YS engines and fuel leaks

[Leebert]

Nearly completed the Vibe tonight and I turned the engine over and, once I'd put the check valve the right way around , I noticed I had a fuel leak.
It seems to be coming from around the edge of the rubber bung that holds the clunk in the tank.
This is my first YS pressurised system so I am on unfamiliar ground but I have cleaned up the hole in the tank where the clunk goes in with alcohol but it still leaks. The hole looks neat and clean.

How do you guys go about sealing leaks with a YS pressurised system?

Thanks for your help

[mattie-lodge]

Interesting dude. Never had that. Maybe the bung has lost it's shape slightly. If you have no luck I will order a bung kit for you from RR.

Cheers

[Leebert]

Thanks Mattie.
I'll check it out for shape. I'm sure it's summat simple like a bit of crap in there.

It was a real buzz to be actually in a position to start it if that makes sense.

Watch out for Mrs Leeberts maiden flight soon - it's quite exciting

[rspblake]

Try cleaning the bung inside where it seats to the tank with the same cleaner..

[Steve]

You can get some fuel tube clamps (packs of 4 I think) from regular model shops - little springy key-ring type things that clamp the fuel line onto the nipple. You'll need loads for a heli. I got them on my YS90, but not on my YS50, both of which use the same positive pressure system.

Dunno why I fitted them to the 90 really, they just seemed like a good idea at the time - maybe I though the 90 would produce more tank pressure than the 50, but most people with 90s don't bother, and don't have an issue.

Although there is pressure developed in the tank, I've never known it to be enough to blow off a fuel line.

The leak is more likely to be something simple like a plastic mould flashing breaking a seal or something.

[Steve]

Oh, and when you go to start it Leebert - spin the engine over for 10 seconds at full throttle with NO GLOW ATTACHED first - this primes the pressure system and the fuel lines.

Then drop the throttle to normal start tick-over position and start as usual.

[jiberjaber]

Yup - as above, but I find it takes a little longer to pressureise on the first tank of the day, say about 25 seconds or so of starter with the throttle open.

At the end of the last flight of the day, I stop the engine with the fuel clamp and let it burn out the last of the fuel and then de-pressurise and remove any left over fuel.

If you forget the above, then clamp and spin over with teh glow on to burn off any nitro left in the engine.

I had the spring fuel clamps on mine when I had the raptor, didnt bother with them on the knight.

[Leebert]

Took the tank out this morning and removed the clunk. Spotted that the rubber bung that seats the clunk to the tank is split on the inside.

Can you get these bungs seperately?

Thanks

[mattie-lodge]

I am pretty sure you can Lee. Will phone up for you on Monday morning

Can you PM me your address?

Cheers