Small Engines (Lawn Mowers, etc.): 5 HP Biggs & Stratton problems, engine model type, briggs and stratton


Question
QUESTION: Hello 2 questions for you - I have a Sno-Guard 5HP motor on an old snowblower I just bought.

It starts right up but if I lift the wheels about and inch off the ground with the handles and set it back down the engine starts to miss fire and often stalls right out. It then starts right up again ?

It also stalls at any RPM when being used sometimes recovering and sometimes not. It is not a fuel issue because if I prime it still stalls.

It has 60 - 70 PSI compression, a very good spark and no air restriction to carb ?

I have purchased a pumping diaphragm and new head gasket already - just looking for a little advise

Thanking you in advance

signed puzzled lol

ANSWER: What is the engine model, type, and code number?  Is the engine a 2 cycle or 4 cycle.  Can you attach a picture of the carburetor?

Eric

---------- FOLLOW-UP ----------

Small Engines (Lawn Mowers, etc.): 5 HP Biggs & Stratton problems, engine model type, briggs and stratton
Sno Gard Carb  
QUESTION: 4 cycle - model 5HP Briggs and Stratton sno Gard model 130212, type 0764-01, code 78062106

A little update for you Eric

Pumping diaphram changed, carb cleaned, head gasket changed, idle screw 1-1/2 turns out adjusted as per Briggs and Stratton manual.

Doesn't stall now when I lift wheels up and down but seems to have changed and be starving for fuel now. ( when I spray gas in carb and play with choke it sometimes recovers )

It starts to misfire without warning ( the spark and plug are 100 % )

see attached pic of similar carb

Just can't figure it out the points and condenser are the only thing I have not changed and adjusted.

I worked on it for about 4 hours and was only able to cut one path down my driveway through about 1-1/2 feet of snow lol

Hope to hear from you again with some other suggestions

Stephen

Answer
It is basically a 5 hp (13 cubic inch) block.  Very common engine.  Were there one or two thin gasket between the tank and carb?  Many of these engines used two thin gaskets.  Common problems this carb is warping, which is why 2 gaskets are sometimes used.  Also, the fuel pump cover is prone to warping.  You can check for warpage with a 10-12 inch flat file.  Just run the file across the parts in several directions.  The entire fuel pump cover should be shiny after a couple of file strokes.  Low spots will be dull in color...this how you know the part is warped because the file only removed metal from the high spots.

Points could cause the problem if they are dirty or the gap is wrong.  Have you ever replaced points?  I would most likely just clean the points and condesor with a point file, or fine sandpaper, gap and check engine operation.  I would set the point gap at 0.018 of an inch.  Check the point plunger as well.  Both ends of the point plunger should be flat and square.

If you can remove the carb on that engine and replace a head gasket the points should be no problem.

Eric