Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

My Ariens 831b Snowblower starts and runs well.  I can set the carb up to run very smooth.  I can adjust the throttle down and up, but when I engage the drive and blower clutch at the same time the engine fades and cuts off after about 30 seconds.  I don't have any more ideas.  It seems like it has to be a fuel delivery problem.  Any ideas.

Your symptoms do sound fuel related.  Before working on the fuel system, do a spark plug swap first.  I've seen spark plugs work with no load then stop working when under pressure.  It's very rare but still a possibility and an easy test. 

Make sure all of the running components, i.e. auger, impeller, drive wheels etc. are not seized or have bad bearings.  Disconnect the spark plug and ensure all components run freely by turning them by hand.  Once you've established that area is good, look at your fuel system.  Check the tank and the line to the carb to make sure you have good solid fuel flow.  If you have a filter, check it too.  If fuel to the carb is good, pull the fuel bowl off and look for dirt & water mixed in with the fuel.  Check the float needle very closely to ensure it's opening and closing without obstruction.  The parts are very tiny and if doing a visual inspection, a strong magnifying glass will help.  While the carb is apart, you might as well give it a thorough cleaning.  Remove as many components & jets as possible, thoroughly clean each one, blow out all passages with compressed air and if necessary, use a very thin,  stiff  flexible wire to clear passages.  Good luck.

The easy stuff first, IMO.

When you engage the blower there is a higher demand for fuel. If the gas tank gas cap is slightly clogged, a small vacuum may develop in the tank. Just for the heck of it, try running with the gas cap completely removed. Also make sure the fuel/air mixture screw is adjusted for a loads under blowing snow conditions. A lean running engine can bog down under a load.

Good thinking.   I forgot about the fuel cap vent possibly being blocked. 

If any of those mentionned are Ok I would check for the governor ajustment? an engine that,s run freely demands a very low power but....when loading it,s different

GOVERNOR ADJUSTMENT

With the engine stopped, loosen the screw holding the

governor clamp on the governor lever. Rotate the clamp

in a direction that will force the throttle shaft open and

allow the governor follower arm to rest on the governor

spool. Push the governor lever connected to the throttle

to the wide open throttle position. Hold the lever and

clamp in this position while tightening the screw

it has been mentioned above and i agree.set the carb  slow speed and mixture screws for full load. you can do this by fine tuning the slow speed and main mixture screws a little richer. i adjusted my slow speed so that when i open the throttle swiftly it does not balk too lean or load up too rich and cough black smoke out the carb. one setting affects the other so it's a combination of the two that makes the final full throttle mixture.once the slow speed is adjusted i throttle wide open and run the mixture screw in till it coughs or slows the speed down then out till it slows down (too rich). most would set the mixture in the middle between these two extremes and it is a good starting point but just a tad richer might elliminate your problem.you may have to do this a couple of times to fine tune.your objectives are.1 a good idle (you might have to raise it a bit to compensate for the richer mixture ) 2 when swiftly opened to full throttle it does so with very little or no hesitation. 3 under full load blowing snow the engine runs smoothly and has sufficent power to sustain itself. 4 when all done with adjustments the engine cold starts with no problems. you can tell if you get all four of the adjustments right when you start it cold and take note of how much choke is needed once started,if your adjustments are lean it will need the choke longer than usual to run,too rich and you can within 30 seconds remove the choke completely and place the machine under load.take note of the cold startup performance!it will tell you what to do. by the way both the high and low speed needle preliminary adjustments are 1 1/2 turns out from lightly seated all the way in,and these adjustments will vary with the final tuning of every machine. hope this helps mike.