# 1971 Ariens Sno-Thro primer/choke thing?



## FlamingSpaghetti (Jan 8, 2018)

I have a 1971-ish Ariens Sno-Thro which has a 7HP Tecumseh and appears to be a 24" clearing. There is this spring-loaded black knob that says "Primer" on it and I have no clue as to how it even works. All it appears to do is choke the carburetor. Does anyone have any input on this old style primer?


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## classiccat (Mar 1, 2014)

Yep, rather than forcing air into the float bowl with a primer bulb (_which in turn forces fuel up through the emulsion tube and into the venturi_), holding the button in during the intake stroke creates a vacuum in the throttle body (_which in turn sucks fuel up the emulsion tube_).

It actually works quite well. Make sure the mating surfaces are clean.

To be kind to these old ignitions, ground the ignition (throttle in "off" position) when giving it the primer pull (_you don't have to pull hard either_)...then release the prime-button, move to half throttle for the starting pull.


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## FlamingSpaghetti (Jan 8, 2018)

classiccat said:


> Yep, rather than forcing air into the float bowl with a primer bulb (_which in turn forces fuel up through the emulsion tube and into the venturi_), holding the button in during the intake stroke creates a vacuum in the throttle body (_which in turn sucks fuel up the emulsion tube_).
> 
> It actually works quite well. Make sure the mating surfaces are clean.
> 
> To be kind to these old ignitions, ground the ignition (throttle in "off" position) when giving it the primer pull (_you don't have to pull hard either_)...then release the prime-button, move to half throttle for the starting pull.


Thanks for this valuable information. This tells me that the spring on my primer is on the wrong side and should be on the outside of the heater box, is this correct?


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## cranman (Jan 23, 2016)

Should be on the outside....yes......


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## classiccat (Mar 1, 2014)

FlamingSpaghetti said:


> Thanks for this valuable information. This tells me that the spring on my primer is on the wrong side and should be on the outside of the heater box, is this correct?


Not a problem!

Correct, spring on the outside of the bracket.

Here's a shot of mine (prior to refurb) with the heater-box removed:


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## Kiss4aFrog (Nov 3, 2013)

He shows how to do it about a minute in.


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## scrappy (Dec 7, 2014)

Agree! 
How ever, for some reason my self and dad removed the primer on his '67 tecumseh. It has always started with a few pulls. It could also be the machine was always in a attached garage. So never below 0 degree cold starts. A shot of ether won't hurt either. Any ways that primer is long gone. I would buy one just to put it back to original.


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## classiccat (Mar 1, 2014)

scrappy said:


> Agree!
> How ever, for some reason my self and dad removed the primer on his '67 tecumseh. It has always started with a few pulls. It could also be the machine was always in a attached garage. So never below 0 degree cold starts. A shot of ether won't hurt either. Any ways that primer is long gone. I would buy one just to put it back to original.


here ya go brother scrappy. 

referenced my '71 H50

choke plate
https://www.ebay.com/itm/Tecumseh-3...024585&hash=item284c2a52dd:g:gRoAAOSwKXdaTsjR

spring (reference only... so you can grab one from the parts bin instead of getting robbed blind)
https://www.ebay.com/itm/Tecumseh-P...3cAAOSw9GhYb7ho:sc:USPSFirstClass!12306!US!-1

bracket
https://www.ebay.com/itm/Tecumseh-C...080515?hash=item3d54b3e403:g:5qMAAOSwnVhaSljk

primer knob
https://www.ebay.com/itm/NEW-Tecums...K8AAOSwmudZ~5CX:sc:USPSFirstClass!12306!US!-1


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## FearlessFront (Aug 18, 2016)

Its missing the round air filter mount bracket, which would of been their since its a 10000 series and would have been readily available to swap to a summer engine for attachments.
It would have originally looked like the engine in this photo, which was my original Tecumseh from my 1971 Ariens 10000 series. (heater box removed to show how it looks under their).
Fourth photo after photos of primer with air filter mount plate shows engine in summer mode with mower attachment.
Last photo in winter mode round bracket on behind heater box.
The decal on the heater box (often worn off or faded from age and weather) as well as in the engines operators manual would have said at 10 degree and below use the primer by pushing and holding it and turning over the engine 3 times slowly to prime. Those primers really aren't needed unless its that cold, they start very well just on choke up above 10 degrees and a shot of starting fluid also would work just as well/better than the old spring loaded primer.


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## classiccat (Mar 1, 2014)

FearlessFront said:


> Its missing the round air filter mount bracket, which would of been their since its a 10000 series and would have been readily available to swap to a summer engine for attachments.
> It would have originally looked like the engine in this photo, which was my original Tecumseh from my 1971 Ariens 10000 series. (heater box removed to show how it looks under their).
> Fourth photo after photos of primer with air filter mount plate shows engine in summer mode with mower attachment.
> Last photo in winter mode round bracket on behind heater box.
> The decal on the heater box (often worn off or faded from age and weather) as well as in the engines operators manual would have said at 10 degree and below use the primer by pushing and holding it and turning over the engine 3 times slowly to prime. Those primers really aren't needed unless its that cold, they start very well just on choke up above 10 degrees and a shot of starting fluid also would work just as well/better than the old spring loaded primer.


Is the filter mount plate needed if you only have a hot-box (winter use)?

Man, that's one sweet setup FF! How does it cut?


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## FearlessFront (Aug 18, 2016)

No its not needed if your just going to use it as a snowblower. Most snowblowers did not come with the air filter mount bracket on behind the heat plate. Tecumseh engines that were on Ariens 10000 series machines came with them so you could readily swap from winter to summer with other attachments. The actual air filter and cover would have came with the summer attachment when you purchased it. 
The nice thing about all Tecumseh "Snow King" engines is they were all readily able to be swapped from a winter engine to a summer engine (all season). Most engines now do not have that capability.
I'm glad my engine had it because originally I never planned to use the mower attachment but than I got one and it already had the plate to switch over and I had an air filter cover and air filter sitting around, so I was ready to swap. 
I have since removed and sold that old engine and now I have a Predator which I just remove the air filter out of the box in the winter and put back on in the spring when I switch it back to the mower.


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## scrappy (Dec 7, 2014)

classiccat said:


> here ya go brother scrappy.
> 
> referenced my '71 H50
> 
> ...


Crazy prices. I put a bid in, see what happens. Thanks!


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## sscotsman (Dec 8, 2010)

scrappy said:


> Crazy prices. I put a bid in, see what happens. Thanks!


For $25 you could probably find a complete non-running snowblower, with engine, with ALL the parts! 
of course, that takes some looking..I understand ebay is easier.  (I use ebay myself for parts like this)

Scot


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## scrappy (Dec 7, 2014)

sscotsman said:


> For $25 you could probably find a complete non-running snowblower, with engine, with ALL the parts!
> of course, that takes some looking..I understand ebay is easier.  (I use ebay myself for parts like this)
> 
> Scot


I know Scot!! Funny thing is, don't even need it. Starts fine without it. Just trying to make it look original as possible.


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