AeroVee - starting and running issues

[Rynoth]

Crikey, Ryan, that's a lot of gunk. When I have bought hose from car parts shops it is specifically labelled for "FUEL" or "OIL", implying different materials for the different fluids and not interchangeable.

Peter

I'm still trying to verify the source of my fuel hose as a precaution, but to your point, I've only ever seen a hose rated for gasoline to also work with oil. Case in point: https://www.summitracing.com/parts/sum-230620

"Even better, our hose is designed to handle gasoline, oil, or coolant."

Coolant hose however is usually not good for oil or fuel.

[sonex1374]

I've seen this same thing on my airplane one time caused by 100LL evaporation. I left the fuel shutoff valve cracked just a bit on after shutdown one time and there was a slow drip out of the carb for a couple days. The fuel dripped onto the lower cowl and evaporated, leaving a blue waxy layer as the the fuel slowly ran down the cowl. It seems to be something in the fuel that is only noticeable after letting a bunch evaporate.

I've had similar problems with certain brands of auto fuel as well. Shell and BP were (still are) the worst. You can easily see this for yourself by poring a small amount of gas onto a clean white paper towel. If it leaves a discolored ring on the towel, that's the additives in the gas that are left behind after evaporation. The same thing happens inside your carb where evaporation can occur. Nasty stuff for sure. I test all my auto fuel for these additives now, and stay away from any that leave a stain on the towel.

Jeff

[1X99]

Here's my (somewhat) related problem:
Turbo Onex, About 2 hr total time(good running), Secondary ignition set to 23° BTDC.
Last attempt (Jul '17) to takeoff resulted in a huge thrust loss just as the wheels lifted off. Throttle to idle, coasted to about 30 mph, prop stops, steered to the grass between the runway lights, managed to get it started and running with ~ ½" of throttle.
On return to hangar, #1 exhaust collector was only luke warm. #2--#4 hot enough to burn my calibrated finger.
Investigation:
All pushrods in place and clearance 0.006 & 0.008. Removed lower plugs, grounded them to case, turned on secondary ign., verified power to coils & Hall effect sensors. Cranked engine and found no spark at any of the 4 lower plugs. Checked secondary trigger magnet and found a lot of wear on the outside of the cap it's embedded in, and the cap had lots of clearance with the upper H.E.S but little to none with the lower. The magnet seemed to still be alive.
All ideas welcome!
Steve Craigle 1X99

[SonexN76ET]

Steve,

First even if your secondary ignition is not working you should still be getting spark from your primary on all four cylinders so you likely have something affecting the primary ignition system too or something preventing proper induction to the cold side cylinders.

On the secondary, the the trigger magnet should not touch either of the Hall effect sensors. You loosen the retaining screws on the Hall effect sensors and slide them back a hair so they don’t touch the trigger magnet. If they have touched with the engine running I would not count on the magnet to still be reliable. You may also want to look into the service bulletin warning about the need to use larger screws and Loktite primer and Locktite thread locker on the assembly below the trigger as some of those have loosened and caused the trigger to wobble.

Do your troubleshooting one step at a time. Be systematic. The systems are very simple and straightforward. Try one thing. If that does not work go on to the next. You will get it figured out. Above all, make sure the engine is running perfectly before you try taking off again. I am sure your last flight was scary. Lots of good people here and at Sonex that can help you get back up.

Jake