Backfire is the name of the game

[sgkent]

when did this problem begin?

 

[MikeH62]

Thanks for the replies everyone. I checked the ignition module and everything is connected soundly. I do remember replacing that module many years ago but I don’t know if it could be the cause of backfiring or not. In fact at some time or another I’ve replaced a number of parts back when I was using it a lot but the 2001 mower has been sitting idle now for over 5 years due to health reasons and now I’m just attempting to resurrect it. I’m aware that like me, it’s getting old but heck, it’s a Lawnboy. My first one lasted over 20 years under very heavy use. They are great little mowers if you ask me.

A couple of you mentioned the backfiring or popping sounds being different sometimes and that’s interesting because I had even thought this backfire sounded ‘sharper’ or ‘poppier’ than a normal exhaust backfire, but its really hard to say. Someone suggested running it in the dark to see if any evidence and I’m going to do that when I can. I’ll try to establish where it’s coming from.

Thanks again for the suggestions and ideas so far, I plan to consider them all. I operate at a snails pace these days so it might take me awhile but I’ll report progress as I can.
Blessings to you all!

Make sure that when you mounted the carb the mating surface on both sides were very clean and the gasket wasn't deformed. It could be as simple as it's sucking air at the gasket causing the popping.

 

[Oddjob]

Taryl of Taryl Fixes All had a live feed video recently where he described the problems he has had with NGK plugs. Start and die, won’t start and making popping noises. He had a box of ten and they all were junk. He used a Champion and voila, fixed.

 

[kjonxx]

I have a Lawnboy SilverPro Series 10324 with the 6.5 hp Duraforce. I installed a new carburetor, checked the exhaust ports (which were surprisingly clean), installed a new NGK spark plug gapped at .035, air filter is clean and everything is in good order. Or so it seems. This thing starts up usually first or second pull and runs fairly good, with one exception - it backfires constantly. It has enough power that I could probably mow with it but the backfiring is a total nuisance. Not to mention it’s an indication that something is not right and there’s the chance I might do more harm by running it.

Does anyone know of something I can try? Thank you so much.

Check the key if it started after you hit something