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

I have an older Ariens ST504 that I picked up at a garage sale a few years ago.  It has run fine until a few weeks ago.

I last used it about 3 weeds ago.  Toward the end of blowing out driveways of all the neighbors, it started bogging down when under load.  If I stopped the auger and drive, the rpms would pick up again, but fall off as it got back under load.  Also, the throttle lever no longer responds, it seems to only work in the wide open mode.  I can slide the lever down to idle & back up again but it stays runnig full bore.

It was really cold that day so I thought the throttle linkage was just frozen up.  But the same thing happened today, and we have had a warm spell in between.

I have a feeling it's the governer.  I'm not familiar with how this works, I'm used to machines with throttles that I control!

I have downloaded the manuals for it, but they don't address the engine or carb.

I'm hoping someone can help me out with this, otherwise it's off to the small engine repair shop.

Dave in WI

Hi Dave, before doing anything just make sure that the auger/impeller assembly is working properly. For that, remove the spark plug wire from the plug , remove the pulley cover and try to turn by hand the impeller pully a couple of turn, you've got to make sure again that this part of the system is in good condition, if OK reajust your governor to check if it's out of ajustment

Click here

Sounds like you snow thrower has been sitting for sometime......   Sometimes the evaporating fuel will gum up the throttle shaft in the throttle setting it was parked in..

When this happens the engine runs fast with no load,    when the engine tries to respond to the demand,  the governor can't moive the throttle to give more fuel..

This "stuck throttle" can also happen in the slow position,  If the engine tries to take a load the engine stalls and dies..

The handlebar or throttle control knob does not have a ridgid attach point,  so all you are moving is the spring not the throttle shaft..

Try moving the throttle shaft on the carb by hand it should move to both stops and spring back to set position with a "snap"...   if it feels like the throttle is "gummy" and does not react back from your movements,   spray it with a solvent or cleaning/lube oil and work it free..

Good Luck,

Friiy