Check this if you have an injected engine...

[Caveman]

Originally Posted by jeffw@sc47

Where do I find the Operating Limitations that are pertinent to my build, airframe, engine, other systems?

Try here:

https://www.faa.gov/licenses_certifi...craft_records/

Joe

[douglassmt]

I read this with interest because the same thing happened to me. I helped a friend finish his RV-7, including getting it painted (by someone else), final assembly, panel design and procurement, installation of panel and associated wiring, flight test prep and most of the Phase I flight testing. I did the requisite fuel flow testing to ensure that the boost pump was making 150% of takeoff fuel flow but I did NOT pressure test the fuel system with the throttle and mixture open and closed.

First flights were noneventful except for some funky CHTs and EGTs. As I recall, EGTs on one side of the engine were higher, indicating that side was running leaner than the other. Long story short, in looking at possible causes we noticed some blue dye residue around the spider on top of the engine. It was a very small amount. I didn't even notice that fitting on the spider, which did not have a red cap on it, although in looking at photos from before the flights it had a red plastic cap on it before the first flight. Figuring there might be a fuel leak I pressurized the fuel system with the boost pump and...PSSSSt, a constant stream of fuel shot out of that fitting, which is one of those pressure dampening fittings. Yikes.

In retrospect, I had noticed a VERY slight fuel odor during first flights but so slight as to be intermittent and not all that unusual around an airplane. I realize this could have ended badly and could have been prevented by simply looking for ANY fuel leak like I should have by pressurizing the system. After removing the fitting and plugging it with a solid plug, the EGTs and CHTs evened out.

I speculate that the only reason I didn't get a fire was that the pressure reducing fitting limited the amount of fuel and the fuel/air ratio was too lean to burn. Pretty narrow margin of safety and unlikely to have continued under all phases of flight. I found the leak while still during engine break in, running max power and full rich during all phases except landing and taxi. It may not have produced any fuel during taxi but I can't say for sure.

I wondered why this fitting was even left on this engine, which came from Van's. In my opinion they should be noted or better yet, removed. Still, the fault was mine and everyone should be aware of it.

Side note: this fitting was NOT present on my RV-10 engine that I bought from Aerosport Power.