My flying site is very dusty. Where can I find some air filters for the carb. How do I make some home made ones.

My other question is with regards to the wire from the ignition box to the spark plug. The wire that is on the outside, braided wire. What is it for? Mine has been partially cut by rubbing against the cowl. The engine now is not that smooth. Is it due to this wire being partially cut. I though this wire is only a sheild against RF interfearance.

Haris,


The braiding is intended to suppress RF interference.
The rubbing of the braid has probably damaged the insulation, or caused small strands of the braid to perforate it.

This may allow the spark to 'jump ship' and to ground to the braid, not materializing in the combustion chamber, where it should.

Your rough running may be a result of this, but it could also result from other causes; carburettor mis-adjustment, or dirt in the fuel passages, for example.


You will have to improvise about an air filter, since it is currently not offered by MVVS.
But you can try to contact the Walbro company, which manufactures the carburettor for countless engines, for a suitable filter.

Is it ok to tape up the braided insulation wire completely with electrical tape? Should I get a new wire? I am getting rough running at above half throttle. It may be because the high speed needle is too lean. But this seems to happen only in the air.

Haris,


Your ultimate solution is to replace the wire, since with 20,000 Volts, insulating tape is not really an insulator.

The high speed needle on your engine should be set a little richer than peak, to allow unloading and speeding of the engine, when flying at speed.

If it exactly peaked on the ground, it could become too lean in flight.
Too lean a mixture will often result in 'missing' and rough running.

I think you are right the high speed needle is too lean and I am replacing the wire. Thanks