ok ij ust bough a light blue briggs. when I touch the top of the spark plug wire it gives my hand a very strong jolt. I could not get the motor to run so I pulled the plug out and saw that it was making no spark at all so I put a different plug that was on another briggs that was running 5 minuets before I took the plug out. I put it in the 5 hp spark plug cap and still no visible spark and motor wont start. Like I said coil jolts my hand but neither of the plugs make spark which one of the 2 is confirmed to be a good working plug. what is the problem here? the magneto seems to be in good working shape due to the fact of how strong it zaps my hand. Someone please help!
5 HP Flathead spark help?
- Thread starter Mini_Biker_Aleks
- Start date
- Tags flathead spark
Make sure the plug is grounding out when you pull the motor over. Do this by ensuring that the plug is connected to the coil, then hold a rubber part of the coil wire (or spark plug boot), and hold the plug against a head-bolt (you could also rest the plug on a head-bolt without holding it). Some other things you could do include rubbing the flywheel magnet with a piece of sandpaper or a wire brush to get whatever rust my be on there, off. Also, as suggested above, clean the underside of the coil (may be rusty). If you haven't already, remove the flywheel and the points and condenser cover and clean and re-gap the condenser. Also make sure that the little plunger like thing is moving up and down smoothly. Do this by rotating the crankshaft and keeping an eye on the points and condenser. If the small spring loaded arm moves up and down the plunger is free and working. Make sure to set the correct gap of everything when putting it back together. This is super simple if you have a "feeler gauge set" and a standard business card.
For memory the gap spec. for between the condenser and the arm is .010. Gapping the condenser is fiddly and may take some trial and error.
To gap the coil, simply loosen the coil bolts, place a business card underneath the coil, hold the card and rotate the flywheel until the magnets are underneath the coil. The coil should sit down automatically. Once it does, tighten the bolts and remove the card. May take a few goes to get it right.
Not sure if you already know this stuff, it's just good stuff to know and try if you have not already.
-Jack
For memory the gap spec. for between the condenser and the arm is .010. Gapping the condenser is fiddly and may take some trial and error.
To gap the coil, simply loosen the coil bolts, place a business card underneath the coil, hold the card and rotate the flywheel until the magnets are underneath the coil. The coil should sit down automatically. Once it does, tighten the bolts and remove the card. May take a few goes to get it right.
Not sure if you already know this stuff, it's just good stuff to know and try if you have not already.
-Jack
Jolting your hand is not a good indicator that the magneto is working properly. It takes a lot more energy for the spark to jump the air gap in the plug and far more energy for the spark to jump the gap under pressure. Even if the plug sparks outside of the engine it doesn't mean it will spark when installed and under compression.