Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

Briggs and Stratton 4.5 HP push mower carb question


buggersnot's Avatar
Member

Join Date: Jun 2014
Posts: 3
ME

06-18-14, 11:19 AM   #1  
Briggs and Stratton 4.5 HP push mower carb question

I inherited this Craftsman 21" 4.5 HP b&S lawnmower presented with a total lack of maintenance. I ordered parts from Repairclinic.com using the serial # and model # of the engine. I replaced the Spark plug ,the air cleaner element, the coil , the carb which came with diaphragm and gasket and a thimble screen and a spring. I was not aware that there was a spring there when I removed the carb but found that there was a broken spring under the carb. I need to know where this spring goes? The problem I am having is I can not prime the carb using the red push bulb. If I put gas in the carb it will start and run when the gas tank runs out and it is refilled the mower starts with one pull no need to add gas to carb.

 
Sponsored Links
geogrubb's Avatar
Member

Join Date: Jun 2006
Posts: 2,333
MO

06-18-14, 12:39 PM   #2  
The spring sets on top of the diaphgram, I will post the instructions for changing the diaphgram..:

You need to install a new diaphram kit, it is Briggs part # 795083 or old # 495770 also Lowe's has a kit #5083 which has the same parts.
Here we go:

Remove air cleaner, there are 2 bolts that hold things together, one on the front of the tank 3/8" and one into the block 1/2", remove these bolts, now "slowly" slide the carb/tank off the intake tube and breather tube, now tilt the tank in to release the throttle linkage and waalaa the carb/tank is removed. Check the intake tube to see if the O ring seal and plastic retainer are still on the intake tube, if so remove them and re-install them into the carb. Remove the 5 screws from the carb/tank remove carb(don't loose the spring) now spray all holes, cracks and crevases in both the carb and tank surface with brake parts cleaner, remove the main screen(looks like a thimble), now with a small screwdriver pry out the main jet(carefully) and clean it, check the O ring on the main jet for damage, if it is damaged it must be replaced, reinstall the jet, it can be difficult some times to get it to snap back in place(I use the rounded end of a screwdriver handle). Remove and clean the fuel pickup stem(not necessary if the fuel tank was clean). Clean any junk/rust from the tank. Install the diaphram on the tank then the gasket(no goo or sealer) now carefully replace the carb(the spring will try to misalign the diaphram), tighten all screws a little at a time so as not to crimp the diaphram until they are all tight. Install the carb/tank in reverse order and you are done. If I missed something one of the real mechanics will correct me. Have a good one. Geo

 
buggersnot's Avatar
Member

Join Date: Jun 2014
Posts: 3
ME

06-18-14, 05:14 PM   #3  
A new diaphragm and gasket came with the brand new carb I bought which I installed . My question now is is there a place on the carb that the spring sets on to hold it in place when I install the carb.

 
geogrubb's Avatar
Member

Join Date: Jun 2006
Posts: 2,333
MO

06-18-14, 07:12 PM   #4  
The spring goes over the post near the bottom of the photo below. Have a good one. Geo


 
buggersnot's Avatar
Member

Join Date: Jun 2014
Posts: 3
ME

06-19-14, 09:52 AM   #5  
Thank You for your help I thought that is where it should go but was not sure.

 
Search this Thread