Fuel Pump Cover & Hangar Space

1.0 Hours

Since I have run the engine a fair amount and see no more fuel leaks I decided to put the fuel pump cover/shield in place. See below. I had left it off to watch for any leaks since there are so many connections in the pump assembly. The lower cowing was in place when I tackled the job and I really should have taken the lower off but it is kind of a headache getting it back on after so thought I would give it a go the way it was. Man what a pain that was. The motor mount is right in the way of the left side screws. Especially the middle one. After I had proven the fuel pumps were not leaking I should have put the cover in place when I last had the lower off as it was a difficult task. I got it done after quite a bit of time and grumbling on my part.

I have not been able to work on the plane as much due to lots of family activity but also because I am running out of things to do (that is until I get it to the airport and commence with final assembly). Where I have been spending time is trying to find hangar space at the airport I want to base out of (KLWM). It is like you have to know the secret handshake or something…. Friday afternoon I went over to speak to an FBO owner who I had missed on other occasions and had a good conversation. He shared that he had nothing available but he did have a customer that is a snowbird that leaves around 10/1 for Florida and is gone six months. He said he would talk to the owner and see if he will rent it to me for that period. He said he would let me know the situation this week. Fingers crossed. While it does not solve my issue long term it would allow me to continue with the process and I would become immersed in the community which should help find a more permanent solution.

I went up to see my #1 plane helper at her College today. I could have used her small hands putting the fuel pump cover on!! The house is now empty and I hate it…….

Fuel Pressure & Rocket Motor

4.0 Hours

I received the new fitting for the air-box that will allow me to connect the fuel pressure sensor directly to the air-box as I alluded to last update, so went ahead with the move.

I then connected teh 1/4″ hose to the fitting. I really do not like the way the hose has to bend to get on the fitting. I have seen where other installs use a 90 degree elbow but that would mean taking the other fitting right next to it out as the elbow would not be able to turn as they are too close together. I will look for an appropriate fitting but for now I want to see if the move to the air-box location corrects the fuel pressure reading.

Yesterday I pulled the plane out and ran it and…………………….. Fuel pressure sat at 3.6 psi while running. Perfect !!! Check off another issue.

On to installing the rocket motor. I will say I did this with some trepidation. In the below pic you can see I am holding the rocket in front of the steel cage that it ships in. Pretty serious stuff.

Below is another pic of the rocket as well as you can see the parts that it comes with on the bench to the left of the rocket. Note the pink tubing as I will talk about that in a moment.

Below I have removed the steel trigger guard and installed the cables that will pull the parachute out. Note you re-use the screws that held the trigger guard on.

I VERY carefully slid the rocket into the receiver as I did not want to strike the trigger accidentally. Note how high the rocket sits above the receiver. The directions do not show that so emailed Sling in South Africa to make sure all was good. They said that was accurate.

Above I pointed out the piece of pink tubing on the bench. You use it to create a seal between the rocket and the receiver. As the tubing is rather thick you need to heat it with a heat gun then wrap it around a screw driver to flatten it out some. You use a screw driver to get it started and then tap it in. I just used a piece of wood and a mallet. I highlighted where it sits in the below pic.

Lastly I attached the Bowden cable to the rocket. Again I was ver careful as the trigger is exposed. The instructions say to keep a hand on the trigger at all times while going through the process. I guess I did it right as it did not go off. The last step I have to take is to add some safety wire which I will do today.

Parachute Install (part 2), Float check & Fuel Pressure Sensor Plumbing

4.0 Hours

I took my time and did a better job coiling the smaller steel parachute cables so that they lay in the cable tray better. You absolutely have to use cable ties to secure it as you are doing it.

And here it is with the parachute in place and connected

One thing to note is that you need to zip tie the parachute bag to the one wall with all the holes. See a prior pic to see all of the holes that are used. You are supposed to run the zip ties from the outside. Makes sense otherwise how are you supposed to tighten them up? Unfortunately I had already put carpeting on the interior so I had to install the zip ties from inside the box. It was a pain as they get sandwiched between the parachute bag and the wall. It was difficult and time consuming but think it is now good. You have to do this or I could see the parachute bouncing up and down in the box. Also the parachute bag is much smaller than the box so I was toying with adding a piece of styrofoam to use up some of the extra space. I am sure that is questionable so will reach out to the factory. Even with that piece of styrofoam it is still very loose. The rocket install would be the next to last step but have to say that it makes me nervous. When I was in Torrance in June Jean shared a story where one went off by accident at the factory and blew through a wall.

