# Toro 621 qzr 2014 model surges



## SuperiorArienRace (Jan 12, 2018)

I bought two toro 621 qzrs new at the same time I think 2014 models. One gets more abuse than the other. This year the one that gets more abuse seems to be surging when no choke is on but it can kinda clean up with half choke.Also its not major major surging but enough to know something is off and not running smooth. I took the whole carb apart except the choke pieces and the throttle flap pieces. Everything was pretty clean. Nothing major but I still used a wire and carb cleaner on every area I could. I 'm going to change the spark plug but I don't think that is the problem. I don't know what happened this year. any ideas?


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## Motor City (Jan 6, 2014)

Their are tiny passages that are probably still plugged up. I use an ultrasonic cleaner, to clean carbs. But the carbs may be cheap enough to just replace. Check ebay.


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## jtclays (Sep 24, 2010)

123


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## SuperiorArienRace (Jan 12, 2018)

I don't think i removed or unscrewed anything from the top. The only thing I recalled from the top were two mechs for the choke and whatever you called the throttle.


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## jtclays (Sep 24, 2010)

777https://www.jthomasparts.com/520-87...mio8zr5obr2aiva7xach1ana_neaqyayabegkjk_d_bwe


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## Snowbelt_subie (Dec 20, 2016)

jtclays said:


> If you use the "mouse over" zoom on the pic in this ad you can see the throttle stop/idle screw. Under it is a black "plug". Mark, measure or count the turns to remove the throttle stop screw completely, take a small flat blade and ease the plug out of the carb body. It is the pilot jet. It'll have a fairly large hole crosswise through it's body with a very tiny little hole in the end of the body. Use one strand of a wire wheel/brush to clear it and a little carb spray. If you already cleaned the main jet and emulsion tube previously and still have a little funky running, this will usually clear it up.
> https://www.jthomasparts.com/520-87...MIo8zR5ObR2AIVA7XACh1ANA_NEAQYAyABEgKJk_D_BwE


i have a 621e that was doing the same thing i tried cleaning the carb removed all jets ect. it was still surging. so a $13 carb from ebay is on the way.


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## DuffyJr (Oct 15, 2015)

Would a guy want to try a cleaner like Star Tron. It worked on my old MTD when it started running rough one winter. Now I add little every time I fill the tank.

https://www.amazon.com/Star-brite-Enzyme-Treatment-Additive/dp/B00EZSPU3U


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## SuperiorArienRace (Jan 12, 2018)

I will try cleaning that and see what happens. Getting a new carb is an option but aftermarket vs oem????? I also use Marine(blue color) sta-bil fuel treatment with plus or premium fuel.


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## Snowbelt_subie (Dec 20, 2016)

Found 2 problems with my 621 second hand machine. While draining the gas I noticed it was draining slow. 

I found i little screw in the tank partially obstructing the exit. I got it out and with the old carb was still surging a bit but was better.

Put the new eBay carb on and it runs like a dream now just used it in 6-8 inches.

Sent from my SM-G950U using Tapatalk


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## SuperiorArienRace (Jan 12, 2018)

I have mine set aside for the moment working on my other large ariens. It's running better but not perfect .


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## ewarnke19 (Dec 1, 2018)

I have a 621E i just booted up for the winter and the idle with no load so much higher to the point it sounds like the engine will blow. Do you think it could be stale gas or too much StaBil? or could it be the choke linkage or idle screw? if i pull out the choke is reduces to normal running idle but increases as it shakes the idle knob. 

Thanks! Ed


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## Motor City (Jan 6, 2014)

Sounds like the throttle is stuck, or governor linkage. Any chance mice might have got into the blower during summer storage? Bad gas or Stabil wouldn't cause this.


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## ewarnke19 (Dec 1, 2018)

Well, i took the cover and discovered that the throttle was frozen! Put some penetrating oil on the linkage, cleaned the carb with gumout and it's working great now (small oil leak but manageable). Thanks again. Ed


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## renegade:32 (Jan 8, 2018)

Mine never surged. 

UNYIL....I put new paddles on and I tipped it back on its handle to install the replacements. 

Should I:
-drain and refill the gas tank?
-take apart the carb to clean it, (or replace the carb)?
-just run it until it clears itself out?

Opinions welcome!!

Thanks—


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## Snowbelt_subie (Dec 20, 2016)

renegade:32 said:


> Mine never surged.
> 
> UNYIL....I put new paddles on and I tipped it back on its handle to install the replacements.
> 
> ...


Surging is a lean issue it's not getting enough fuel. Make sure the line from the tank flows freely. 

I would just bolt a new carb on for $10-15. If you are feeling frisky you can clean it. It might clear it up it might not.

Sent from my SM-G950U using Tapatalk


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