# Differences/similarites HS621 to HS521



## lmichael (Nov 5, 2019)

So I have an HS621, and from my understanding the HS521 is nearly identical. Since parts are hard to come by and expensive for the 621 I stumbled onto a HS521 that has a broken recoil starter but has electric start. Owner says engine spins over with electric start but will not start.
The machine looks to be in nearly mint condition and owner is asking $50. I am considering buying it as a parts machine. Worth it? My 621 is on the beat up side but the motor runs well. The auger housing though is banged up and chute has seen better days. 

Thinking I could swap the 621's motor over, convert to electric start and keep the rest as spare parts? How far fetched is this?
Or am I better off fixing the 521 up and selling the 621?


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## orangputeh (Nov 24, 2016)

lmichael said:


> So I have an HS621, and from my understanding the HS521 is nearly identical. Since parts are hard to come by and expensive for the 621 I stumbled onto a HS521 that has a broken recoil starter but has electric start. Owner says engine spins over with electric start but will not start.
> The machine looks to be in nearly mint condition and owner is asking $50. I am considering buying it as a parts machine. Worth it? My 621 is on the beat up side but the motor runs well. The auger housing though is banged up and chute has seen better days.
> 
> Thinking I could swap the 621's motor over, convert to electric start and keep the rest as spare parts? How far fetched is this?
> Or am I better off fixing the 521 up and selling the 621?


I also have both but not much experience. the 621 was easier to work on cause on the 621 the carburetor was easier to get to and clean out. 

$50 is pretty cheap. I don't see how you could go wrong. I also have the Honda shop manual bought for $45. It covers both these models.

From what i read here the 621 is considered one of the best single stages out there. It took me almost 3 years to find one. I could have sold my 520 for $500 but changed my mind on selling it cause I like it too much.


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## lmichael (Nov 5, 2019)

I ended up buying it. Auger is in good shape, as is the housing (except for a little wear and damage on the non belt side), needs rubbers and a scraper bar, I did not look inside the belt housing, electric starter works and much to the guy's surprise and mine when he went to show me the engine started right up and sounded strong. It was advertised as a non running parts machine so this was a bonus. The recoil is broken due to an amateur repair attempt but I see I can buy entire new ones on Ebay for less than $30. 

I am sure there will be a couple other little items I will find but honestly when the engine fired off as strong as it did for $50 it was sold. I handed it over and took the chute off and loaded that baby right in the back of my Highlander. 

I will do more evaluation as time permits and hopefully have it fully operational soon. 

I do know it has the same carb malady my 621 had. I kept my 621 carb so maybe I will take it apart and rebuild it, install it on the 521.
Anyone found why/where these carbs leak? It's not needle and seat as engine continues to run as normal


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## tabora (Mar 1, 2017)

lmichael said:


> Anyone found why/where these carbs leak? It's not needle and seat as engine continues to run as normal


Usually either the float sticking/needle not seating or the bowl gasket or the bowl nut washer.


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## lmichael (Nov 5, 2019)

BTW anyone ever bought one of those recoil starters from FleaBay. They're aftermarket and pretty cheap.


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## orangputeh (Nov 24, 2016)

lmichael said:


> BTW anyone ever bought one of those recoil starters from FleaBay. They're aftermarket and pretty cheap.


junk. yes i have one. 

try boats.net


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## lmichael (Nov 5, 2019)

I bought one of the new recoils from Amazon https://smile.amazon.com/gp/product/B01BT4VFT0/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 and the overall quality does not seem much different than the OEM that the previous owner screwed up. Though one thing I do notice is the chord is much shorter. So on a piece of equipment where the engine is exposed I think it would be fine but on the snow blower you lose about 18" of chord to get it to the eye hook. 

Still have not had time to really get into it though and really get it running well. It is having issues staying running. Sounds like it's leaning out real badly. But when time and this flu bug I have caught permit I will get after it more


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