[GeneralLee]

Hello there,

I am new to site...

I have a john deere lawn tractor with Briggs 20 hp vanguard Twin motor. When I either go from idel up to full throttle fast or I am at full throttle and engage mower deck, then engine surges and black smoke billows out. I have replace the crank breather and govenor spring, notice oil in the carb intake and filter. The plugs have a black sut on them. I have been reading here, but haven't really found the same issues I have. I am thinking rebuild carb next?? Seems that the black smoke is a air mixture issue, I have tried adjusting carb but it seems like its not doing much. Also the sut on the plugs indicates to me that not getting enough air. Hope I am on the right track, use to work on these things daily 25 years ago but seems I have lost my touch...

Rob

[MOWERMAN2468]

Yes you are on the right track. The black plugs is an air / fuel mixture problem. You are running too rich. I would suggest a thourough cleaning of the carb. Are you still getting oil in the air filter and housing? If so the crankcase breather is bad, or hung. Was the area clean before installing the new crankcase breather? It only takes a small speck of dust to hold the flap open and allow for the oil to be pressured into the carb.

[GeneralLee]

Good Morning mowerman,

After replacing the crank breather there is no indication of oild in the carb throat. I seem to have solved that problem...
So now I will try and loacte a rebuild kit for the carb. I look extensively on line last night and no one seems to carry it. I went to briggs site and they cross referenced it ti a new number # 842871. I will look further for it today. If you know where I can get one it would be appreciated. Again thanks for you confirmation on my therory. I keep you updated.


Rob

[MOWERMAN2468]

The reason you were cross referenced to a new number is because the briggs and stratton parts seem to quite frequently supercede part numbers. So just because the part number is different, does not mean it is the incorrect part.