I have a pressure washer with what I think is a Tecumseh engine.
Failed to start and there was no spark. Ordered a new coil as they ae pretty cheap these days and i didn't want to mess about.
Stll no spark. This is a simple engine. No points or condenser, just a cut off wire. With the wire disconnect still no joy.
Cleaned up the ground path., nope.
I was messing about spinning the flywheel by hand (no gas at this point) and noticed that i got a spark when I spun the flywheel CCW and not CW.
I refitted the old coil and got the same result!
Of course the engine runs CW.
Has anyboybody seen this or have any ideas?
I know the magnet (which feels strong) has a north south bias but it's never been touched and is fixed on the flywheel.
Beats me.
(New coil, new sparkplug, no cutout wire, clean ground)
The Hall effect triggers are polarity sensitive.
It is not unheard of for a magnet to reverse polarity if stored under the correct conditions which is why new ones come with a keeper plate on them.
I was under the impression that the coil was just a coil with low and high voltage coils. Hall effect transistors are low voltage and are triggered by magnetic field. do you have a typical circuit diagram?
If the Magnet has flipped is it possible to replace it? I can't see any being sold unless as part of a new flywheel.
Peter
The Atom module or a Magnatron or any other "points eliminator " is a Hall effect trigger.
Google them and you will find circuit diagrams from the very simple to the extremely complicated with reducing amounts of retardation to effect an advance of the spark.
because they work on the voltage generated in a coil and because the wavefront will start off either negative or positive depending upon the polarity of the magnets the triggers are sensitive to the polarity of the magnets .
When the triggers were first introduced they had resistors transistos & diodes soldered onto a board and were external items like you have there.
Now days the same circuitary can be burned into a chip, small enough to be emedded into the potting mix so the external units were replaced with internal ones and $ 5.00 coils became $ 40.00 modules
I am no B & S expert in any way shape nor form but have found out that on some of the older points engines, you can fit a modern "module" back to front & it will work
#7
StarTech
Need engine numbers to see what your setup is. and also need to which coil you ordered.
I can confirm that the magnet on my engine has the S pole on the left using a compass.
Looking at the diagram flipping the coil will not help. It will not change the direction of charge.
I think i need a new magnet (flywheel)
Peter
#14
StarTech
Actually it does. On old Briggs engines we had to have magnets re-polarize due coil manufacturing changes to use the newer Magnetron coils that were previously points systems. This was because the old system were positive ground systems and the newer Magnetrons are negative ground systems. Some point systems also were negative ground this is why universal ignitors (Atom modules) that can be setup for negative or position were developed.
On Briggs the positive ground point versions usually were the cast iron engine and Brigg negative ground points versions are the aluminum crankcase engines.
I have seen my share of the left hand engine nightmares. Bought a used west bend Kart engine mounted it on a racing kart pulled on rope till I bled , was not happy with the seller and he came to start it for me and said it is mounted on the wrong side of the Kart, he wrapped the rope the other way and it ran first pull. The old Detroit buss engine from gray hound buss fits in a semi tractor and when we started it and went out it had 13 reverse gears, moved the injector pump to the other side of top dead center and swapped starter which turned other way and it was fine. Rebuilt a ford six cylinder for a pneumatic tank trailer and used a normal oil pump and it should have been the other way and it locked up in 4 minutes, My cub lo boy with the C60 international engine must be backwards, the pto turns counter clockwise and the belly mounted deck say Woods R meaning Rear mount but turns the right way under it. I think the wrong way is common on marine application. Good time to ask Bert which way does your tolite water turn when flushed? ours is clockwise
#16
Hammermechanicman
LoBoy? 154, 185 or 184? I have a 184 with a 3160A mower.
Not a numbered series Lo Boy, It is like a Standard Cub but the rear axle is rotated forward a 1/4 turn to lower 8 inches and the front spindles are 8 inches shorter then a standard, exhaust is under not up. So it ends up 8 inches lower and shorter from the factory. I understand the 184 was the most powerfull cub they made
#18
Hammermechanicman
You have the steering on the side?
Yeah, the 184 is the cadillac. Automotive clutch on engine not trans. Separate starter and alternator no starter generator. Electric PTO clutch. Popup pistons and bigger Zenith carb.
