My son-in-law got the opertunity to run my engine first. Went I got home from vacating we ran it again and I was totally impressed with the starting ease, transition and the way it sounded and idled. BUT, when I installed it, it wouldn't continue to run. Just wouldn't do anything right. It's in a vector flight 300 which requires the tank be installed upside down. WELL,, I pulled it and sure enough the tank was in wrong. Installed it and tried again and it ran better but still not just right. I noticed that the tank had leaked a little from the vent tube and fule tube also. Not sure just where but there was fuel present. So we went ahead and tried to maiden it but it would die on taxi so I said forget about it, it ain't happening. It was an old tank out of his plane because the Tetra tank I ordered was too long. I pulled it when I got home and there was fuel on and around the fittings again so I ordered another Tetra from Central Hobbies. I have put everything back to original settings. High speed at 1 1/2 out, low speed at 1 1/2 out, and other thing flush with body. Anything else I need to do?? Do I need to use tywraps on the fuel lines? The Tetra tanks tubes dont have barbs. Will they stay on without tywraps? How long should I leave them? Here's a pic of my setup as is. It's really not as messy as it looks in the pic. I have filters in both tees, in the fuel line, in the can, in the tank, and on the fill tube. I'm using 20/20 YS fuel. And the glow plug from CH recommended.

Unless I'm seeing it wrong it looks like you have the check valve in the fuel supply line.

Hi there, and thanks for the reply. The red line is the fuel and blue the vent. All fittings are Tetra. I didn't use the check that came with the engine. The check is in the vent line between the engine and tee. The tee is also filtered. The fuel line has a crap trap filter between the engine and tee which is also filtered. I'm using dots from Central Hobbies. I have ty wraps on each fitting. I have a new tank on the way. A Tetra 12 oz. I think my plumbing is correct. I've been over it many times.

Good deal, I saw too many things there and didn't know what was what. I never use clips or ties whether YS or other with a regulator. I seldom use large fuel tubing though, with it you may need clips.

Blow into the check valve from front to back to see if it's facing the right way. You should be able to blow into the check valve from front to back and not the other way around. I think it's a plumbing issue.

I'll check it once more Richard.

The tank leak is a sign of a high pressure leak which means the tank needs to be replaced. You should be using medium fuel line in this app too so the tubing will properly fit the tees and fuel tank. Always use either an OS F or YS 4 glow plug in this and all other YS fourstroke engines. I am unsure why the tank has to be mounted upside down couldn't it be turned upside down when it is mounted so as to be installed rightside up when the plane is at rest. Resist tuning the regulator unless it is absolutely nessasary.

I'm confident that tank leakage is the culprit. Like I said, I've set everything back to specs and ordered a new Tetra from Central Hobbies. Concerning tank installation, the VF extra 300's wing is installed upside down, so access to the area is inverted. So when you install the tank, it has to be installed upside down. When right side up the tank is actually hanging by the tywraps.