Fuel Line and Primer Question

[henrysamson]

I am building a model IV w/ Rotax 912. Where have others put the fuel line pass through fitting on the fire wall? My manual does not mention a location. I was thinking placing it in the center at the top of the bottom part of the fire wall. Just below the horizontal cross tube. Then have the "L" fitting point to the right and slightly up to run the fuel line to the fuel pump.

Also, I have the primer kit. Is it worth installing?

Thanks again!

[HansLab]

I have a gascolator bottom right side of the FW.
Putting the fuel pipes through where you stated will perhaps give you trouble later: there is little space between FW and engine, adding a gascolator there will be hard...

[henrysamson]

There is a photograph in my manual showing just that. But, my manual does not mention a gascolator nor was one supplied. Fittings were provided for the firewall that allow attachment of the flared aluminum fuel line in the cabin side and the flexible hose on the engine side and an inline fuel filter. I wonder if they changed the FWF package at some point but only partially updated the manual. I got my FWF in 2001 and I have the plastic header tank with a fuel drain.

[HansLab]

I can't help you on that one, for I bought my IV as a project - and the gascolator was allready build in. It is an AirSpruce http://www.aircraftspruce.com/menus/ep/gascolators.html
Hopefully this helps.

[HighWing]

There have been discussions on the gascolator and opinions vary. Some feel that the header tank behind the seat being at a low point acts as a sump and debris and water can be drained there. Others like the gascolator and have valid arguments for their opinions as well. In thinking about it, the early kits included a gascolator, but the header tank was mounted high behind the baggage sack and it was definitely not the low point of the system. I think Hans has a valid point regarding space in the center behind the engine. It is tight there with the oil tank and there might be other things you might want there. On my first Model IV with gascolator, I ran the line through the firewall at valve height on the right side. On the current project, I ran the line, again at valve height, but on the left side. The reason for this is that I put the battery on the right side behind the firewall this time rather on the left side. the thinking on this is that I most often fly solo and just tried to distribute the weight a bit better and the battery becomes a big barrier to work around.

Another thought on the center location. The newer models mount their heater core in the center with the inlet and outlet fittings through holes in the firewall. this set-up eliminates the coolant lines wandering around above the pilot's feet which, as has been mentioned, might be a potential burn risk. After helping with a friends Outback with the new location, I did the same on my IV and like the set-up, though I don't know if it will work with the factory mount and oil tank there. I have a custom engine mount that added an inch or two behind the engine and put the oil tank on the right side - another reason for the fuel line on the left. As I finish up my new Model IV, I am becoming increasingly aware that one simple modification will likely impact something else. I have lots of mods and they have on occasion resulted in other mods to make them work. Something like taking a pill to handle the side effects of another pill. Thank goodness for the manuals. All the potential conflicts were experienced and fixed. Then guys like me come along and try to reinvent the wheel.
Lowell