What Fuel Do You Use

[chappers]

you buy it phill and we buy from you?

[scorchio]

Magnum and OS50

I have just been trying the 12% Magnum fuel from Skyline.
I cannot get my engine to run properly on it.
I took my A test on Sunday 18MPH wind did not help, and I had to restart my engine over 10 times. It would idle but would not transision.
I have the mixture screw at the stock setting and the main needle 3/4 of a turn out from closed.
The engine does not get hot and there are masses of smoke.
Any ideas on where I should have the needles?
I have a raptor 50 with the stock muffler.
The OS has had over three gallons through it.

I passed the A but flying two eights at walking speed in the wind was a challenge to say the least.

[Stuart]

Firstly, congrats on the A cert.

Two things spring to mind here when idling the pinch test is a good judge of an engines tuning. See below quote from Raptorite in a previous topic.

Topic Link click Here

It is also a good idea to do what is called a "Pinch Test" at this point too, this basically checks that the idle needle (screw inside the throttle barrel) is set correctly and is done in the following way;

1. Start the engine and allow it to warm up on tick over for about 30 seconds.

2. Using either a fuel shut off clamp, or your fingers, stop the flow of fuel to the carb by squeezing the fuel pipe closed. If the engine runs for any more than 2 seconds before it speeds up and dies then the idle needle is set slightly too rich. If it speeds up and dies straight away it is slightly too lean.

3. Using the results in step 2 above adjust the idle needle in very small amounts either clockwise to lean it, or anti clockwise to richen it.

4. Do step 2 again until the engine ticks over for 2 seconds normally before speeding up and dieing.

Your idle needle is now set perfectly, so as long as you have a nice consistent run and plenty of smoke, youre fine

Secondly, have you checked all the fuel lines to make sure that no leaks, importantly the one in the tank if erroded will cause an varied fuel flow causing running problems. I'm assuming its an OS No.8 plug ?

[scorchio]

Needles

I tried the pinch test and it ran for around 6 seconds.
I will lean out the bottom end and try again later.