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

I have an old Ariens ST504 snowthrower that has served me well for many years. It has worked well even already this season Have always drained gas after the season is over, run till quit, greased, etc... so it's always been well-taken care of. It's a 5 horse...and I believe it's a Tecumseh. Looks like it was manufactured in 1978 or 1979. My problem currently is with the carb I have just thoroughly cleaned -- because the engine was trying to die when under load. So cleaning was in order. I've always had to run the machine with the choke switch on full. Anything less...even at 3/4's choke would cause the engine to start sputtering. I'm currently desperate because I live in Syracuse and after 2 days and 24+ inches of snow...and more on the way... I know no repair center will fix this quickly as they're likely up to their ears in similar requests... so I'm on my own. Obviously my careful(?) preventative maintenance did not keep me out of trouble. My question is -- After cleaning this older carb thoroughly and putting it back together the issue I now have.... and didn't before I disassembled and cleaned ....is that when I reopen the petcock under the fuel tank and gas flows back into the carb...in a matter of seconds (5-10) I then get a very small stream of gas shooting out, what I presume is a very tiny "venting hole". It's near the top and on one side of the carb. Hole is about the size of a small needle hole. Somehow after cleaning, this issue has developed. Obviously I can't even "try" to start my machine with this condition. I did a search on this forum and noticed in 2009 someone posted the exact question I have. It was at the tail end of comments about a similar Ariens carb problem. He too noted fuel squirting out a very small hole near the top of the carb assembly. Unfortunately no one responded to his question... so I'm lost. Any advice? Suggestions? thanks. Jack F

The float acts on a lever.  One side has the float, the other side of the fulcrum (pin) is a piece of flat brass that the float needle rests on.  Sometimes there is a very small wire clip that holds the float needle onto the brass plate so that it follows the movement caused by the float responding to fuel level.   Maybe someone here has an exploded view diagram of your carb that they can post.  It will help you understand where everything is and how it all works.  The small gasket on the bottom of the carb is a seal to keep fuel from dripping from the adjustment needle on the bottom of the float bowl.  If it's not leaking, don't sweat it.  

Here are your diagrams:
http://outdoorpowerinfo.com/repairs/tecumseh_carb_632334a.asp

Make sure the bowl has the step lined up with the float pin.
If you want to test the needle and seat you can hold the float up and blow in the gas line.
To test the float you have to pull it off and shake it next to your ear and listen for anything inside it.
If you hold the carb upside down, the distance between the far side of the float and the seat where the bowl goes should be 11/64" and can be tested with a drill bit.

My thanks to all of you. As a novice who'll attempt almost anything (and always have parts left over) you've put me on a course to repair success...I hope. After the mention of the needle attached to the float...I suddenly thought.."Hey, something's missing here." That part had fallen off, probably when I removed the cup on the bottom of the carb. I found it on the floor after looking around for that tiny part So sure enough...that's likely why the gas was coming out of the small hole... nothing to seal it off. I've taken your advice and removed the carb...then detached the float and set aside...then put the whole assembly in a small can I filled enough with carb cleaner to cover all the necessary areas. Surprise of surprises...didn't take long for the cleaner to start looking a little nasty. Will soak it overnight and give it a good shot of compressed air in the morning and hopefully I'll be able to come back here tomorrow and say it purrs like a kitten and no more squirting gasoline.... either that or you'll hear a story about a Syracuse man who's snowblower exploded and wiped out half the neighborhood. Thanks again... JF

Wow, that is amazing that it was the same exact problem that the Uncle had (also in Upstate NY) the same week, losing the float pin on the floor!  Too funny.  Good luck with turning off the choke next.  I'll have to be learning all this stuff soon, snowblower is brand spanking new for the moment, but I need to learn how to take care of it.

-dan

Don't forget the copper wire in every hole you find.  Also, some holes in the venturi (carburetor throat) are so small they're barely visible.  They are usually the slow speed orifice.  Look closely into the venturi to see if there's a small hole that needs cleaning.  The diagram should also help you find the fuel circuits.   If you clean the carb properly, the float level is properly adjusted and the float needle seals as it should, the carb should work fine.  Be very gentle when working with the float and float assembly.  If it's correctly adjusted, it should go right back in and work fine.  In order to prevent future carb problems, it would be wise to install a small  in line fuel filter. 

Hey Borat -

Sounds like you work on quite a OPE equipment ....
By chance, own or use a ultrasonic cleaner ?

