Bad check valve

[Sirolf]

Hi..

i run a OS 91 HZR and it is starting to lean out on me past couple of flights. Very noticable in when doing things inverted. Just started doing inverted auto's and everytime now it comes down sounding lean.. it has a high dingdingding idle attitude.
After chaking it a little i noticed it dies everytime i keep holding the heli upside down at idle.

Replaced the clunck line last week and still waiting on the trexstopper tank grommet. After a flight it has a very decent pressure in the tank.

So i wonder how can you tell when a check valve is going bad? If i hold it upside down wouldn't i see air being fed to the tank coming from the valve?

[Lighty]

Spin the clear bit around. Under magnification it has two different surfaces.

[Sirolf]

Before taking it apart yesterday i did the blow test and was easier to blow through than after i took i apart and cleaned it.

Honestly don't know which side around i refitted the silicone valve.

[Sirolf]

New check valve in, replaced all fuel lines,filter , new MOAS in the tank, inspected the regulator yet again and it is spotlessly clean inside. Both needles on the rich side and still
it has moments it leans out. Smoke is good.. has a nice trial at long climb outs and transition to the mid range is also very good.

Getting in to a climb out after hovering for 10 seconds or so it hesitates a bit like it's stupid
rich..

Any ideas?

Will take the carb out tonight and tear it completely down for inspection

edit; also when i hold the heli upside down while idling it dies after a second or 10

[rctintin]

I like to leak test all my plumbing. Remove tank and all pipe work, and plug the engine end with a M3 bolt. Now use a pump with a needle valve on it (football/basketball inflater valve). Do this from the back plate end and pushing air through the check valve. Dunk the whole lot under water in the sink and look at your tank seals etc for bubbles.

Also, they are so cheap, don't mess with check valves, after about 15/20 gallons of fuel, the silicon seal super polishes the alloy seat and it has a very high surface tension. It's fine once you have cleaned it, but within a few mins running, the oil effectively seals the two parts together, and you loose tank pressure straight away, and go lean. Just buy a new one, and how the old one away.