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Something to Check...

Posted: Tue Sep 07, 2021 1:08 pm
by SurfLung
When You Can't Get the Engine Started...
Here's Something to Check...
- My little 1980s Aerotecnica Coltri MCH-6 suddenly stopped running in the middle of a fill. I checked and added gas though it didn't look like it was out. But it would not start. I took the air cleaner off and primed it with fuel. It started for a brief moment and died. So I figured it wasn't getting gas.
- So now I blew into the carburetor with my mouth... And instead of hearing bubbles in the gas tank, I heard my breath coming right back out very close to my ear. Hose connections looked solid. I blew again and that's when I spotted it. The screws holding the carburetor onto the engine had vibrated loose and there was a 1/32nd of an inch gap between the carb and the engine. No wonder it couldn't suck any gas!
- So... I simply tightened up the screws and the darned thing started up lickety-split and ran just fine.


BTW - When I rebuilt this compressor, I replaced all of the gaskets and diaphragm in the Briggs and Stratton carburetor and fuel pump. I had the carburetor completely taken off while doing this. There weren't any lock washers on these carburetor screws. I thought of using Loctite when re-installing the screws but Loctite softens up when it gets hot. Anyway, I think I'll round up some lock washers so this won't happen to me again.

Re: Something to Check...

Posted: Sat Oct 02, 2021 10:34 am
by captain
Gas driven compressors suffer from harmonics. Each machine has it own vibrations frequency and somewhere in the frequencies spectrum there is a merging of the two machines which amplifies the vibration. Keeping things tight is always a problem, lock washers/nut and locking compound are your friend.