Jsno

I would open up the top fuel tank panels. Drain the fuel and flush with clean fuel. Flush the entire system. It could have been water, poorly applied slosh coat, or the tanks were not thoroughly cleaned and flushed after reseal. Also could have water as stated in other posts. Could be more than one thing. Those tanks need to be surgically clean to be safe. Also check the drains when opened.

Check with Mooney salvage yards for the vent piece. I would just paint the knob with blue paint.

When I overhauled my IO360A1A, DIco had welded that area and tapped the hole. It was a straight thread and the fitting was a pipe thread. I bought a straight thread fitting ewwith an O-Ring seal and it worked great. The previous overhaul had installed the pipe thread fitting with sealant. Not good. May be why it was cracked. This could be the source of your leak. Remove the fitting and check the threads on the case and the fitting to see if they match.

I would need to see another picture. This one shows nothing.

EBAY

I just bought a used gear set in excellent condition for $140.00. It is the 20:1. My M20F has 5000 hours and the gear is still in great shape, so with the spare I think it will last longer than me. The key is to lube them with the proper grease frequently.

Pass on it. I bought an estate sale Mooney and wound up spending over 60K on it. I have an IA so the labor was free. It’s the small stuff that will nickel and dime you to end up eventually amounting to big bucks. The cheapest aircraft is one that is currently flying and well maintained.

I removed the galley from my Mooney so no smell!

Same stuff as the airlines use.

I would go with an overhaul. Use the money saved for avgas.

I installed coin mat in my M20F. I like it much better than carpet.

Thanks. Stuff works great.

Sorry about the misspell in earlier reply. It is DiOxit not Dioxin.