I've definitely decided to not do the fuel injection add-on at this time.  It's just not worth the disruption to finishing the plane.  I'll revisit it after it's been flying for awhile.

Meanwhile, I also decided to do the fuel flow measurement exactly like the factory does it (as described in the manual).  Basically, cutting in the FT-60 sensor into the fuel line to the right carb.

To do that requires some material and tool purchases...  I asked the factory what silver "solder" they use (it's actually brazing, not soldering) and they said any is fine as long as it's flux-coated.  I don't think that's necessary as long as you use flux (you must with silver soldering), but I did find a top quality flux-coated silver solder to use.

After LOTS of research, here are all the materials and tools I got:

Silver Solder (High silver content makes for a super strong bond).
Torch Nozzle
Torch Gas (Propane is not hot enough for this purpose)
Welding Blanket (you definitely want to protect the engine under the fuel line you're brazing)

Here's info on the silver solder from the manufacturer.  The "Guide" under the Resources tab is useful reading on how to use it.

I'm not coming into this completely as a novice.  I took a "Sculpture and Welding" class way back in college, so I'm fairly comfortable making hot flames. :-)  Maybe after the plane is done I'll start making sculptures again with my new tools. :-D

Another instructional guide on using silver solder (it's oriented toward jewelry, but still useful).

1 hr. on the fuel pumps.

Got my replacement manifold.  Can you tell which is the new and better fabricated one... 😎

After a half an hour of physically taxing twisting, plying, pulling and pushing, the new manifold is on...  I'll test it tomorrow.

Thanks, PeterC, for the idea to flip one of the pump mounts so it would be easier to put the clamps through.

Test fixture pretty much ready to go.

1 hr. on some fuel line fittings and ordering a missing part.

Got the two oil tank fittings today and they fit perfectly.  Whew...

Finally getting around to putting in the two 1/8" to 6mm barbed fittings for the returns from the switch to the tanks.  Loctite 577 applied...

Finger tight plus a minimum of 1.5 turns around.  The Gearwrench is very useful for this.

I don't have any stock of 1/4" to 6mm barbed fittings, so I ordered those from here.  I got 4 aluminum and 4 brass since I noted that the ones you cut and silver solder on are indicated as brass.

No direct work on the plane today (it's my anniversary, so it wouldn't have gone over well...😎).

But, I've been working on the more detailed engine build task list and I'm hoping to post that tomorrow night.

I did consolidate the firewall and engine factory photos pages to just the one engine page.  I also added a bunch of photos that I got recently that are very helpful, showing various engine close-ups.

Still undecided about the EFI addon.... 50/50 in my head at the moment...

I'm planning to install the 914 fuel injection addon from Edge Performance and am considering doing it now versus doing it later (my original plan).  Doing it now would certainly save me work since I haven't done all the fuel/oil/coolant/electrical work yet and that would largely have to be redone.

Here's the installation manual, which I think is very well done.

Doing this means not using the current TCU (and its harness...) and not using the current fuel pumps as it comes with high pressure pumps (which look already assembled...).  Of course the carbs are gone and they recommend using a intercooler which they say may involved a bit of work to figure out how to install it.

Using their control unit and the intercooler and I'd see 125 HP (vs. 115 with the stock 914) with better fuel economy.

I'm interested in your thoughts on this!  I'm leaning toward doing it now, but still not a slam dunk in my mind since it would delay the completion.  I'm guessing it would mean a 2-ish month delay.

1 hr. on the oil thermostat and misc. contemplation...

You might have seen that someone commented on my last post about identifying the connections from the TCU.  They said that the wires have numbers on them and that they correspond to....

... this diagram in the Rotax manual (the numbers match the pin numbers on the wide connector shown on the right bottom).  I'm an electrical engineer and I find this diagram annoying to read.  It could have been made to be far easier to parse for readability and usefulness.

The numbers on the various blocks are identified on the previous page.

Based on a picture from the factory, this will go here with the fittings oriented as shown.

Fortunately I had a socket large enough to fit over the NPT adapters which go into the oil thermostat.

My wrench ready to go and the photo from the factory.  The fittings show about 4 threads.

The manual doesn't mention it, but these being NPT threads, you should put Loctite 577 on the threads.

Wrenching them down.  Getting it down to about 4 threads showing required a lot of force - and there's no way I'd go further.  Be careful when you're putting the socket over the fittings as you really don't want to nick or scratch the flares.  I also couldn't get the socket over the barbed fitting because it was too long, so I used an adjustable wrench and tightened it from the side.

Excess 577 wiped away and comparing it to the photo.  That'll do.  Very tight...

I was told (by CA, not technical support in SA) that HW-FTG-703-X-X is the part for the two 90 degree fittings for the oil tank, and I have two (or more) empty bags with that number.  But, I think those are the 90 deg fittings attached to the oil thermostat and not what goes on the oil tank.  Checking with the factory on that.  Meanwhile, I was told on Rotax-Owners.com that this part should work on the oil tank.  Checking with the factory on that too.

Meanwhile, I feel like I'm flailing with regards to the engine install...  Too many open issues, a couple of missing parts and no definitive task list are the reasons.  I need to remedy that by starting with a detailed task list.

Pretty impressive numbers!!

Read more here.

If you've never been, you owe it to yourself to go at least once!  Go next year, when I'll be flying my Sling 4 there! :-D