1020 Carburetor Problems

Gumbi · Sep 25, 2019

I'm attempting to rebuild the original marvel schebler carburetor on my 1020 right now and have run into a couple issues. The fuel bowl was leaking badly and it
idled badly and was extremely dirty which is the reason for the rebuild. I've rebuilt the carb recently for an 8n and they are fairly similar so I'm confident in
my ability here. When disassembling it last night I found both the idle jet and load jet/nozzle to be severely buggered up and would not unscrew out of the carb
bodies. I soaked them in some PB blaster a little while and tried heating it gently with a small torch but got nowhere. I soaked them some more and will try again
tonight. In the meantime I will need to replace both of these parts. Where can I find them? I haven't called deere yet, but I imagine if they have them they will
be crazy expensive there. Anybody have a good idea to help remove these two from the carb body?

Secondly, the shutoff solenoid was replaced at some point and does not have the adjusting screw on the back like the manual shows. How am I supposed to adjust the
fuel flow with no adjusting needle like the service manual says? Is it just metered correctly with the size of the jet? Would it be better to replace this
solenoid with a manual screw adjusting needle?

Thanks

Bob · Sep 25, 2019

(quoted from post at 09:29:59 09/25/19) I'm attempting to rebuild the original marvel schebler carburetor on my 1020 right now and have run into a couple issues. The fuel bowl was leaking badly and it
idled badly and was extremely dirty which is the reason for the rebuild. I've rebuilt the carb recently for an 8n and they are fairly similar so I'm confident in
my ability here. When disassembling it last night I found both the idle jet and load jet/nozzle to be severely buggered up and would not unscrew out of the carb
bodies. I soaked them in some PB blaster a little while and tried heating it gently with a small torch but got nowhere. I soaked them some more and will try again
tonight. In the meantime I will need to replace both of these parts. Where can I find them? I haven't called deere yet, but I imagine if they have them they will
be crazy expensive there. Anybody have a good idea to help remove these two from the carb body?

Secondly, the shutoff solenoid was replaced at some point and does not have the adjusting screw on the back like the manual shows. How am I supposed to adjust the
fuel flow with no adjusting needle like the service manual says? Is it just metered correctly with the size of the jet? Would it be better to replace this
solenoid with a manual screw adjusting needle?

Thanks

WHY do you feel that you have to remove the jets, unless the passages behind them are all varnished up there's no real need to remove them.

If you feel you must, remove any an ALL parts that may be damaged by heat, and put the castings in an oven at 400 for an hour, then allow to completely cool, and likely the brass jets will come out easily.

If NOT, be prepared to drill them out carefully, and order the special taps needed to clean up the holes.

Main jet/nozzle is Marvel #47-455, and idle jet is #49-101L, you can get BOTH from Mcdonald for less than $25.

As to the non-adjustable fuel cutoff, some engines will run just fine with one, you won't know until you get the carb clean, together, and installed.

Gumbi · Sep 25, 2019

Yeah that's the thing. There is a heavy amount of varnish built up inside all over the carb. It really does need a complete cleaning.

Bob · Sep 25, 2019

You will be surprised at what an hour @ 400? will do to the varnish.

Gumbi · Sep 27, 2019

Was finally able to get those two jets removed. Had to use a screw extractor and some good heat. Have new ones order and will be delivered soon to replace.

Im seeing that these marvel schebler carbs are fairly hard to find. Seems the goto thing that all the parts suppliers have is a replacement Zenith carburetor. A Zenith was an option looking at the parts manual. Is there any difference in performance between these two types? Is one preferred over the other?

1020 Carburetor Problems

Gumbi

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Bob

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Bob

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Gumbi

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