Update 03/31/22

So yesterday the first start was good but I noticed a strange "whop whop" sound.  Then I realized I hadn't clocked the prop correctly and the exhaust was reflecting off the blades.

The next engine start trashed the ring gear again.   This time the missing teeth were 180 degrees from the last time (cylinder 2 versus cylinder 1 TDC).  I'll disconnect the ECU and coil plugs and make sure the coil trigger wires are where they're supposed to be.

 I was looking at the starter and decided to call Sky-Tec after finding there was a FAQ about Superior ring gears and 149NL starter issues.   The tech advised there was a Textron SB 1447 B that specified a shim to lower the starter to improve the starter releasing from the ring gear.  He said that over the years, the tolerances and machining have improved and with the new ring gears and starters, the clearance decreased so may require a shim that can be made (or purchased).   He also said that a way to check the starter is to put it on the bench, run it and look for the shaft to wobble.  A few thousands was acceptable.  He advised to contact him directly rather than ACS for warranty work if it is needed.

I've ordered a few fuse blocks to relocate the power from the VPX for the primary ECU, fuel pump & top coil so they're running directly off the Essential Buss to eliminate the .2 voltage difference between the A and B computers.  I'll examine the grounding to eliminate any voltage potentials between the computer and coils.

The belt driven alternator field and output wires are in the same tubing as the heavy starter cable for about 3 feet so may be getting induction when heavy current is flowing to the starter.   There are a few inches on the cold side of the firewall where the Essential buss power parallels the starter cable too that I will reroute.

The starter relay suppression diode SB560 1536G tested okay.   The way these are installed suppresses the relay coil field when it collapses but seems there should be one across the starter motor contacts as well.

I'm found some connections had loosened.  One was the large negative battery connection to the starter contact and the starter positive had loosened some.   I started ohming out the trigger wires again, to be sure they were correct. and my old Amprobe voltmeter started reading erroneously.  Ugh.  I headed to the computer and found some of the EM5 documents have been updated.  I'm looking for the coil trigger wire pins which I think are 9 and 11.

  

Update 3/29/2022

 I'd emailed Ross at SDS about some things I was going to check and he replied back with the suggestion to remove the bottom spark plugs, leave the fuel off, remove power to the bottom spark plug coil and run the engine with the starter to check the timing.  

The results puzzled me so I asked a friend that used to build race engines take a look.   We determined the trigger wires were swapped causing 1 & 2, and 3 & 4 to fire at the wrong position.   It was easy to depin the white and white blue wires from the Weatherpak plug, swap them and test.   The timing was as expected now.  Reflecting on why they were transposed, goes back to an earlier run when the top coil wasn't firing and thought I'd transposed the wires and also misdocumented one of the pins.  Now I'm wondering if the original issue of the top coil not working was related to the panel switch or VPX programming.

A negative battery cable connection was a little loose at the firewall and tightened.   

During several early sessions running the starter with the new ring gear, noticed the bendix wasn't popping back.   After multiple sessions running the starter with the plugs out, the ring gear teeth (when new, have a rough finish) were getting more polished and the starter wasn't hanging up anymore.  

I'd also noted that the primary/top computer's voltage was 13.2 and the bottom was 13.4.   I'd like to move the power source for the top one off the VPX and to a breaker/switch feeding off the Essential Buss.  It may as well be there since the engine will not run without the Essential Buss.  My earlier thinking was that I could see the exact current draw, but it is so low, the VPX doesn't read it.

The alternator belt (Dayco 15350) is still in good shape but I was going to put a new one on.  It was really tight so put the original one back on.  I might try a 15360 belt next time.

Will do a short test run tomorrow when my friend and an IA will be here, then put the cowls back on.

Update 03/28/2022

 The test run yesterday was very short.  Immediately had a kick back and another munched ring gear.   Emailed details to Ross.

The domino effect was that little metal shards got into the prop bolt threads and I didn't realize this until I had about a half turn on most of the bolts and they got very hard to turn.   It took quite a bit of force to remove some of the bolts and the threads were very damaged.   I contacted Saber Mfg this morning and they had bolts and lugs in stock.  They're only about an hour away so I hopped on the bike with the extension in the saddle bag.  Met the owners grandson and an employee at their shop next to a grass strip.  They quickly replaced the lugs and provided new 6 1/2" bolts.  

