Tiny Spark

[John_RI 0]

Looking for the first snow of the year tomorrow and the landlord seems to have lost most of it's spark. Doesn't have enough to jump the gap of the plug or the gap of a briggs spark tester. If I lay the wire on the top of the head and crank I do see a weak spark there. I've cleaned the points and found no improvement. Any ideas ? ? Thanks, John

[cojo92 1]

Same happended to my & hp briggs too...well kinda...My dad fixed it for me and he said the coil needed to be replaced...maybe yours needs to be replaced too. Or it could be shorting out!

[D-17_Dave 11]

You may need to clean the magnets on the flywheel or even may have a weak coil. But double check your points. I've cleaned sets of points several times with little effect then finally get through the crud built up on the points and it fire real well.

[HubbardRA 12]

I take my points off the engine then separate the two pieces. I use sandpaper and polish each of the contacts until it is smooth, square, and shiny all the way across. I have found that if I don't take this extra time to do this, I may still have a weak or even no spark. Also, after re-assembling the points onto the engine, close them, then use a sheet of notebook or typing paper and slide it back and forth between the contacts to polish them and remove any sanding residue from the previous cleaning. After this cleaning, then gap the points and things should be good-to-go.

[John_RI 0]

Thanks for the suggestions. I feel pretty dumb - I should have been doing this a month ago but I was still waiting for the last of the leaves to fall. Before they all fell, it got cold so I thought I'd wait for a warm day to put on the winter rig. Well, here I am with no spark and a prediction of 5" - 10" tomorrow. I'll work a bit harder on the points, but for now I pushed the Landlord a little further into the barn and brought in the 'running' 725. Never plowed with it before. The Landlord has lights and a hydro lift which is nice with the plow. The 725 also has 9.5" tires which presented a struggle fitting the chains to, but they went with some words. All that's left is the plow which shouldn't be a problem. Thanks again for the help. John

[meck 0]

Recently, I had a similar experience. Everything (coil, points, etc.) seemed to individually check out but fire was too weak to run well. It was driving me crazy. Turned out it was the ground cable connection from the battery to the frame. While I was cleaning it up, I also moved the connection from where it had been on the frame to a bolt on the engine itself. Strong spark. Good running. Problem solved 'til the next one. Good luck.

[olcowhand 0]

Condensor....may be the problem. When condensors go, the spark is still regular, but very weak.

[John_RI 0]

I finally pulled the engine & blower cover. No surprise, the mice had packed the area around the coil to the point where I don't think they could have fit one more blade of grass (well, maybe one). I now think the coil may be shorted. Could someone tell me what the resistance should be across the primary on a 12 hp cast iron briggs? Thanks, John