Next up it was time to tackle Rotax Service Bulletin 914-056 which is the checking of the carb floats and replacing them if necessary. I had reached out to Peter Calley as he was in the middle of doing it as well. I wanted to see if he had any issues doing it with the carbs remaining in place. He said it was not an issue which I was thankful for as I had just balanced the carbs. You do need to get the drip tray out of the way. See below.

Cut the safety wire and a 19mm wrench will get the bowl off. Remember the bowl will be full of fuel if you have run it and it will leak quite a bit of fuel when you remove the bolt. Get the rag in there. Below you can see the bowl with the floats. Note there is a little “varnish/goo” in the very bottom from when it was run in the factory.

The moment of truth. Are the floats labeled with an “R”? If not they need to be replaced. And the answer is……….

That is good news as a pair of floats is $150 and would need four. I have new bowl gaskets and “O” rings on the way. I guess technically I should not have to check the other carb but want to look in the bowl to see if there is anything going on with the floats as I want to see if there is an obvious reason for the engine running rich. I did clean up the bowl I have off as well as polished the pins the floats slide on

So the fuel pressure issue I was seeing when balancing the carbs is something I continue to research. I found that without the engine running the fuel pressure reads perfect but when it is running it reads high. It had me thinking that maybe I have the pressure sensor plumbed incorrectly. It is a differential sensor so one side goes to the fuel line and the other side goes to measure manifold pressure. Below is how I had plumbed it. Notice I had tied into the manifold crossover tube that the manifold pressure sensor utilizes. See red box below.

I called Lockwood Aviation and spoke to Phil Lockwood and he shared that they do not go there. They leverage the extra port on the air box. That is interesting. While I am not positive that will address the issue I am going to make the change. I started taking it apart but will have to wait on a fitting to complete the switch.

Air Box Port

Parachute Install (Part 1)

2.0 Hours

I decided even though I did not want to add weight to the plane before the move to the airport the concern was over shadowed by wanting to get as much done before I leave. I broke out the parachute itself and started getting acquainted with the parts and the process. I will say the Sling 4 manual is light on instructions so I went to the TSi fuselage manual and was pleased with what I found there. Below is a pic of the parachute and the shackle that is used to secure the parachute to the steel cables from the plane. The shackle is really impressive.

The first thing the manual says to do is cut some 5/8″ heavy wall tubing and install it in the bottom of the parachute box. The manual says is to keep the parachute from sitting in water if some should get in. I thought that made pretty good sense. You rivet them down.

As I had already added foam insulation to the bottom of the cable tray I proceeded to move to coiling the smaller longer cables and laid them in the tray. It says use zip ties to keep it all together.

I am going to have to classify my first attempt at coiling the cables as a fail. The heavier steel cables lays on top of the coiled cables which, the way I have it, would not let the skin that covers this up from laying against the fuselage. After looking over the pics in the manual I think they are much more precise with the process of coiling the cables. I will give it another go. There is a possibility that the foam I have in there is too thick as well. We shall see.

Compression, Fuel Flow, and Wiring

5.0 Hours

My understanding is that during the airworthiness inspection the DAR will want to see compression results even if it is a brand new engine. With that in mind I started preparing the engine to do so. Below is the ignition modules and the two connectors that are utilized to remove spark from the system. I took those apart to ensure the engine would not start.

I had my son in the pilot seat cranking the engine while I was outside taking readings. I pulled the top plug of each cylinder to make it easier to spin the engine.

I added the readings (135, 132, 132, 128) to the logs. One thing that caught my attention when I pulled the plugs was that it was obvious things were running rich. Below is the #1 cylinder plug. The engine has only been run .4 hours so they should not look like that. I will talk more about that further down.

The second task was to verify how many gallons an hour the fuel pumps were delivering. I had two plastic jugs, one of which had a mark for a gallon. We got out the stopwatch and timed how long it took to deliver a gallon via the return line. Below Wes is timing the event.

This was done without the engine running though I did have the battery charger/maintainer attached. I actually leave it on all the time. For the main pump I got a flow rate of 31 gallons/hour. For the Aux I got 27.5 gallons/hour and with both running I got 33.0 gallons/hour. Considering max draw is about 9.0 gallons an hour for the 914 I think we are in very good shape. All that returning fuel will certainly help with vapor lock too. I added those numbers to the logs as well.

So the rich running engine….. I noticed that when I was syncing the carbs the fuel pressure was reading 6.5 psi. That is well above the max listed in the operating manual (5.3 psi). It says that if the pressure goes above max it can push fuel past the floats. Hmm, could that be causing the richness?? When I was performing the fuel flow test (engine not running) I noticed the fuel pressure was perfect (3.7 psi). Hmmm, wha tis going on. I need to continue to trouble shoot that.

