# New to me 521



## paulm12 (May 22, 2015)

First of all, thanks to many on this forum. I have been reading up here for a few years, and I am continually amazed at the knowledge and willingness to help of so many members. I have a 1995 Toro 724 that I picked up a few years ago. I replaced all the fuel lines, cleaned and rebuilt the carb, painted the auger and housing, and replaced the auger and impeller bearings. Runs great. I don't need another machine, but I saw a used 521 (1988 I think) nearby this week and got it for $20. The owner could not get it to start, but it looked pretty clean, and had decent compression. I was able to get it running pretty easy (fresh gas, clean plug, etc), but it didn't run that well. So I will do a more thorough fuel system cleaning and fixing. I have the carb off (waiting for a gasket), and the starter and fuel tank off. I will replace all fuel lines and install a shutoff. Couple of questions for the team here. The PO installed an aftermarket non-adjustable carb. I assume there really is no adjustment, right? I have cleaned the fuel jet/bolt (??) including the small opening. Also, as seen in the pics, should I put a bit of oil on the engine pulley and the flywheel? They both have some rust, from sitting I assume. Thanks again for all the insights, info and references.


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## UNDERTAKER (Dec 30, 2013)

paulm12 said:


> First of all, thanks to many on this forum. I have been reading up here for a few years, and I am continually amazed at the knowledge and willingness to help of so many members. I have a 1995 Toro 724 that I picked up a few years ago. I replaced all the fuel lines, cleaned and rebuilt the carb, painted the auger and housing, and replaced the auger and impeller bearings. Runs great. I don't need another machine, but I saw a used 521 (1988 I think) nearby this week and got it for $20. The owner could not get it to start, but it looked pretty clean, and had decent compression. I was able to get it running pretty easy (fresh gas, clean plug, etc), but it didn't run that well. So I will do a more thorough fuel system cleaning and fixing. I have the carb off (waiting for a gasket), and the starter and fuel tank off. I will replace all fuel lines and install a shutoff. Couple of questions for the team here. The PO installed an aftermarket non-adjustable carb. I assume there really is no adjustment, right? I have cleaned the fuel jet/bolt (??) including the small opening. Also, as seen in the pics, should I put a bit of oil on the engine pulley and the flywheel? They both have some rust, from sitting I assume. Thanks again for all the insights, info and references.


*The carb question I will leave to someone that is more gifted with those things than I am. I farm that job out to my jet mechanic next door neighbor. as for the other question you do not have to anything to that it will rust no matter what. k:k:k:k:k:*


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## Jackmels (Feb 18, 2013)

Go to Ebay and get an adjustable carb. They are cheap and work well.


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## JLawrence08648 (Jan 15, 2017)

Oil and grease attract dirt, dust, plus the volatile ingredients evaporate. Use sparingly. Do not grease the flywheel it's unnecessary. Any rust will be removed as you use it.

Use synthetic engine oil.

Most times you need to use 7/16 OD fuel line, not 1/4" ID automotive fuel line hose which is half inch on the outside.

If the carburetor is not working correctly you need to remove the Welch plug on the side of the carburetor and clean the three or four holes using a welding tip cleaner. I always like to use a carburetor with an adjustment on the bottom at the fuel bowl. The cost of this carburetor from Amazon is less than $20. However IMO these carburetors are not as good as the original. Sometimes they come with a steel fuel bowl that will rust rather than an aluminum fuel bowl.


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## tpenfield (Feb 24, 2015)

I have a Toro 521 of similar vintage and absolutely LOVE the machine. Very agile. I recently replaced the original Tecumseh engine with the Harbor Freight Predator 212cc Hemi, picking up about 30% more power.

I got the machine from a family member who could not get it to start. A good carburetor disassembly/cleaning did the trick. Old fuel had gummed up the fuel bowl & float, and the carb was basically non-functional. So you are probably on the right track by doing a fuel system cleaning. The original carb had a needle adjustment on the fuel bowl. . . . not sure if a replacement carburetor would have the same.

*Also, as seen in the pics, should I put a bit of oil on the engine pulley and the flywheel? *
The rust is not really a problem, and I would not put anything on the engine pulley as that will tend to cause belt slippage. Drier is better

As far as the flywheel, be careful not to mess up the ignition by putting any grease, oil, or paint on the flywheel. Maybe take the housing off and do some touch-up paint. If you can get some rust-reformer paint, then that might be a good solution.

If you feel inclined, the Predator 212cc engine is pretty much 'plug 'n play' as an upgrade. I have a thread of swapping out the old 5 HP Tecumseh for the Predator. The Predator cost $100, and I sold the Tecumseh for $50, netting out to $50 for the upgrade.


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## unknown1 (Dec 13, 2015)

paulm12 said:


> ...The PO installed an aftermarket non-adjustable carb. I assume there really is no adjustment, right? I have cleaned the fuel jet/bolt (??) including the small opening.


