MD fuel needle adjustment

sflem849 · May 30, 2011

Is there a way to adjust the fuel needle to get it to stop the fuel flow when on diesel? When I reinstalled the linkage, could I have done it wrong so that it doesn't even try to stop the fuel flow? It looked like there was only one way...must have had bad mental pictures :lol:

Ran the tractor for about 30 min tonight without shutting the gas off. When I went to switch back to gas it had drained at least half a tank. Not good.

Also, when I opened the drain on the bottom of the carb (bc I was in disbelief that it ran out of gas) the tractor started running really rough. Why is that? Should it do that? It was on diesel at the time.

LaBoyteaux · May 30, 2011

I had one of these apart recently. The float needle itself is not
adjustable, assuming it is not leaking, all adjustment is in the
linkage. Best to get a manual and go through the linkage
adjustment by the numbers. The gas intake manifold is not
difficult to remove and allows access to the linkage plus
checking the butterfly valves. The gas/diesel system worked
well, when it is right.

M Diesel · May 30, 2011

Easy enough to check the needle. Should be nothing out the carb drain when on diesel. (After the bowl drains of course.) Make that work correctly before doing anything else. I don't think I've tried opening the drain on the MD running, but have on the big engines with no effect.

How is the air cleaner condition? Front end drag will affect how the carb is treated.

sflem849 · May 31, 2011

There is no description of how to adjust the needle in the starting lever adjustment section. I didn't look at the carb section when I did the starting lever adjustment. I started at the head and worked back to low idle so I would have done it somewhere in there.

When I put it back together the first time I know the needle was seating relatively well the first time because the sediment bowl would only fill with a drip when the lever was in diesel. When I put it back together after doing the head it didn't seem to shut the gas off as well. Maybe I will pull the carb. :? It likes it's choke anyhow so it could use a cleaning.

M Diesel · May 31, 2011

Basically nothing to adjust. It is kinda spring loaded.

It running rich is making sense now. Definitely pull the carb and check the seat. It is pushed closed in diesel so even a bad float isn't an option.

Where fuel line comes in at the front side of the bowl there is a little cavity in there. The fitting itself should have a screen attached. For one, the screen fails. For two the cavity also fills with crud from the starter tank. The crud drifts upwards towards the seat and can muck it up. The setup is very tolerant of debris, but limits are limits. Make sure the whole mess is clean.

sflem849 · May 31, 2011

(quoted from post at 14:47:11 05/31/11) Basically nothing to adjust. It is kinda spring loaded.

It running rich is making sense now. Definitely pull the carb and check the seat. It is pushed closed in diesel so even a bad float isn't an option.

Where fuel line comes in at the front side of the bowl there is a little cavity in there. The fitting itself should have a screen attached. For one, the screen fails. For two the cavity also fills with crud from the starter tank. The crud drifts upwards towards the seat and can muck it up. The setup is very tolerant of debris, but limits are limits. Make sure the whole mess is clean.

That screen is a little smashed. I remember that from when we put the head back on. It was on the "I'll remember to replace that someday" list. I never remember that list...

MD fuel needle adjustment

sflem849

Well-known Member

LaBoyteaux

Member

M Diesel

Member

sflem849

Well-known Member

M Diesel

Member

sflem849

Well-known Member

Similar threads