Vintage Briggs - Need help with points and ignition coil

I have an MTD ride on mower with B&S 220707 0142-01 of 1979. Ignition coil is dead. Original 298968 no more available.
Is coil 398811 suitable? Can it be fitted direcly in place of old coil? are there modifications needed? I would not risk buying a coil and scrap it.
thanks for suggestions.
 
398811 is correct for your engine and available. It is a direct fit. Don't need the points so if still installed don't connect the points wire just the kill wire.
 
Thank you very much ILENGINE. So, with the new coil fitted in the old one position, the timing of the spark is correct on its own.
I'll fit the 398811 coil.
 
I bought and fitted the 398811 coil.
The motor started immediately but, at low revs it's OK, opening the throttle it runs unevenly, with strong bangs alternating with a few no firing turns. When just a little loaded it stops.
I thought it could only be a timing problem but the coil mounting is fixed and timing can't be adjusted. I deemed that the new coil was not fitted for my motor, so, as a battery will be always available for starting, I bought a 12 V car coil, I connnected it to the existing points and tried again. Good spark but same uneven behaviour. Now the timing is the previous one stated by the points. What can be the problem? Before changing coil it worked perfectly and I did not change anyting else than coil. Thanks for suggestions.
 
Did you checked to see if the flywheel key is partially sheared, which would throw off the timing. Second, did you set the coil air gap at .010”? Third, did you set the point gap at .020”?
 
Yes. Yes. Yes.
The flywheeel key (new, supplied with the coil) is sound, only has a very little play, not enough for upsetting the working.
 
Hello Ronnie,

What was the final solution to get you going again?

It helps to let people know that are following these posts when a solution is arrived at, so it will help others with similar problems.
 
I would try and replacing the spark plug. The fitted plug is an NGK BM6. I wonder if this is the correct type but can't find the type in the B&S Part List. Which is the correct plug for the motor 220707 code 120411 please?
 
Sandro said:
I would try and replacing the spark plug. The fitted plug is an NGK BM6. I wonder if this is the correct type but can't find the type in the B&S Part List. Which is the correct plug for the motor 220707 code 120411 please?
Click to expand...
Look at the code number again. Is there a -01 on the end?
 
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