Mower wouldn't start, "rebuilt" carb and worked.... again doesn't...

So at the end of last season my 10641 20-Inch Briggs & Stratton 675 Series Gas Powered RWD would not start. I ended up cleaning the carb and it would work, after a couple weeks sitting it wouldn't. So then I bout a rebuild kit for the carb and replaced the gaskets, cleaned it real well, and it worked great... until it didn't (I also used seafoam and soaked it in the spark plug "chamber" which seemed to help). So the start of this season it works fine, after a couple months it doesnt start.

Last week I soaked the spark plug chamber in seafoam again and it seemed to help. I was able to mow my lawn. Today... won't start. Rather than soak the spark plug trick again (seemed like a bandaid) I opened the carb to clean it... but it "looked" pretty damn good. What might be the issue? Is this mower just a piece of junk not meant to last? I probably had it for 7 years now. Did the yearly oil change, sharpened the blade every 2-3 years, I felt like I took pretty good care of it for what was mild small residential use about 1/3 acre lot I would guess).

Curveball..
Unfortunately, I was just screwing a screw that connects to the shaft throttle and that part of the carb housing literally broke off. A new carb appears to be $50 and I'm not sure it's even worth it if this mower is done for anyways.

Thank you for the help.

(attached a photo of the breakage)

To clarify, I suppose at this point my question is 2-fold:
Is this mower worth fixing?
What went wrong so I don't do it again (I thought mowers should last considerably longer)?

You have a very great mower and engine.......... You had it 7 years and that is great use from a mower.. I do 2 oil changes a year and sharpen my blades every month........ Or every 3 weeks.... Like an older friend of mine from here in town always said, I like to cut my grass, not break it.

I don't use any seafoam for a quick fix, or anything like that...... Only way to get a carb cleaned well is to take it off and then take it apart and soak it in a ultrasonic cleaner or a good carb acid..... Then put a kit in it ..... That's what I do all the time....

Where you at here in Louisiana ?????

I live in the south, so basically I would mow once per week or every 2 weeks but not during Winter months.

You say 7 years is good... does that mean I basically used it and it's not worth repairing? (Would surprise me; I thought they lasted 10+ years.)

Also, when you say "kit" do you mean carb kits like just the washers and gaskets? (That's what I did at the end of last season which worked for half a year at best -- and mostly winter months of non-use.)

To me the part which broke off is for the air vane mount for the auto choke. If properly maintained at 7 years that engine is a teenager and worth fixing. To me it sounds like when you rebuilt the carb, you didn’t replace the float needle and seat, plus make sure the float level was set properly. If I am correct, this should have solved your problem.

Actually I work on engines that are way older than that...... Your mower is a good one and it is worth repairing......

Sorry for the late response Mon Ami....... I have been selling Sugar Town watermelons all day and then trying to look up parts for a few customers that showed up today at TSC.....

Your kit is the 498260 which is about 13 bux retail... It comes with everything you need..... 2 bowl gaskets 2 air filter box gaskets. A jet, a spring and a O ring that you don't need... ETC ETC........

Do you have a primer bulb on your air box or the EZ start Auto choke.... ???????

Those 2 carbs take the same kit but they use the different bowl gaskets and air box gasket.........

When you said screwing a bolt to the shaft throttle, I have to agree with Rivets. That is the air vane hold down bolt for the auto choke..... You can save money by just squirting gas in the carb, start it up then screw the filter cover back on.... When the engine is warm it should start back up.....

Let us know Mon Ami ~!~!

Rivets said:

To me the part which broke off is for the air vane mount for the auto choke. If properly maintained at 7 years that engine is a teenager and worth fixing. To me it sounds like when you rebuilt the carb, you didn’t replace the float needle and seat, plus make sure the float level was set properly. If I am correct, this should have solved your problem.

Click to expand...

The carb kit included a new needle and the little plug you mentioned. I pressed it in with a punch, if this is what were talking about.

However, setting the float level sounds like something i could have messed up as there wasn't anything special i did. Be that as it may, the mower did work for some time after i did the carb cleaning.

That lil plug you are referring to is the seat for the needle...... It has a groove on one side...... That groove goes down into the carb body........... The flat side will be UP facing the needle point........ It has to be seated all the way down... A T 25 Torx bit works well for that... The longer 2 inch bit I mean. Not the lil 1 inch one.........

When you clean a carb like we do then all you have is a bare carb, NO welch plug either in it, the lil round disc in the kit...... If it's a kit like I said earlier....

IF your carb wasn't too bad of a shape. you don't have to take it out ........ It's a vent passage in a way..... You can spray carb cleaner thru it and that does a pretty good job on those style carbs........

I deal with those carbs often in my shop over here........

Let us know Mon Ami ~!~!

Thanks for the help everyone. I had run into some stuff and got distracted. But basically, as long as I fire the mower up twice a week, it's working now. I'm just going to buy a new carb next year before the season starts and hope the mower is otherwise as good as you all say it is! That's reassuring though.

lawndarts said:

Thanks for the help everyone. I had run into some stuff and got distracted. But basically, as long as I fire the mower up twice a week, it's working now. I'm just going to buy a new carb next year before the season starts and hope the mower is otherwise as good as you all say it is! That's reassuring though.

Click to expand...

Thanks for the response Darts........... Where are you at in Louisiana in my area ??? I am just north of Crowley.... I can help you with a new carb OEM of course.... We have a local Briggs dealership here in town........

Let me know Mon Ami ~!~!

Boudreaux In Eunice La. said:

Thanks for the response Darts........... Where are you at in Louisiana in my area ??? I am just north of Crowley.... I can help you with a new carb OEM of course.... We have a local Briggs dealership here in town........

Let me know Mon Ami ~!~!

Click to expand...

I appreciate the help and offer... Im nearer to the SETX/LA border however. So a bit away. I'll just pick up a carb online somewhere it's not a very old mower so I imagine parts are out there!