Electrical Wiring

Been quite awhile since my last post.  I heard a rumor that the electrical part of the project can take the longest, and I'm a believer.  Seems like every operation requires a phone call, as this stuff is just so new.  I started with the battery and worked downstream from there to the starter solenoid.  The engine compartment is completely wired.  I've got the Dynon Skyview engine monitoring module installed and all of the engine sensors wired to the wiring harness provided.  I'm currently working on wiring the gps and transponder to the Dynon display.  Here are some pics of the mess of wiring...

Rotax Carb Mechanical Synch

I adjusted each carb so that each has the same power setting at high and low throttle.  This is important because each carb independently operates 2 cylinders and, if not in synch, excessive vibration will occur.  Procedure:  Advance throttle levers to full, then back off so that you can insert a snug feeler gage into one, then adjust ferrule on the other throttle cable such that the same feeler gage is snug.  Next pull throttle all the way back to idle.  Ensure that at the idle stop, no gap exists between carbs.  If so, adjust idle screw so that they are the same with no gap. 

I've got them set and will go with these settings at start up.  If excessive idle, I will back off each idle screw same amount, e.g. 1/4 turn.  If vibration still occurs, there is a way to synch carbs pneumatically by hooking up pressure gage and making sure differential pressures in intake manifolds are the same. 

Rotax Engine Mod: 2000 TBO

Found service bulletin SB-912-057UL for the engine which increases the time between overhaul (TBO) from 1,500 hours to 2,000 hours.  All it entailed was switching out an oil pump plug screw and pressure spring.  A metal ball was reused.  Following are some pics.  New unit on right. 

Control Cables Install: Throttle, Parking Brake

Here is a pic of all of the push-pull knob control cables installed.  Still have to finish up the choke cable.

 

Next pic shows the control cables behind the instrument panel.

Next pic shows the throttle control cables installed to the throttle lever.  Set screws were loctited into the lever to hold the cables.

Here is the throttle cable installed to the throttle lever on the carb.

Finally, here is the control cable configured to the parking brake assembly...

Fuel System Install: Firewall Forward

The fuel system is complete forward of the firewall.  The pics below are sequenced in the order that the fuel flows.  The first component installed was the gascolator, which acts as a fuel sediment trap and screen.  The fuel flows into the bowl from the top elbow and then out through a screen near the top and out through an elbow on the other side.   Note the spring-loaded valve on the bottom.  The unit is mounted on the firewall.

The auxiliary electric fuel pump is mounted on cushioned clamps to the engine mount.  I'm told it's a diaphragm type pump which offers little restriction to flow when not used.  Note the black fuel lines housed within firesleeve.  The firesleeve is capable of withstanding direct flame for up to 15 minutes.  The fit was snug between fuel line and sleeve, so I clamped both hose/sleeve via single clamp to the hose-barb fittings.

Next component installed was an in-line fuel flow sensor from Dynon.  This was installed where a fuel filter would normally go; however, I did not install the filter based on recommendation from Rans that there are issues with it being compromised by ethanol fuel additive.  First pic looking down and then up.

Next a connection is made at the rotax supplied line...

...And the that line runs to the mechanical fuel pump.  First an overview shot and pump housing closeup...

From here fuel is pumped to the bottom of the banjo junction fitting, mounted on the compensating tube.  Following pic also shows return line on top running to the gascolator.  A fuel pressure sensor from Dynon was installed where a plug was located in the fitting.  Rans indicated their supplied sensor has been shown to be erratic. 

Here is view from top, which also show the smaller two lines running left and right to each carb.

ADDENDUM:  After talking to Rans and spending several days in deliberation, I decided to redo all of the fuel line connections and clamp the fuel lines directly to the hose barb fittings.  I then safety wired the fire sleeve to the fuel lines.   Here is a pic showing the revised fuel lines in the firewall area.

ADDENDUM 2:

After further investigation and, yes deliberation, I ended up sealing the ends of all of the fuel line firesleeve with RTK high temperature silicone.  Ed at Rans had a great tip to use Formula 409 on your fingers.  This allowed you to form the silicone without it sticking to your fingers.   I've got these lines as fireproof as I'll ever get them now.

