6.75hp Briggs runs fine until really warm...

[threefivezero]

I have a Troy-Bilt self propelled mower with a 6.75hp Briggs engine. I bought it used off Craigslist and it was pretty rough looking. Something had fallen on it and broken the carb off at the base.

I fixed that, and cleaned the carb thoroughly, and put a new spark plug in it. I had to remove the magneto to fix the carb tube, so I regapped it at 010.

The thing now runs great when it's cold. If I mow with it for 20-30 minutes, though, it will suddenly sputter and die, and may or may not start again until it completely cools off. In any case, even if it does start back up while warm, it only runs a minute or so before stalling again.

I can mow my lawn in 30 minutes on a good day, so I can live with it, but for example right now I got behind and it's over grown, so it'll take me 3 days to get it back in shape if I can only mow 20 minutes at a time.

I'm thinking it's the coil? What else could it be?

 

[lakeviewpe]

It does sound like your coil is bad or going bad. Another thing you can check is, when it starts sputtering and dying, take off the fuel cap. If it doesn't die then and keeps running, you may need a fuel cap due to it not venting properly.

 

[benski]

It does sound like your coil is bad or going bad. Another thing you can check is, when it starts sputtering and dying, take off the fuel cap. If it doesn't die then and keeps running, you may need a fuel cap due to it not venting properly.

Good catch. Those would be two great places to start.:thumbsup:

 

[threefivezero]

Thanks guys!

I tried the gas cap today, I hadn't thought of that... but it didn't make any difference. Even if I take the cap off, and prime the carb again, it still won't start until it cools off for a while.

So I ordered a coil... $20. This brings my grand total to $90 I've invested in this used mower for the entire 2011 mowing season. I can live with that!

I'll report back when I get it installed, and see how it runs!

 

[threefivezero]

*also, just for fun, over the past month, this mower has been affectionately referred to as the "Lawn Mower of Eternal Frustration"...

 

[threefivezero]

Happy to report that the Lawn Mower of Eternal Frustration just ran for 35+ minutes without a single stumble. New coil seems to have done it!

Thanks for your help!!!

 

[lakeviewpe]

Great, that was an easy fix and you didn't have to spend another $100 on another used mower or $400 for a decent new mower.