I got some small things done as well. I installed the fire extinguisher below the pilots left knee. I found it did not interfere with my leg at all. I riveted the bracket in place with 4.8mm rivets. I needed to make sure the rivet went through the upholstered panel as well as the aluminum skin underneath.

I had a couple minutes so I created some labels to put on the spats that indicate what the air pressure should be.

The last thing I did was try to figure out the wing wiring as I needed to install the connector on the wing side. These wires are for the strobes, the landing and taxi lights and for the port wing the pitot heat. At the wing root there was numerous white wires. The strobes have four colored wires so those were easy but the landing, taxi and pitot wires were the same though I did have one wire labeled “taxi” which I did a couple years ago. Long story short, that labeled wire was incorrect so it took a while using an ohm meter to figure it all out. I got out my label maker and labeled each wire. I then pinned the wires and installed the connector. At this point I should be good to go with just plugging each wing’s connector in to the matching connector at the fuselage. Famous last words….

I will say that working through the various squawks has been a learning experience.

Balancing Carburetors

5.0 Hours

I was able to spend most of the day in the “Hangar” working on balancing the carbs. What a learning experience it was !! A couple of missteps that prolonged the exercise as well as a part failure that I will share in hopes that it helps someone else doing this for the first time. Below is a pic of the tool I purchased last year when I took the Rotax class down at Lockwood Aviation in Sebring FL. It measures vacuum and is installed where the crossover tube meets one of the two intake manifolds. You disconnect one side of the crossover tube and put one vacuum hose on the end of the crossover tube and the other on the manifold where the crossover tube attaches. One gauge per manifold/carb. I think it is called a manometer.

What you are doing is setting the idle speed and balancing the carburetors at the same time. You warm the engine up to a minimum of 120 degrees and see what the RPM’s are at when the throttle is pulled all the way back. You then bring the RPM’s up to 2,500 and see what the two gauges read for vacuum. Below is a pic of me checking the gauges while the engine is running.

To adjust you make the appropriate changes to the throttle cables. I had started and stopped the engine numerous time making adjustments. By the way you can really tell when the carbs are not balanced as the engine runs rough. Then I thought what was going to be a huge setback occurred. The ferrule at the end of the throttle cable on the right side broke. I could not believe it as I was definitely NOT putting much pressure on the nuts. Just snugging them up.

All sorts of thoughts of having to order a new cable and waiting months went through my mind. I remembered I had a couple of those ferrules left over as I ordered them for the heater cable. The problem was the one on the throttle cable had a slight crimp on it. Using a couple of plyers I was gently able turn the ferrule and once that occurred I was able to pull he old one off the cable.

Below is a new one.

I dd not have anything that would put a crimp on it so thought I would use some shrink wrap to hold the cable to the ferrule. Also, because the carbs are sprung to go to full throttle if there should be a cable break it is always pulling the cable and cable housing forward into the bracket which I think minimizes a concern.

I secured the cable back to the carb and basically started the process over. Now here is a big lesson learned that I want to share. Do not forget about the prop !!! I had forgotten about checking it and found the last time I messed with it I had left it set to manual and it was adjusted to coarse pitch which of course affects RPM’s. When I moved it to fine pitch for takeoff the RPM’s jumped by 400 RPM. Ugh. Back to square one. When I began that process the ferrule on the side that did not break, broke. What is going on??? Before it broke I was able to compare the two ferrules when I was adjusting the cables and the new ones were much firmer when tightened. The old ones are soft and pretty thin-walled. I am sure people will think I was just too heavy-handed and I am convinced I was not. I have been doing maintenance on all of my equipment/cars since I was very young and believe I have a good feel for tightening nuts and bolts. I had another ferrule so started the replacement process again though this one seems to be on the cable housing much more securely. I had had enough so thought I will come back at it again tomorrow. Below is the second one that broke.

Overall I learned a ton of how to work through the process and once I get the cable fixed think it will be a much quicker process to get them balanced and the idle RPM’s set at about 1,800. I am actually happy the parts broke now as I would not want to deal with that when I am actively flying. While it would not have stopped the engine it would have been something that would have had to be dealt with quickly so N77RL was not out of commission.

Fuel Pressure Reading

4.0 Hours

It has been difficult finding time to work on the plane but managed to sneak in a few hours over several days.

