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

I don't understand the need to soak a carb overnight in expensive carb cleaner if all passages, jets and orifices will be physically cleaned with copper wire, blown through with WD-40 and then compressed air.  If I soak a carb in anything, it's usually just inexpensive paint thinners (Varsol) and the reason I do that is to get grit and grime off the exterior of the carb.   I wouldn't spend $60.00/gal on  carb cleaner.  Not when the carb can be cleaned for next to nothing. 

Yo  JackFlan:

 I applaud and encourage your willingness to fix your OPE.   If obtainable, having relevant diagrams and "how to" information available prior to doing the job will go a long way to make things easier.

Personally, I get great satisfaction from fixing stuff.  The absolute best reward is fixing things without having to buy anything.  I love to fabricate and innovate.  I like to improve the machine, not just fix it.   Anyone can do remove and replace mechanics and sometimes, you have no choice but to buy a replacement  part.  I do a great deal of maintenance and repair out at my camp in the bush.  It's 60 miles from civilization and lots of dirt road.  When something breaks out there, it's a looooong  way to the hardware store.   I'd say that 90% of the time I can make a fix with what I have laying around. 

Many people think they have cleaned their carb by pulling the float bow and flushing it out or letting it sit overnight in carb cleaner.  It's a start but the carb may not be not certainly cleaned.  Jets and needles must be pulled, inspected and cleaned.  The orifices and galleries that feed the jets must be know to be clean.  Air passages must also be known to be clean.  Due to the minuscule size of some orifices, it's difficult to establish that passages are clean but I look for WD-40 spraying  out the holes for my first clue.  Then I use the right amount of compressed air to blow through them to confirm that they are clear.  I use a pointed rubber tipped fitting on my blow gun which allows me to press it into air and fuel entry holes, then  I hold my finger near the exit orifice to confirm air is passing through.  I don't use too much pressure for testing because it's easier to control the air source.  I've never met a carb I couldn't fix and I've seen a few of them.

 

SUCCESS!!! 3 Cheers to ALL of you! This 30 year+ Ariens 5hp snowthrower is now running like new! Started on the first pull and now literally diving into the snow. Loooook out!!! I have done as recommended in previous posts...and ran into a few issues along the way and noted above, but in addition to the good cleaning I've also now installed a new gas line and added an inline filter. A BIG THANK YOU from snowy Syracuse to all of you who offered your assistance. Excellent help. Regards... Jack F

while in 95% of carbs u cant clean every passage way its impossible, the high speed circuits can usally be cleaned with a piece of wire or what not, but its near impossible to clean the low idle circuit, and lm speaking from experience on what works from experience,  l would say l rebuild give or take 100-150 carbs a year, and with that said not every carb needs to be soaked but l would say that 75% of carbs benifit greatly from soaking them and some of them thats the only way to clean them. 

what l have found after soaking a carb thats adjustable is the carb setting change back to the standard 1.5 turn high / 1.25 low and they run perfect. so for example yesterday l rebuild a carb on a 1977 tecumseh motor 10 hp, when it came in it would only run on 3/4 choke and it wouldn't idle at all. the high was set at 2.75 turns out and the low 3.5. if l tried to change the setting at all the machine would even run. now the only thing l did was soak the carb for 24 hrs and install a new needle and seat and carb bowl gasket, when i assemble it back on the motor i set the high to 1.5 and the low to 1.25 and the machine runs and blows snow 2ft deep without missing a beat with no further adjustment.

and yes l would agree $60 for a 4L jug of carb clean is expensive but it works, and l can use that 4L jug for a hole year probally longer if l wanted but l buy new stuff once every a year. and l charge $50 + parts for a carb rebuild so its pays for its self on the first repair.

I've never had a carb that I couldn't clean with wire, WD-40 and compressed air.   Every carb that I've cleaned ran perfectly afterward also.  People can choose which method they prefer to use.  However, if it can be done with minimal to no expense, why spend money unnecessarily. 

I've never had a carb that I couldn't clean with wire, WD-40 and compressed air.   Every carb that I've cleaned ran perfectly afterward also.  People can choose which method they prefer to use.  However, if it can be done with minimal to no expense, why spend money unnecessarily. 

lm not completely in disagreement with what u said, l just think that with as many carbs as l do every year l come across more carbs that are in pretty rough shape, and for me soaking them works the best, but everybodys got there own way of doing things and whatever works and gets the job done is all that counts.