Mccormick Deering 10-20 carb and mag help needed

fordpower30 · Jul 14, 2011

Hello,
I have restored a "29 10-20 about 4 years ago. Since then I have had problems with the carb and mag.
I have the mag firing good at TDC, but when I advance the timing it seems to be going to far. It has a Bosch Mag. (i think e4b??)
Also, I installed a new needle and seat in the carb to lessen my fuel bill... but now I cannot get it to start. It seems to have too much fuel on choke, and not enough open. I checked all the gaskets, which seem OK. idle needle is 2 1/2 turn out, fuel needle is about 1/2 turn out.
I have no luck with carbs, any help is greatly appreciated.
Thank you,
Tyler Martin

Oldiron29 · Jul 15, 2011

fordpower, When you set the mag you should be TDC and full advance. Back up your seting one hole. I think you need main fuel jet on top of carb open 2-3 turns 1/2 is not enough.
oldiron29

fordpower30 · Jul 15, 2011

If I set the mag back a hole, it won't fire until after TDC. Do I need to change the timing in the mag so it is at full advance when the coil trips at TDC?
Also, 2-3 turns out on the fuel jet has the screw almost all the way past the finger that holds the teeth on the outside of the screw. does that sound right?

Thanks, Tyler

James Williams · Jul 15, 2011

Fordpower,Forget the advance rod.Leave your rod at the off position.set your mag so it will trip at TDC,piston at full extension and the crank pin at a horizonal position.When you start it you move your advance rod just a little off of the stop position and this will retard your mag to give your crank time to move toward the downward position of the piston,this keeps it from kicking backwards.After your motor starts you should be able to move your advance rod all the way down and you should hear your motor smooth out

36F30 · Jul 15, 2011

Initial settings by the book for the model R carb on the 10-20 are: the fuel adjusting screw on top of the carb out one and a half and the idle mixture screw on the bottom out two and a half

If you installed a new needle and seat to lessen your fuel bill, does that mean it was leaking fuel? are you shutting off the fuel petcock every time you shut down the engine? That carb is not designed to, or capable of holding back the fuel when the engine is not running.

I'm looking for the timing procedure for the bosch, I think I have it somewhere.

fordpower30 · Jul 16, 2011

Great, Thanks.
The needle would not hold back fuel. it was too corroded. I look
forward to the timing procedure for the Bosch. Thank you.

Mccormick Deering 10-20 carb and mag help needed

fordpower30

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