First the fix for the RPM’s worked. Check

The fix for the fuel pressure reading on the G3x did not work. I spoke with Midwest Panels and under their guidance went back and looked at the same GEA connector that had the broken wire for the RPM issue. According to what I was given as an order for pins 1, 2 & 3 the colored wires were not in the correct sequence. Using the de-pinning tool I pulled the pins out of the d-sub connector and put them back in the order I was given.

After putting it all back together tonight I put the fuel lines hanging out the side of the fuselage in a tub of gas, turned on the avionics and flipped the fuel pump on. I have a fuel pressure reading !!! Another squawk fixed.

Next I pulled the Artex 345 ELT out from under the back seat and got the 15 digit Hex ID off the unit. That is what you need to register the ELT with NOAA. It was a simple process. They mailed me a confirmation

Next I wired in a connector for the wing tip strobe/NAV lights for the starboard wing thought I need to look at how I connected the landing /taxi lights so I connect them in the proper sequence. Note that if you have a quick build kit the wire the factory drops in the wing for the wing tip lights has six wires in the bundle. I have AVEO lights and they only require four wired of the six provided, In my case I did not use the green and white wires.

My fire extinguisher came in this week. Got it from Aircraft Spruce. I put my hand next to it so you can gauge the size. Need to figure out where to mount it.

Now that I have what I think are all the engine squawks addressed I am going to balance the carbs next. Looking forward to that exercise !!

Fuel Pressure Sensor & RPM’s

3.0 Hours

Made some progress on the two issues I am having with instrumentation: Fuel pressure and RPM’s not registering on the G3x. Spoke with Steve at Midwest Panels on both and discussed what I needed to look into. For the fuel pressure issue first thing was to see if they gave me the correct sensor. It was correct.

Next was to look and see if I connected the three wires from the sensor to the correct wires on the harness. I have run all the engine wires through two connectors to make it easy to remove the engine in the future so had to get access to those and look at each side of the connector to check the wire alignment.

I had connected white > white, orange > orange and blue > blue. Seemed logical to me. Wrong. I left the sequence at the hangar but there is no logic to the sequence, you just have to know it. Grrrr. Steve gave me the sequence so I de-pinned the three wires on the female side of the connector and re-installed them so they match the proper wire on the male side. That should do it.

On to the RPM issue. I was directed to look at the connector that attaches to the GEA 24 unit. I took the right side G3x display out to get access to it. I slowly took the connector apart.

Once I got the main plate off the connector the issue quickly presented itself. One of the two wires for RPM’s was broken off at the pin. I know it is a blurry pic but see below.

If you recall Midwest panels had sent me a replacement wire from the TCU with the resistor and diode built into it. Taking the connector apart revealed the diodes were inside the connector which I was not aware of. Basically what I have now is one set of resistors/diodes following another. No good. Steve is sending me new wires with the pins installed. I do not have a crimper to install D-Sub pins and am not interested in spending the money to get one. The good ones are expensive. I did order a de-pinning tool from Steinair.com (short money) as I need to remove both pins then cut out the original wire and solder the new wire Steve is sending me to the replacement wire I had installed from the TCU a couple weeks ago.

I have to believe both fixes will work as I saw the issue with both problems and see how the moves made/being made will resolve them. Unfortunately this will not be done until later next week and I cannot test the fuel pressure reading until I get the RPM fix as the fuel pressure wires go through the same connector which I have off at the moment.

Door Seals (Continued)

8.0 Hours

Good weekend at the hanger with some success and some fails as well. In the last update I shared that I was doubling up on the draft seal and the “D” shaped rubber weather stripping because that is what they do at the build assist center. What a failure that was and it is my fault for not trusting my instincts and realizing the TSi canopy is different than the Sling 4 canopy. The two layers were way to thick to allow the door to come close to closing. Thank goodness the glue I was using that the build assist center used did not do a good job of adhering to the weather stripping and we were able to pull the “D” rubber back off easily with no damage to it but the thin draft seal was a total pain. My daughter and I spent a couple hours getting it off as well as getting the glue up. Below is after we cleaned off the seal with lots of elbow grease. We had lined the area with tape to prevent glue from getting everywhere.

Below is a pic of the “D” weatherstripping that I applied directly to the channel in the canopy.

As I was not happy with the glue we used the first time I went back to the tried and true contact cement I have used on several things during the build. It is shoe glue called Barge. Below you see Sabrina putting it on the weather stripping. The stuff is really toxic so whenever it is being used we use a respirator.

And now to the canopy…..

As I expected it worked well. Both sides done and secure.

