN I WILL LET YOU GUYS KNOW HOW IT GOES.TODAY I WENT TO LARGE FUEL AND AIR LINES.I WILL TEST IT TOMORROW, BUT IT SOUNDS LIKE I AM GOING TO HOOK THE AIR TO THE PIPE FOR MAX. PERFOMANCE AND RELIABILITY.ANY MORE IMPUT I WILL TAKE. THANKS TODD