B&S 675 won't start

[tlarseth]

I have a Troy Built Model 12AV566N011, with a B&S 675 Engine. I can not get it to start about 98% of the time.

I got it used 4 years ago, and it originally ran fine other than it would get random surges, but after a year it quit working and I ended up doing a lot of maintenance to it replacing items I thought could be the issue then it would start but then immediately die.

So far I have:

1. Replaced Carburetor
2. Replaced Fuel lines and filter
3. Checked fuel flow from tank and it was fine
4. Replaced Spark Plug with OEM spark plug from manufacturer
5. Replaced Air Filter
6. Deep Cleaned the outside of the mower
7. Replaced Blade

I am at my wits end trying to figure out why it is not starting. Every now and then it will start and if I shut it off to empty the bag, it won't start again for a while. Anyone have any tips or advice that might help me from having to break down and buy a new mower?

I used to do a lot of mower repair 25 years ago when I was a teenager, but haven't really touch a mower to repair until now, so I am a bit rusty, but confident I can still replace anything that needs replaced.

I have attached pictures of the engine info and mower info labels if that helps.

 

[StarTech]

2007 model but we need the model and type numbers off the engine. The layman model doesn't help us and I haven't even of a 975 series. But label shown is a 675 series.

With this it appears to be a L head (side valve) engine and with the age it is possible the valve clearance have closed up to a point that there is little compression time for the fuel to ignite.

 

[tlarseth]

2007 model but we need the model and type numbers off the engine. The layman model doesn't help us and I haven't even of a 975 series. But label shown is a 675 series.

With this it appears to be a L head (side valve) engine and with the age it is possible the valve clearance have closed up to a point that there is little compression time for the fuel to ignite.

Is this something that would be feasible to fix, or would it be more prudent to just buy a new mower due to age?

I have also edited the OP to reflect 675 instead of 975, I mistyped the info, thanks for pointing it out

 

[Ocean909]

Check to make sure the choke is operating correctly.

 

[Tiger Small Engine]

Is this something that would be feasible to fix, or would it be more prudent to just buy a new mower due to age?

I have also edited the OP to reflect 675 instead of 975, I mistyped the info, thanks for pointing it out

As long as you have good compression, it is repairable. The cheapest push mower at Walmart is $255.00 plus tax. Use the 50% of original cost of equipment as a guide to how much to spend for repair. Do it yourself will be very affordable. A shop repairing it will most likely be better than buying a newer mower.

 

[SeniorCitizen]

Lets go back to the basics rather than spend more money .
We know it has spark (at the correct time ) , air and gas because it is running part time but not starting when hot .
Possibly some of the shop owners here can direct you a item that heat may cause no start .

Fuel is a simple test ( when it won't start ) by dropping about half of a eye dropper / 1/4 teaspoon of gas in the top of carburetor with no choke .