I've been looking at a couple made by Crest.
If you know of any other brands I should be looking at, wouldn't mind some recommendations...

chefwong wrote:
I do a lot of small motor work but I can't help you with your request. 

My hobby is rebuilding/restoring/performance enhancing old two cycle Yamaha motorcycles.  I do plenty of engine/carb work and I don't rely on anything but very thin wire, WD-40 and compressed air. No sonic devices and no more miracle cure additives. 

 I own eighteen pieces of OPE, 7 motorcycles, 2  ATVs, 1 snowmobile and 3 outboard motors.   All of which I maintain myself.  I also fix friends and neighbours OPE. 

Carburetors are easy to work on provided it's not a plastic model that cannot be disassembled.   Personally, I don't subscribe to anything but the simple methods I've already mentioned.  There's no easy way to clean a carb and be sure it's done right.  It has to come apart and every fuel passage confirmed cleaned.  If you want to save yourself a world of grief, save the money you'd be spending on an ultrasonic cleaner and buy some in line fuel filters.  Best bang for the buck for any fuel system.

Can of Berrymans is my current tool of choice. Definetely try to avoid any cleaner that says it's 50 state approved.  Just looking for a xcuse to add another toy to the shelf ;-)

if the carb runs on full choke only u might be able to get away with just cleaning it as borat described which works well for a good portion of the time and sometimes thats all thats needed, although in my experiences with carbs that run very poorly is they need to be soaked in a carb solvent (not a carb spray) l use "kleen flow" this stuff works amazing its pretty prices at about $60 for a 4L jug (napa stores sell it)  but a must for doing a proper carb rebuild in my pinion, trust me u wont be disappionted. l usally soak the carbs for at least 24hrs. and l ALWAYS replace the fuel line and filter, if theres no fuel filter then add one its very important and its super cheap insurance!

it may seem like alot to spend to repair your carb but for example if a customer needs a carb rebuild that requires it to be soaked l charge $50 + the cost of the carb kit. thats just to give ya a rough idea of what shops may be charging and thats on the the cheaper end of things.

now to the carb "squirting" gas out the tiny hole that would suggest to me that the carb is flooding in some way??

Day 2 - The Saga Continues --- Am sure those of you who are experienced at successfully and quickly repairing these kind of issues will have a laugh out of this...and this may serve as a good example of the things that often can and will go wrong for the person who "thinks" he can fix it. Have decided first, that the the gasoline "squirting" out of the tiny vent hole was caused by my failure to realize that the needle(?) attached to the float that cuts off the chamber leading to the vent hole was missing. A silly error on my part. I noticed yesterday afternoon on putting everything back together (sans needle) that pushing the primer bulb caused more gas to squirt out the side. An ah ha moment. Still I hadn't realized the needle was not re-installed as it should have been... but when I pulled the starter cord it roared to life on the first pull...sounded nice and smooth...but I still had an issue of leaking gas.... and near the exhaust...so this was a no brainer. Shut down or blow up. I decided the best advice, considering the fact I always had to keep the choke at "full" in order to run without a problem... that I would do as Borat suggested (loved your movie btw ;-) and take the whole carb assembly off the machine and soak for 18-24 hours. My first mistake in this process - not removing the rubber gasket that goes between the carb assembly and the bowl. Did not realize that the I SHOULD have done this. This morning when I looked in the can where I had the carb soaking in spray carb cleaner** (perhaps a NO NO too) I sadly discovered that this rubber gasket had expanded to about 1/2 again it's original size likely as a result of being in the spray cleaner. It has since shrunk back "almost" to it's former size...but "think" I'll likely have to get a new one (hope that isn't going to be a major challenge). ...............sooooo...while I feel I've made progress...and those Syracuse snows continue to fall...I've not given up as I'm sure I can win this battle...though I have had a few "Oh noooo" moments with this effort. ....but as I write this I now find I'm having great success in shrinking that gasket back to its original size. How? I've place it under and about 3 inches away from a bright halogen desk lamp to heat and shrink. I've just got the gasket to fit in the carb bowel and it looks like this "IS" going to work. Wow ...and Whew! To all of you who have given me advice on this problem. A BIG thank you. It's surely been appreciated and I hope that my experience with this will also help someone along the way if they have a similar problem. Now, here's hoping I get this all back together and live happily ever after. Stay tuned. Jack F