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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 13581
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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I have a Deere / 1998 Sabre / Model: 2048HV / JD Product No:

Customer Question

I have a John Deere / 1998 Sabre / Model: 2048HV / JD Product No: M02048H010257
Briggs & Stratton Engine: 20 HP V-Twin Vanguard / Mfg. date: 8-9-1997
Model: 351777 Type: 1114-E1 / 3680 Code: 97690419
This motor has a Nikki Dual Venturi Carburetor: Model: 75N 808240 621266-041
The higher the rpm, the richer the engine runs. (black smoke at full throttle). I have replaced the air filter and it still runs the same. I removed the carb and cleaned it. I am 76 and was an auto mechanic for years. If I remove the Air Filter, the engine seems to run perfect at all rpm. The Engine has a 394018S Briggs Air Filter on it. This one has me stumped. Please help.
Submitted: 1 year ago.
Category: Small Engine
Expert:  Curtis B. replied 1 year ago.

Air cleaner is correct, but are the openings in the housing open , to allow the air to enter the housing freely? See the link above. Your choke is wide open and not closing when you throttle up? Your carburetor is not one that is used on many engines. Looks like the standard pulse fuel pump, so fuel pressure is not going to be too high.