Large Model Association Forum

Hi everyone, I was wondering if anyone could help, a while ago a bought a great planes large extra 300 without the engine this winter I was thinking of setting it up, I have a 30cc petrol engine with the carb mounted on the rear and if I was to fit this I would have to cut a hole in the firewall to accommodate, so the carb would end up in the fuselage,
Is this a problem?
Thanks in advance
Ross

Hi
Hope this helps
If the complete carb is inside the fus it will monitor the air pressure inside the fus and regulate as required.no problem
How ever if the carb has a bell mouth extension fitted and the carb body is out side and the bell mouth is drawing air from inside .you need to make the fooling mod.
If you look at the silver plate on the bottom of the carb( held on with four screws )you will see a small hole. This hole lets air in to regulate the carb, so what we have to do is solder or epoxy (or both) a piece of fuel pipe size tube into the hole about a 25mm long
Then fit a piece of fuel pipe to it ,and run the pipe into the fus and support it inline with the end of the bell mouth extension. The carburettor which is still out side the fus now monitors the air inside the model,
If you do not do this mod the engine will still run well on the ground but will run rough and properly stop as you again height.
Guess how I know
Good luck
Arthur

thanks for you quick reply, ill keep that in mind
happy flying
Regards
Ross