Hello All,

I have a 3.5hp on an Ariens snowblower. It has the typical side draft carb and gravity feed fuel supply. When I turn on the gas it flows into the bowl. The minute I open the needle valve on the bottom of the bowl gas leaks out the venturi of the carb. When I close the valve it stops. The float and needle seem to be operating properly. Ideas?? Rebuild or missing part??

Thanks

It sounds like you either have a worn out needle seat or a float that's full of fuel. In my opinion, you probably need to rebuild it.

yeah sounds like its the seat.

Thanks to the two of you. Rebuild is what I will do. I did notice the needle sticking a bit.

yeah especially if its of considerable age or used alot it's better on your part to rebuild for two reasons, it'll stop your problems, and second it'll give it more years of long use. plus if done your self you save alot of $$ because you can go to a small engine shop and get the kit cheap but get them to do it and all they see is $$$ signs. and your welcome, I'm glad to help when ever i can.

Ok, I put a new needle and seat in along with the bottom mixture screw assembly and the idle mixture screw. I also installed new plugs and cleaned everything out. The carb still leaks out the venturi when I open the bottom mixture screw. I am going to change the float setting so it is level with the carb base and see what that does.

Any ideas???

That didn't do it either. Oh, ya it is a Tecumsuh 3.5hp.

make sure the float well floats, if it's sinking it will do that.

what needle valve did you use there is 2 different ones ,one that has a small round rubber looking seat usually green , that you have to use with the right needle valve that has to be put in the seat the right way it will have a ring arround one side that should go away from ya ; the other is just the needle it will look kinda dark on the end that goes in the seat , shake the float up close to your ear and listen for noise inside the float , also the small wire clip that holds the needle to the float has to be put on the right way or sometimes it will cause the needle to stay off the seat , have had it happen
,,,,,,for sure check the seat if you can see the ring its in there wrong turn it over

Before i would rebuild the carb i would take it apart n use carb cleaner to clean out the seat. I have saved engins like that that get stuck just by cleaning them. when others would just rebuild them. try this first if it dosent work than rebuild it. saves ya a little green

yeah sometimes old trusty carb cleaner can get em going when the carbs still on, would i recommend when you get it back going, use fuel stabilizer. running em dry lets the seals etc. dry out before thier time. and it don't gum up

yeah dry seals = cracks cracks = leaks = leaks = probs = probs = go to hobby talk n ask for help.

yeah dry seals = cracks cracks = leaks = leaks = probs = probs = go to hobby talk n ask for help.
yep, been running stabilizer through one i had that used gaslines, those lasted over 6 years compared to the 3 or 4 you might get by running the fuel out