Hard to start when engine is hot

[Titanium Cranium]

I know that many planes don't like to start once the engine is hot after running, and I've found my Aerovee engine to be stubborn too, but more so than any other plane I've flown. After a flight of just over 2 hours, I landed, refueled, and gave it about 30 minutes to cool off before I tried to start up to continue my flight. After two failed attempts to start it, I gave it another 15-20 minutes to cool off, then tried 4 more times to start with no luck. After waiting another 15 minutes, I tried to start it a few times again with no luck. The battery was starting to get noticeably weaker. Luckily, a gentleman was at the FBO who let me hook up to his battery charger. After charging for about 30 minutes, it fired up on the 2nd try. The next day it had no trouble at all starting right up when the engine wasn't warmed up.

Do any of you have difficulty starting your aerovee engines when they're hot, and if so, have any of you found a remedy or something that can prevent having to take 1 1/2 or more hours at each stop on a trip?

[kmacht]

Has something similar once on the way out to Oshkosh. Landed to refuel and couldn't get it to restart. I ended up pulling the mixture almost all the way lean and was able to get it to catch. After it caught I went back rich and it started normally. I don't know why but it worked.

Keith
#554

[Titanium Cranium]

I may have to try that next time. I did try to lean the mixture a bit, but not a bunch. I don't usually just try to land, fuel, and go, but I'm expecting to fly from Dayton to Phoenix next summer, and I really don't want to add 7 hours just for extra time at refueling stops to cool off. I want to make sure I can stop, stretch my legs, hit the restroom, refuel, and continue on.

[mike.smith]

Happened all the time until I insulated my fuel line from firewall to carb. Then, never, ever again.

[MichaelFarley56]

Tom,

I've had the same basic issue and for me the answer was just what Keith described. On a hot start, I will leave the mixture at idle cutoff, make sure the fuel valve is open and throttle cracked, ignitions ON, and then I'll hit the starter button with the mixture still at idle cutoff. Normally the engine will catch for a moment and at the same time I'll push the mixture forward which gives me a smooth idle. If you've flown a fuel injected engine, it sort of behaves like that.

If it doesn't catch, then do everything above but leave the mixture at idle cutoff until it fires up; at that point you can then push the mixture in.

Let us know if that helps once you try it! I'm thrilled to hear you're having fun flying the Waiex. How's she doing for you? I hope to run into you around central Ohio soon!

[Titanium Cranium]

I'm pretty sure Don insulated the fuel line because it has what appears to be an insulator around the lines all the way to the aeroinjector. I'll give the lean mixture a shot. I'm loving the Waiex Mike. I've already put 27+ hours on it, so it's parked so I can do the first oil change, valve adjustment, and prop torque since I bought it. I actually wondered if you were near where I flew on July 1st, because I flew north of Columbus on my way out to Amish country. I also flew to the Appalachian Mountains on Sunday to see how the plane performed at higher altitude landings and take-offs (I was stuck at KBLF when it wouldn't start). I even got to do a little formation flying with my buddy's Christen Eagle the other day and got some air-to-air photos of both our planes. I've really been flying every chance I get and I'm loving this plane.

[kmwoody]

I also had the hot start issue after I bought my Sonex. I pulled the mixture out approx. half way between full rich and taxi lean. Started every time.

Ken W
Sonex 959

[Sonex1462]

It happens to me all the time. I use the idle cut off method others have described. I have my fuel line insulated with a inline filter and no gascolator. The fuel line is straight and all down hill from the tank to the Aeroinjector.
My Sonex is based at Phoenix Goodyear airport. I don't fly in the hottest part of the summer but I do fly when it is in the 90s and low 100s.
It took me a few times to figure out this hot start method. But once I did it works every time (so far). I just treat it like a hot fuel injected engine.


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[MichaelFarley56]

My Sonex is based at Phoenix Goodyear airport. I don't fly in the hottest part of the summer but I do fly when it is in the 90s and low 100s.

I don't mean to change the subject, but just out of curiousity, what do your CHT's and oil temps run when it's that hot?

[Titanium Cranium]

I'm curious to know as well, especially because I expect to be flying out to Phoenix next year and will likely be dealing with 110+ degrees.