5 hp snowblower problem

475wls1

Forum Newbie
Joined
Jan 7, 2018
Threads
1
Messages
1
Hello, I have a craftsman snow blower with a 5 hp b&s engine. The engine will not run but a minute or two before it quits. I can re-prime the engine and it will start, but again, only run for a couple minuites. I have replaced the gas line and priming hose to the carburetor and even replaced the carburetor last year. Same problem. Thanks in advance, Mark
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
55
Messages
14,681
To me it sounds like you are not getting a good flow of fuel in the carb. If it came into the shop with this problem this is the steps I would follow.

1. Remove the fuel line from the carb and make sure you have a good steady flow of fuel from the tank to the carb.
2. Reattach the fuel line and start the engine. As soon as the engine starts to sputter, push the primer bulb and see if you can keep the engine running. If you can’t keep it running, you will have to go back to step 1, as you are not getting enough fuel to the carb.
3. If you can keep it running with the primer, I would remove the carb and give it a good cleaning and replace the float needle and seat. I follow this procedure.

Needle and seat replacement.


Remove the carb, and then remove the float bowl. Check the float bowl jet (which is the bowl screw) and make sure the jets both horizontal and vertical are clean and open. Tip the carb upside down and remove the float pin and float with needle attached. Look in the float needle passage and you should see the red float seat at the bottom of the passage. This is where a #5 crotchet hook would come in handy as you need to remove this seat. If you have no hook, but compressed air, you can blow through the fuel inlet and try to pop the seat out. Put your thumb over the passage to prevent the seat from flying who knows where. No air or hook try bending a stiff paper clip to dig the seat out.


I would either give the carb a good 24 hour soaking or have it ultrasonically cleaned at this time.


With the seat out clean the passage way with carb cleaner. Now you must find a drill bit slightly smaller than the passage way, to be used to press in the new seat. Apply a very, very small amount of a very light lube to the new seat. 3-1 oil or lighter, to help seat it better. Carefully insert the new seat in the passage way with the rings on the seat down toward the carb body. Slowly and carefully force the seat down with the back end of the drill bit. Once it is seated, check to see that it did not flip and the rings are up. Next check to make sure that the float does not have any liquid in it. If it does, replace. If everything looks correct, attach the new needle to the float and install with the float pin centered. It everything is correct, the float should seat level to the carb body, when looking at it upside down. If everything looks good reattach the float bowl, making sure that both the bowl gasket and the nut gasket seal properly. Reinstall on the engine and test unit. Remember to have patience and take your time. Good luck, but I don't think you'll need it.


PS: On the side of some Tecumseh carbs you will find a plastic cover. Under this cover will be an idle jet. Remove it and check to see that the jet is open both horizontally and vertically. You should be able to push the old float needle wire through the vertical opening.

4. After rebuilding the carb, install and try again. Let us know what happens if you try this.

 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
If this is a gravity fed engine ( engine numbers really help you getting better advice ) then check the fuel flow.
Good chance the supply from the tank is insufficient to maintain the engine.
 
Top