So even with just the “D” weather stripping the doors are still held off the canopy frame so had to continue to work the door latch “Hooks” to allow the doors to lock closed. If I had to do it over again I would put the weather stripping on first then drill for the studs the hooks engage with. I spent a fair amount of time grinding the hooks down some more to allow them to fully engage. They do engage but are snug which I think is a good thing as it should prevent leaks. We shall see….

The other thing that bugged me about the canopy is the head of the bolt that holds the piston to the door hits the canopy edge and digs a trench in it. See below. While I was in Torrance I looked at two Sling 4’s they had there and both had the issue.

There is a washer on the head side of the bolt that I thought I would try removing and see if it helped in spite of the build manual calling for it. I also noticed that the two Sling 4’s in Torrance had the washers removed.

I removed it and while I don’t think it is very good to not have a washer there it eliminated the conflict.

I got to do a few miscellaneous things over teh weekend besides the doors. I put the data plate on…

I also installed the interior pouches on each side of the fuselage. I was trying to think about how to install a rivnut through multiple layers of material and decided to give up on that idea and just riveted them on.

Sabrina and I also tested out the radios and intercom again.

The real downer this weekend was the fix for the RPM display on the G3x did not work. The fuel pressure is not working either. I will talk with Steve and Adam this week to see how to figure it out.

Getting Current & Door Seals

1.0 Hour

I have not done much on the plane in the last couple weeks because I had another large aviation task to tackle. I needed to pass a bi-annual flight review which would not be very difficult for pilots that have continued to fly. I am in the unenviable situation of not having been PIC in 28 years (pre wife and four kids). As the plane gets closer to completion I needed to tackle this task which was daunting to me as it has been so long. I purchased the Sporty’s Private Pilot course and poured over that information before signing up with a local flight school. Then something interesting happened before I got started which was a conversation with Jean at Sling in Torrance, CA. I off hand said I needed to get current as I am getting close to moving to the airport with N77RL and he said “Why don’t you come out here to the Sling Academy and get current here”. It only took a minute of thought to realize the benefits of getting current in a Sling which also has the same avionics as me (Garmin). It will also help with insurance requirements. That is how I ended up in Torrance, CA all of last week for a very intense week of flying and ground school with my instructor. In six days I got in 15 hours of flying and a whole bunch more 1-1 testing of rules and regs. I will say I was B-A-D the first several flights but then things started clicking and Saturday I received my sign off. What a wonderful feeling of accomplishment. It has been a very long time since I felt that way. I realize I have a ton more learning to do but I view it as a significant step forward. I flew the Sling 2’s they had the first half of the week then the TSi the last half. I have to say I really enjoyed flying the TSi. It is heavier (like the 4) and as a result felt more stable. Obviously the power was superb with the 915. I think my right leg is now quite a bit stronger as you have to stand on right rudder, and I mean STAND, on climb out in order to maintain coordinated flight. I would be at pattern altitude by the end of crosswind at the latest. Impressive. Below is the old man (me) with the TSi…

While I was there I got to visit with Jim Pavlick and see his Sling 4 which is in the process of getting painted. What a beautiful machine Jim.

Headset Evaluation

While I was out at the Sling Academy I was able to test out a couple of headsets that I purchased at Sporty’s. My thought was to try them out and return the one that was not the favorite. I brought with me the David Clark DC One-X and the basic Clarity Aloft unit. The Clarity Aloft unit is certainly different than anything I have worn before.

Comfort and noise control was the primary factor but also clarity (both receiving and transmitting). The winner ended up being the Clarity Aloft unit with the primary factor being comfort. It was so much cooler and more comfortable to wear than the typical muff headset. I am not saying the DC was not good. I think it was very good but the muff style could not compete with the two ounce unit from CA. I knew it was good fit for me when I did not even think about the headset while I was flying.

While I was in Torrance I also visited the build assist hangars (Sling has two) in order to ask numerous questions. I was not clear on how the door seals work as there are two parts. There is a flat piece of rubber call “Seal Draft” then there is the “D” shaped rubber seals. The guys in the assist center shared they always put the flat Seal Draft down first then go over the top of it with the rubber “D” seal. Below is how they lay together. They indicated the approach ensures there is a good tight fit between the door and the rubber. The flat Seal Draft has adhesive already on it (see the second pic below). Peel and stick. I did use some alcohol on the canopy first. The “D” rubber has to be attached to the Seal Draft with glue. The build assist guys shared what they use which I will share with you when I receive it and glue it up.

I am now very motivated to get get this thing done !!!!