I picked up a new ring gear at Aeroperfomance and a couple barbeque sandwiches nearby.  

Ross had replied with a list of things to check: Magnet position, top sensor connected to the top board, and the magnet position settings to 97 (top ECU) and 88 (bottom).  The crank retard value is also set to 25.   I mentioned to Ross that one thing I had done was set the mixture knob very rich since the previous start required increasing the mixture to get the engine to fire.

I checked the magnet positions and they seem to be as specified with regard to TDC.  Also checked the top sensor is connected to the top ECU, ECU settings were correct.  Powered the ECU up and waved a magnet by the sensor and the injectors click.  Sent an update to Ross to see if he has any ideas.  

Update 3/26/2022

 The Bosch AFR sensor has been replaced since cleaning it did not restore it's function.  With no power to the sensor heater, it would read 10, with engine warming up and heater powered on would momentarily read 13 and then go to 15 or higher.

The 2nd ring gear was replaced yesterday.   A Dremel cut off wheel cut a slit as deep as possible without nicking the flywheel, then a cold chisel was used to pop/crack the ring.  The replacement ring was heated to 450F and the flywheel was chilled in the freezer to prepare for installation.   The ring easily dropped into place and shrank in a matter of seconds.  A new alternator belt was installed.

LPS2 (no silicone) was used to lubricate control surface hinges.  

We'll plan the cowls on and do a taxi test on Sunday or Monday.  We'll plan on about 40 knots to finish bedding the brakes.

Update 03/21/2022

The SDS and got it installed into the radio stack last night.  It powered up and I stepped through the menu a little and saw it has changed a little.

I put the cowls on, pushed the plane back so it's rear was sticking out of the hangar but not blocking the taxiway.  Then, chocked the wheels, set the parking brake, turned on the master and engine buss switches, waited for the EFIS to boot up, and turned on the rest of the switches except for some reason, I left the back up ECU off.

The throttle was cracked a little and as the engine cranked, I rotated the mixture knob richer and the engine fired up.  I moved the mixture back to center as the engine warmed up.   Then I noticed I hadn't powered up the back up ECU on so turned it on and the RPM picked up.  I switched the top and bottom coils on and off and found the #2 cylinder was missing.  The EGT for #2 was higher than the other cylinders.   Increasing the throttle and leaning didn't clear the fouled plug so I shut down, pulled the bottom cowl, removed the plug and sprayed it with carb cleaner.  I started the engine back up but #2 bottom plug still wasn't firing, so shut down and swapped it with #4 after shooting it again with carb cleaner and scraping the insulator.

The next run was better but apparently the plug has a carbon film on the electrode and isn't firing as hot as the other plugs.   I had to close up the hangar due to severe weather in the area.   I'll order some new plugs but will try another run tomorrow.

The AFR sensor doesn't seem to be operating properly.  With the heater/power off, reads about 10:1.  When the power is turned on , it reads around 13 for a few seconds and then jumps to 15 and as high as 17.  Rotating the mixture knob doesn't seem to affect it.

Vance Atkinson and Jerry Schneider are allegedly going to stop by in the afternoon!  I'm not worthy!  :-)

Update 03/19/22

 I received the SDS EMF5 ECU back after a software upgrade.  I also upgraded from the round programmer to the rectangular programmer.

The ECU is re-installed.  The programmer will need a faceplate or some method to install it into the radio stack.

I'm hoping to get the cowl back on and another test run today.   Hopefully the kick back issue is resolved.

First Flight Guidance

Advisory Circular 09-89A: AMATEUR-BUILT AIRCRAFT AND ULTRALIGHT

FLIGHT TESTING HANDBOOK

 https://www.faa.gov/documentlibrary/media/advisory_circular/ac%2090-89a.pdf

First Flight In Your Homebuilt Aircraft -- FAASTeam - Safety Video Archive - Unofficial Video:

First Flight In Your Homebuilt Aircraft

FAA inspection complete

 Airworthiness inspection was completed today!   I'll post more later....