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

I noticed fuel leaking out of carberator intake when engine is stopped on my snow thrower. Prior to this I replaced the needle and seat as a tune up measure. Is it possible to put the seat in backwards? I did notice that the rubber seat is groved on one side and flat on the other. I took it apart again and checked the float. I blew in the fuel line and moved the float up and it seems to seal off well. But when i put it back together it still leaks fuel. Where else can the fuel be coming from?  Thanks

If you can shut the fuel off when manually moving the float and it won't shut off when installed in the machine I think the float level needs to be adjusted. In addition make sure the step in the bowl is oriented properly. You should also check the level of oil in the crankcase. If the dip stick shows overfull drain the machine and refill with 26oz. of oil. The overfull condition is gas leaking into the crankcase and contaminating the oil. Don't run it if there is gas in the oil.

Marc 

The side with groove goes up into the carb so the needle hits the non-groove side.

Another check is to shake the float to insure there is no liquid inside from a leak. Gas in the float might go unnoticed because the amount of gas inside might be small, does not have a lot of weight, and during disassembly you usually take it off and put it down so don't notice it. For example if the leak is on the bottom there will be a lot of gas in the float. If the leak is high on a side it won't have much gas inside.

When you take a float off it's wet. You set it down and continue to work. Float leaks I've had were from tiny holes. After the initial removal the gas on the float dried up. When I shook the float and found gas inside the gas did not drip out because the hole was so small. Shaking caused the gas to ooze out over the float around the hole but not form a droplet.

Just as a check I sank two floats with gas inside into a clear glass with a weight on top. No bubbles rose up. Maybe the holes were so small the water membrane was too much to overcome. It might be that a leak might be enhanced with vibration from the motor running. Since starting to check for this all the time I've found 2 floats that had gas inside since this summer but with no wetness on the bowl surface once they dried on the bench.

This summer I had a pesky intermittent leak on a lawnmower. It's possible to imagine a situation where if the leak is in the right spot it might be just on the edge of causing a problem. It's also possible to imagine a situation with vibration that a leaky float could gain or loose gas. If a leak were high on the side and getting gas in during running it might loose gas from evaporation when stopped given the long idle time of yard tools.
David

Thanks for that info> Ididnt think of checking for fuel in the crank case. I did put the seat in backwards I hope thats my problem. I didnt hear anything sloshing around when i shook the float but when i pull it apart again ill try submurging the float in container of fuel for a while and take a closer look. I can adjust float by bending the float tab. Im assuming the float should be at an equal horizontal distance from carb all around when it closes the fuel entry?   LA

LA55-Use an 11/64" drill bit to set the float level. The step on the bowl goes on the fuel inlet side of the carb body (ref. section 2 p4 of the Tecumseh Mechanics Handbook 3-10h.p.)

David- Good job on the porous float!! I always forget that-

Marc 

i put the seat on backwards on the last one i did,and i had the same problem,flipped it around and presto,no leak.

trouts2 wrote:

About the float, that happened once in my Van needle was always at EMPTY and the tank was full, I had to dismantle the tank and got the sending unit out and replce the float, but in a carb its different it floods :)

Good luck

LA

l had a still have the exact problem on on my hm80, l've done everthing l think?, l replaced float needle and seat and tried reversing the seat and that didnt work and l read on another site that the open end of spring that attaches the needle to the float has to face towards the choke side (front of engine) of the carb, apperantly tecumseh had a recall on this causing the carb to flood, l tried this but my carb still leaks, l was also told when some people remove the seat they us a pick or screw which can scratch the side while removing the seat and fuel can leak around the seat. l use compressed air with a small hose on it to blow it out. sometimes u can turn the carb upside down with the bowl off and blow in it get a leak (like a cracked carb) but with mine you can blow as hard as can and wont leak one bit. these carb are very basic and this has stumped me, any how l've had my cusion look at it he's a licesed mechanic and he couldnt figure it out, so l took it to the local small engine shop and they couldnt get it to stop leaking they told me i need a new carb but couldnt tell me whats wrong with mine, so l havent touched it for a couple of months so l'm curios to what your gonna find keep us posted.

l almost forgot l replaced the fuel hose going from the tank to the carb and added a inline filter to make sure no dirt or little piecs of hose are were getting stuck under the needle. GOOD LUCK!

Hey  Guys I turned the seat so the grove went towards the carb and replaced the float (apx. $6.00) and the problem is solved.  I submersed old float in gas all night and it seems to be fine. oh well.  If you look at the diagram of carb you will see the open end of the needle retainer clip facing the choke side of the carb. Good point niper99. Sounds to me you may have a cracked housing. I was fearing that because if the needle dont stop the gas there seems to be no other option. If yours is flooding while its running and cant controle it with the high idle setting, you may have to replace carb. But if it is only leaking like mine was when its not running you can put an in line shut off valve for when its sitting idle. Thank you all for the great support. This is an awsume site. Ill be bringing more problems here im sure.

I'm happy that  stumbled upon ths thread. My stepson gave me his old Ariens ST824 (model 924050 w/ Tecumseh 8HP). It stopped running so he went out and bought a new snowblower. Being the tinkerer that I am, I did some troubleshooting and determined that it was the carb that was faulty.  So I went to my local Ariens dealer and purchased a rebuild kit for the carb. After I rebuilt it, I installed it back on the motor. As soon as I opened the gas valve, gas started pouring out of the primer outlet. I was sure that I did everything right so I took it apart again but didn't see anything wrong. I Googled my problem - low and behold, I found this thread. I'm happy to say that it turned out to be that I put the grooved side of the needle seal towards the bowl. I flipped it around and seated it using the shaft of a drill bit, put it all back together, and voila! No more gas leaking and it started right up! Thanks guys, I appreciate the tip.

Now I need to tweak the adjustments on the carb. It runs fine at near full throttle with the choke 3/4 on (which I'm sure is not right) and stalls out at mid to low rpms. What's your advice fine tuning the carb? I did one and a half turns from closed on the screw at the bottom of the bowl. Should I tweak this one out some more - maybe 2 turns?

Your advice would be greatly appreciated.

 

turn it a 1/8 of a turn at a time,on the side it should be 1 turn out

If you cant correct the high speed adj check the main jet ,thats the brass hollow bolt that holds the bowl on. Mine had two horizontal holes(jets) in it and the small one was cloged Its so small I didnt even see it the first time I cleaned the carborator.Be carefull not to enlarge this hole (jet)I used the fine wire in side of a trash bag twist tie.

Hey there hcd724 beware that if the engine is getting wet when your using the machine that could cause rough running . Shield off the motor and that will solve that problem. What i did with my carberator was take it apart and blow out every hole with carb cleaner. if you look in the carb from the choke side you will see 2 small holes on the right. make sure the are clear. blow in the needle valve areas. when its back together back of the main jet needle 1.5 turns (bottom side needle. ) Back off idle adjustment needle on the (side of carb )1.5 turns. this should let the motor start. Let it warm up turn the idle needle  in  until engine changes sound an starts running rough then turn it back untill it starts doing the same thing . Then turn it back in to the center point.   Now exellerate engine High speed and do the same with the bottom fast idle needle screw. Worked for me. I was having to run mine with choke 3/4 on too before taking it all apart and adjusting. Also I removed the blower housing and cleaned the ignition coil and re adjusted gap. Starts on the first pull.