Crankshaft bolts/nuts on various models

ILENGINE said:

The fuel solenoid requires a minimum of 9v to operate, and the regulator/rectifier requires 10v to close the internal switch to allow power to reach the battery. Some engines are set up for the regulator to output power without a battery for various operations( wide area mower) so it is doable, which would also power the fuel solenoid.

You can get some mowers to run without a battery, but if you momentarily get the voltage to drop below that magic number, say kicking in the pto, the charge system will open the micro switch, and kill output from the regulator, and therefore shut down the engine because no power is reaching the solenoid.

The fuel solenoid job is to help prevent the BANG it will no stop a carb from overflowing and flooding the engine and crankcase with gas. Now there are others systems out there that shut off the fuel flow to the carb Some are electric, some work on engine cranking vacuum pulses.

Click to expand...

bertsmobile1 said:

It is EPA regulations to prevent fuel being sucked into the carb & blown out unburned in the dozen or so revolutions between when you turn off the the engine & it stops spinning.
Hard to believe I know just think of Mr Pencildick from the original Ghostbusters.

AS previously stated mufflers run red not to after burn any unburned fuel during use then when you turn it off, air enters the muffler which has fuel vapours in there and a red hot ignition source so when the air:fuel ratio becomes correct for burning at atmospheric pressure it goes bang

Click to expand...

turbofiat124 said:

First of all, can someone tell me why B&S is no longer installing recoil starters on lawnmowers? At least on 17.5 HP and up models. This is very handy when you discover that the battery has bit the dust after the winter and you really need to mow your yard that particular day before going back to work the following day or you're like me and you're too cheap (or frustrated) to buy a new battery every other year.

When did Briggs and Stratton went from using nuts to bolts on the crankshaft/flywheel?

Reason I ask is I have this nutty idea to made a rope starter for one of my lawnmowers. Most likely my MTD 17.5 B&S engine. I also have a 21 hp B&S Husqvarna. I'd like to do both.

I have a 14hp B&S circa 2000 that threw a rod through the block. It looks like the rod bearing nuts were not properly torqued or had Locktite from the factory and vibrated loose which sent the rod through the block. The engine was less than 5 years old.

This engine is on a shelf in my storage building and I'm going to have to move some stuff to get to it and pull the cooling shroud off to find out.

The plan is to:

1) Drill a hole through the side of a socket and the crankshaft bolt for a roll pin or cotter pin.
2) Up through the socket will be a 1/2" carriage bolt threads facing upwards. Maybe a few flat washers to take up any slack in the depth of the socket.
3) Use a pulley that uses a square keystock to keep from spinning
4) Grind a slot in the end of the carriage bolt for the keystock.
5) Cut a groove at an angle for the knot on the end of a rope.

This winter I pulled my batteries off my mowers and hooked them to trickle chargers. Hoping I can get more than 1 to 2 years out of these horribly cheap lawnmower batteries everybody sells.

As long as I have the strength and ability to pull start a lawnmower engine, I'd just soon do that as to keep spending money on these junk batteries.

I think my Interstate battery made it one season. The Husky battery from Lowes (I think) made it 2 years before it bit the dust.

The battery on that same Snapper went bad after a year and I just pulled started it for 10 years until I sold it.

Click to expand...

Boobala said:

I think you're thinking SOMETHING along these lines ... ???

......View attachment 31885

Click to expand...