Correct.. there is no adjustment except to re-drill the jet. I have had no luck with fixed jet carburetors (especially at altitude) and will never buy another. 
Give it a try and give it a thorough cleaning but be prepared to buy an adjustable carburetor if it doesn't magically "just work". $20 for the machine and $20 for a carburetor is still a sweet deal.


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## paulm12 (May 22, 2015)

Thanks all for the replies. I will go ahead with thorough cleaning of the fuel system and careful cleaning of the carb. And yes JLawrence, I do have the proper sized fuel lines. I would rather have the OEM carb, just because I have been able to get those running well in the past, but I'll give this one a try. And since the engine seems to have good compression, I'm hoping an engine swap wont be needed (at least for a while). Thanks for the references on the engine swaps. I'll do a little rust cleaning now, and then do an auger and housing repaint next summer. Too many projects already started now. 

Thanks again.


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## unknown1 (Dec 13, 2015)

paulm12 said:


> .. I will go ahead with thorough cleaning of the fuel system and careful cleaning of the carb....


Don't forget to remove the plastic cap and unscrew and clean the "air jet" up where the idle adjuster screw used to be on an adjustable carb... you didn't mention you'd already done that.


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## paulm12 (May 22, 2015)

Stuart: what plastic cap? here is the carb on and off the motor. The stamping on the carb is 5285. I don't have any schematics for it. Thanks.


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## unknown1 (Dec 13, 2015)

paulm12 said:


> Stuart: what plastic cap?...


You already got it... it's the screw-out sitting at the top of your second picture and to the left on pictures 3 and 4. 
On many (modern) non-adjustable carbs that screw is "hidden" behind a plastic cap that covers the screw-slot.

EDIT: By the way, I see on photo 4 that the emulsion tube seems to be red plastic. 
I'm not familiar with that specific carb but it's probably held in by one or two rubber o-rings.
If you still have problems after cleaning the carb, you might try popping out that emulsion tube and making sure the holes in the emulsion tube are clear and that the o-rings are ok too.
I've seen similar plastic emulsion tubes on lawnmower carbs and using too much carb cleaner in that area can dissolve those o-rings to a mush.
You might be able to reach in through the choke or the throttle butterfly and push downwards on the top of the emulsion tube with a screw driver.


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## Grunt (Nov 11, 2013)

stuart80112 said:


> EDIT: By the way, I see on photo 4 that the emulsion tube seems to be red plastic.


Here is a link to the carb stuart referenced-

Disassembly, Cleaning and Repair of Tecumseh Series 1 Emission Carb 640084B


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## paulm12 (May 22, 2015)

Yep, that's the link I once had and lost. Thanks. I got the emulsion tube out (I have the Tecumseh carb tool) and plan to replace. It appears orange-ish red. I'll go to a shop I have nearby to make sure I can get the right parts, I dont like ordering online unless I know for sure. Thanks again.


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## paulm12 (May 22, 2015)

quick update: I did full kit on the carb, including emulsion tubes and o-rings, needle and seat, gaskets, etc, cleaned everything well and re-installed. New fuel lines and shutoff, new primer line, fresh gas, and it started right up. I ran it for 10 minutes, let it cool a bit, re-tightened the carb and muffler bolts a bit. Put more gas in and ran it for 20 more minutes. Runs well, I adjusted idle speed to 2250 and the fast speed is at 3250. Good enough for me. 

I have new belts on order, will do before the cold. Should be good to go (until next spring when the rust gets to me and I have to paint). Thanks all for the insights. 

By the way, the Tecumseh carb tool is so worth the cost, pulls the o-rings, emulsion tubes, etc out very easily and sets them back in place without any damage. I've had it now for a few years.


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## unknown1 (Dec 13, 2015)

paulm12 said:


> quick update: I did full kit on the carb, including emulsion tubes and o-rings, needle and seat, gaskets, etc, cleaned everything well and re-installed. New fuel lines and shutoff, new primer line, fresh gas, and it started right up. I ran it for 10 minutes, let it cool a bit, re-tightened the carb and muffler bolts a bit. Put more gas in and ran it for 20 more minutes. Runs well, I adjusted idle speed to 2250 and the fast speed is at 3250. Good enough for me.
> 
> I have new belts on order, will do before the cold. Should be good to go (until next spring when the rust gets to me and I have to paint). Thanks all for the insights.
> 
> By the way, the Tecumseh carb tool is so worth the cost, pulls the o-rings, emulsion tubes, etc out very easily and sets them back in place without any damage. I've had it now for a few years.


Sweet! Good result for a non-adjustable carb... going the extra mile with the emulsion tube and orings was probably worth it. I have one of those Tecumseh tools too... use it all the time... very handy for bowl needle seats. http://www.ebay.com/itm/TEC-670377-New-GENUINE-Tecumseh-Carburetor-Seat-Tool-/191314948761


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