Lubrication System: Install Oil Lines

Since I purchased the kit in 2006, the Rotax engine has undergone some modifications which resulted in my needing to acquire updated oil lines. The ones used are pre-made by Rans with fire sleeve and all needed fittings. Here are lines connected to the oil cooler.

This pic shows the oil return line to the bottle, which has a banjo bolt connection.

This pic shows the line running from the bottom of the engine to the oil bottle. A very tight fit was encountered. Soapy water helped lubricate the line.

Here are two connections made at the oil bottle.  The black line is an overflow line. The angled fitting at the top of the bottle runs to the bottom of the engine.

Next pic shows the line running from the oil bottle to the oil cooler. If I recall, the straight bottle fitting at this location has a drop tube that expels oil to the cooler.

Next pic shows the line running from the oil cooler to the oil pump on the front of the engine.

Here is a closeup of the 90 degree fitting fastened to the oil pump.

Originally, just a threaded plug was located on the bottom of the oil bottle for oil changes.  I decided to install a quick drain valve at this location for ease of oil changes.  I zip tied the cabin heat hose away from the valve.  Not shown safety wiring to the engine mount.

Carb Heat Install

Beginning with the control cable installation, cable is threaded through two cable housings (conduit). The ends of the cable housings are wired to cable ferrules which bolt to the firewall (shown) and carb heat valves.

The two throttle cables daylight through the firewall and attach to a mixer plate. A control cable and knob ties to the other end of the mixer plate. The cylindrical aluminum piece with side screw is a control cable friction adjustment.

Here is the carb heat diverter valve unit. The spring keeps the valve in the "normal" position, drawing ambient air in through the air filter intake. To actuate the carb heat, you pull the knob and the valve switches to allowing warmed air from the muffler.

Next pic shows one of the heat exchangers bolted to each end of the muffler. The OD of the exchanger is larger than the OD of the muffler which allows air to be drawn in and warmed as it moves up the hose to the carb heat diverter valve.

Following pics show construction of the diverter valves.

Last pic shows entire view of the air intake system mounted to the carb.

Cabin Heat Install

The air intake for the cabin heat is shown at the front of the engine. The heater hose runs from there over the engine and down to the muffler wrap flange (heat exchanger) fitting.

Here is a view of the cabin heat air diverter valve, heater hose attached to the fire wall, and control cable fastened with two hose clamps to the forward lower horizontal engine mount member. Trying to thread a bolt throught two spring clamps in a confined space by myself took me hours to fasten.
Here is a closeup of the air diverter valve and control cable installed to the muffler wrap. The down position expells the heated air down and pulling the knob out on the instrument panel directs heat up and into the cabin.

This pic shows the cable routing from the firewall.

Here is the control cable push-pull knob assembly, attached to the instrument panel.

Cooling System Install

The cooling system was final installed today. Here is the radiator.

The radiator is attached to the firewall at two locations and from the front with a rod which is clamped to the engine mount.

The radiator hose runs from the expansion tank, down into the left side of the radiator. You can also see 5" of hose slit and zipped tied to the main hose for anti-chafe protection from the engine mount. An 8" spring was inserted into the ID of the hose to prevent the hose from pinching at a severe bend.

Here is the hose coming in to the left side of the radiator.

The second hose runs from the water pump down into the right side of the radiator. Again, a spring was inserted and extra hose was used for anti-chafe.

Here is a view looking up from the belly.

Not shown is a 24" piece of 1/2" poly tubing running from the expansion bottle to the overflow bottle mounted on the firewall.

Lubrication System: Oil Cooler Install

The oil cooler is mounted to the front of the engine. Here is a front view of the mounted cooler.

From behind, you can see it mounted to the engine in two of the three locations. The cooler is mounted between two aluminum channels/layers of silicone and sandwiched by four threaded rods. The silicone will dampen vibration.

You can see a gap between the cooler and vertical side of the channel. There could be concern that this will shift and rub metal on metal. Liquid silicone was suggested, but I don't want to risk plugging the cooling area. I will monitor through course of operation, as it eems like it is in there tight.

My kit is missing some oil lines (manual says to be provided by Rotax) so will contact factory to obtain entire updated lines sheathed with fire resistant material.