switching 912 intake manifolds question

[avidflyer]

Hi all, well I finally got around to working on the Kitfox 4 again. I built the firewall, and mounted the 912 engine. I have the engine section in my manual for the 912, in fact I bought it seperate from Kitfox a year or so ago, as my kit came with no firewall forward. I see it calls to switch the manifolds around to spread out the carbs further. I skimmed through and was not able to find the reason. I see that if I line the carb throttel linkage up with the firewall, it comes close to some of the tubing of the fusaloge, was that the reason for moving the carbs? Also, the manual talks about building a different ignition module mount, but the page that shows it in my paperwork is blank. The page # is 69 date- 06/06 Rev. A
Model IV The figure is L-3. Ignition Module Mounting. can anyone scan it and send me that page? Thanks,
Jim Chuk
Avid MK IV (flying)
Kitfox 4 (building - again)
Northern Mn

[sdemeyer]

Hi Jim, I believe the main reason for switching the carbs around is to make it easier to adjust the throttle linkage. It looks like a nightmare to adjust the linkage when it is on the inside of the carb. Some people install the ignition modules on the motor mount to reduce vibration on the modules, lessoning the chances of module wires breaking.

[Slyfox]

you switch the manifolds to gain room for the oil tank. The oil tank goes in the motor mount which is in the top center of the engine. You have to also move the electronic ignition module, you hang it on the tubes of the engine mount on the right side of the airplane by the oil tank. You will also end up rerouting the water cap and doing a little rework of the hoses.

[lowerjon]

Cold air intake is mainly a device which brings comparatively cooler air, to the car’s internal combustion engine, and thus, increases the engine power and efficiency. Air intake systems contribute to a substantial increase in the horsepower. This is an inexpensive way to increase the efficiency of your car engine.Cold air systems have four parts. They include two mandrel-bent aluminum piping, one billet-aluminum MAF adaptor and one high flow filter. These systems generally tend to add 3-5 horse power, to the engine. The sound wave generated by an intake system and its frequency varies greatly, depending upon the length of the system; the longer the system, the lower the frequency. With all the usual intake systems, as the RPM increases, the inlet valve opening also increases accordingly; but the length of the inlet tract remains constant throughout. k & n cold air intake (http://www.airintakeandfilter.com/)let me know, if you need the MAF, i maybe able to get one directly from Bosch

[mr bill]

I need a copy of page 69 from 06/06 rev A or figure L3 for the ignition module mounting bracket. I did find a picture of the bracket for the Rotax 503, but I don't know if that would apply.

[P Morel]

:cool:By swapping the intake on the 912 to allow room for the oil filter seemed like a quick fix but created a big problem for the carburetors. With the carbs further away from the center line of the engine block, there is a tremendous amount of vibration. Also with the fuel in the carb bowl not sitting level on tailwheel aircraft during start up, taxi and shut down, vibrating carbs, this is why we sometimes get fuel vented out the carburetors. Raw fuel in the engine compartment can sometimes lead to engine fires. Also, with the additional vibration due to swapped intakes, the float needle valve wears much quicker than normal and a carburetor overhaul is needed.

Sure wish there was a economical fuel injection conversion for the 912. :cool: