carbueration

My TO 20 hasa marvel schebler carb. It won't run unless the choke is held out. So how would I proceed to fix this
thanks

I am not a expert by no means on carburetors but hopefully I can help you out. My thinking is when the engine needs the choke to run than it's not getting enough gas to fire so choking it will suck more gas and less air to fire better. Now like in your case it needs it all the time I would think that your not getting enough gas and too much air so maybe try adjusting the carb based on the Ferguson operation and Maintenance manual they tell you in there how to adjust it right hope that helps.

MS carburetor should have a drain plug on the bottom of the bowl. Remove it and check for good steady fuel flow. If this shows problems trace back through filters and fuel line to fuel tank and find the restriction.

If fuel is good, Check your ignition, weak spark can appear as fuel problem. Check points and points gap. Get a good set of points, not the cheapies that come in kits. Many model's points are set at .020 and plugs at .025. Be sure point gap is correct.

If none of this cures the problem, then suspect carburetor

Could be a few things as listed, also could be your manifold gasket has sucked in and is pulling air at the head.
Check your fuel flow, check for dist shaft wobble as long as your at it, I would be chasing a bad gasket before taking apart a working carb.

As said, check the spark quality, check for vacuum leaks, check fuel flow through the drain plug, try opening the main fuel adjustment screw 1/4 turn at a time.

If it still is too lean, the carb will need to come off and be opened up and cleaned. If it has been sitting with ethanol fuel in the bowl, chances are it is clogged internally. Inside there will be various fuel jets. The main jet is the most common to be clogged. Dried ethanol residue is difficult to remove, carb cleaner will not get it, it has to be scraped out with a small wire.

Don't be intimidated, the carb is simple and field serviceable. Lots of online information, parts break down, how to manuals, and Youtube videos to walk you through it. Just work over a clean surface so not to loose anything.

If the inside of the carb is dirty, chances are the tank is also needing cleaning. Best to take it off, dump it, rinse it with E85 gasoline if you can find some. Be careful handling and bumping it, as it is probably got some thin rusty places. If it is severely rusted and flaking, a replacement may be a consideration.

Inline filters are not a good solution. They don't work well with gravity systems. A clean tank, the screen in the sediment bowl, and the screen in the carb elbow fitting will be sufficient.

Thanks everyone ill try all tips beginning with spark thanks so much