Hey!!!! Dave will you where out playing with the goats yesterday I fixed the grand daughter's push mower. It was raining here as well, so I did some shop work.
To bring the guys up to speed on this old issue. My grand daughter has a push mower that has a B&S engine on it. She had it over speed a few weeks ago. She brought it to me to fix. The original problem was the little plastic air vane was broken so the governor could not work. I ordered a new one an installed it and then the thing would not start. Replaced the coil, new plug, checked and adjusted the valves, cleaned the carb. Still no fire. Checked it and it had good bright blue spark. Good compression too. It would not even run putting fuel into the plug hole. I posted on here for some ideas on the problem.
Solution: I marked TDC on the flywheel screen and made a mark on the shroud to line the flywheel mark up with. I then hooked my timing light up on it with a battery providing power to the timing light. I then cranked the mower over. It was firing about 45 degrees after top dead center. How could it do that??? The flywheel key was fine. I finally took a flywheel of another B&S motor I had here. Installed it and the mower started first pull. What the he!!. I took it back off and put the original back on it. Nothing still firing way late. So I put the other flywheel back on it and finished adjusting the carb. Grand Daughter came and got it this morning after church.
After lunch today I got to thinking about how the flywheel could be bad after being over revved. I got a magnifying glass out and looked it over real close. Two of the little fins in the magnet where gone. In bright light and with the magnifying glass you could see where they had been in the flywheel. The break point was shiny but back in the magnet 1/4 inch or so. The magnet was a little weaker then. I guess that changed the magnetic field enough to make it fire late.
First time I ever seen or heard of that happening. I broke the darn thing into pieces as it looked new and I did not want to get it mixed up with a good one. I should have kept it around to mess with some one with. LOL
So I got something productive done while Dave II was goat training. LMAO
To bring the guys up to speed on this old issue. My grand daughter has a push mower that has a B&S engine on it. She had it over speed a few weeks ago. She brought it to me to fix. The original problem was the little plastic air vane was broken so the governor could not work. I ordered a new one an installed it and then the thing would not start. Replaced the coil, new plug, checked and adjusted the valves, cleaned the carb. Still no fire. Checked it and it had good bright blue spark. Good compression too. It would not even run putting fuel into the plug hole. I posted on here for some ideas on the problem.
Solution: I marked TDC on the flywheel screen and made a mark on the shroud to line the flywheel mark up with. I then hooked my timing light up on it with a battery providing power to the timing light. I then cranked the mower over. It was firing about 45 degrees after top dead center. How could it do that??? The flywheel key was fine. I finally took a flywheel of another B&S motor I had here. Installed it and the mower started first pull. What the he!!. I took it back off and put the original back on it. Nothing still firing way late. So I put the other flywheel back on it and finished adjusting the carb. Grand Daughter came and got it this morning after church.
After lunch today I got to thinking about how the flywheel could be bad after being over revved. I got a magnifying glass out and looked it over real close. Two of the little fins in the magnet where gone. In bright light and with the magnifying glass you could see where they had been in the flywheel. The break point was shiny but back in the magnet 1/4 inch or so. The magnet was a little weaker then. I guess that changed the magnetic field enough to make it fire late.
First time I ever seen or heard of that happening. I broke the darn thing into pieces as it looked new and I did not want to get it mixed up with a good one. I should have kept it around to mess with some one with. LOL
So I got something productive done while Dave II was goat training. LMAO
