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

Hi folks,

I have a large 11.5 hp Ariens snow thrower for those times when we get dumped on but for lighter nuisance type snowfalls I just purchased a used Ariens Metro 4hp snow thrower.

The plastic body Ariens Metro looks exactly like the modern single stage snowblowers but it is in fact a 2 stage snow thrower.  The rubber tipped front augers turn slowly to pull the machine along and they also feed snow to the small impeller blades.  The small impeller blades spin rapidly when there is no load.

However under a load of just a two inch deep snowfall the small impellers lose power and are barely able to push the snow out of the chute...even when I hold the machine back to a crawl.  The 2 cycle engine seems to run strong...and the front augers seem to have plenty of power.

Does anyone have an idea of what could be causing the power loss to the impeller?  I'd hate to trash the machine if it just a simple fix as it still looks and starts great.

Thanks,
Paul

If it helps I pasted the electronic manuals on the Ariens Metro that I found on the Ariens web site.

http://apache.ariens.com/manuals/037097A.pdf
http://apache.ariens.com/manuals/SM-937-91.pdf

do you have broken shear pins?

Not sure because I didn't take anything apart yet.  Would the impeller still turn under no load if the pin was broken?   If it would then I can't rule out a broken pin.  Looks like the pin is part number 33 on the parts diagram...I'll check it.

with the machine OFF turn the impeller,if it spins,you have a broken shear pin,if it does not spin,there is something else wrong,maybe a belt.

It doesn't spin but I can move it with some force.  

what does it do with the machine on and auger in drive mode? if they are both turning good,it probably is'nt a shear pin.

They are both turning.  I noticed a compression spring that's used to adjust the auger/impeller belt tension.  I'm going to try and fiddle with it.