Small Engines (Lawn Mowers, etc.): Briggs & Stratton Replacement Motor, briggs stratton, rnt

Question
Can you please tell me what replacement motor I would choose for my MTD tiller?  It currently has a model 13092; type 1916-01; code 85011607 Briggs & Stratton

Answer
Here is the link to the engine sales manual:

http://www4.briggsandstratton.com/miscpdfs/RNT/2009%20Replacement%20Engine%20Spe...

Is there a digit missing from the model number?  I tried to look up the engine...should be a 1985 model, 5 HP, but the model number should have 6 numbers.

Eric