Briggs and Stratton flywheel nut removal

[Cajun power]

if it starts and runs and there is no other performance problems other than just a hard pull start...then it's probably going to be either and overfilled oil...or there is some trash wrapped around the mower blades/spindle. I am assuming there is no blade engagement switch (like a PTO) on this push mower yes. so when you are starting it, you are also cranking the blades over. I would look there...it's probably why the blade got loosened....just an idea.

so two things: check the oil fill. make sure it's not overtopped. Then engine off, check to see if there isn't some trash wrapped around the blade and shaft.

noting: when tilting an engine to one side to get under the deck, make sure you let it sit for about 15-30 minutes before you start it. Allows time for the oil to drain back out of areas where it can cause starting problems and performance issues and foul plugs as a result. fuel can also end up in places like the air filter and out of the fuel cap, potentially causing fire hazards...I think there is a specific side of the mower to tilt when doing an oil change for most push mowers. Check that out in the manual. It will help reduce the chance of problems.

 

[Fish]

If the blade is off or loose, it will jerk the cord out of your grip like that. Pushmowers have an aluminimun flywheel, and need the mass/weight of the blade. If that same engine were on a pressure washer or the like, the flywheel would be cast iron.

 

[benson1980]

Thanks again all for the assistance. I didn't know the slightly loose blade (which has definitely got worse over the last few weeks) would potentially cause these symptoms as well so despite the new mower arriving the other day I would still quite like to fix this one. Therefore I've looked again at the blade itself and the parts catalogue here:

https://www.sparepartsworld.co.uk/product.php?sn=SPARE_PLM5121

There's an upper and lower pressing plate, which I assume are designed to hold the blade in place once everything tightened. They are cheap enough so I've ordered a set and will see how I get on.

 

[benson1980]

if it starts and runs and there is no other performance problems other than just a hard pull start...then it's probably going to be either and overfilled oil...or there is some trash wrapped around the mower blades/spindle. I am assuming there is no blade engagement switch (like a PTO) on this push mower yes. so when you are starting it, you are also cranking the blades over. I would look there...it's probably why the blade got loosened....just an idea.

so two things: check the oil fill. make sure it's not overtopped. Then engine off, check to see if there isn't some trash wrapped around the blade and shaft.

noting: when tilting an engine to one side to get under the deck, make sure you let it sit for about 15-30 minutes before you start it. Allows time for the oil to drain back out of areas where it can cause starting problems and performance issues and foul plugs as a result. fuel can also end up in places like the air filter and out of the fuel cap, potentially causing fire hazards...I think there is a specific side of the mower to tilt when doing an oil change for most push mowers. Check that out in the manual. It will help reduce the chance of problems.

Thanks I did check around the shaft and all looks ok. And definitely not overfilled with oil.

 

[STEVES]

if it starts and runs and there is no other performance problems other than just a hard pull start...then it's probably going to be either and overfilled oil...or there is some trash wrapped around the mower blades/spindle. I am assuming there is no blade engagement switch (like a PTO) on this push mower yes. so when you are starting it, you are also cranking the blades over. I would look there...it's probably why the blade got loosened....just an idea.

so two things: check the oil fill. make sure it's not overtopped. Then engine off, check to see if there isn't some trash wrapped around the blade and shaft.

noting: when tilting an engine to one side to get under the deck, make sure you let it sit for about 15-30 minutes before you start it. Allows time for the oil to drain back out of areas where it can cause starting problems and performance issues and foul plugs as a result. fuel can also end up in places like the air filter and out of the fuel cap, potentially causing fire hazards...I think there is a specific side of the mower to tilt when doing an oil change for most push mowers. Check that out in the manual. It will help reduce the chance of problems.

Carburetor up on top, oil gets into vent tube and ends up in carb if it is on the down side.

 

[Tommy Mckeown]

Hold on! You said the blade rotates on the engine shaft? You should understand that the blade IS your flywheel! It's where the inertia energy is stored when you first crank or pull the cord. I'm going to say that getting the blade tight on the crankshaft is the FIRST problem you need to fix. Once the blade is tight on the shaft the mower will probably start.

 

[Tommy Mckeown]

If you need proof, Take the blade off of a perfectly running mower and try to start it.

 

[benson1980]

Hold on! You said the blade rotates on the engine shaft? You should understand that the blade IS your flywheel! It's where the inertia energy is stored when you first crank or pull the cord. I'm going to say that getting the blade tight on the crankshaft is the FIRST problem you need to fix. Once the blade is tight on the shaft the mower will probably start.

Yep I understand that now. Definitely know a lot more about how my mower works thanks to the advice on here. Hopefully when these new parts arrive it will sort a lot of the issues I’d been having with it.

 

[midavis]

…I have tried the strap wrench method and as you can see this has just caused the fins to shear off as I tightened around them. I have therefore bought a replacement secondhand flywheel off Ebay. This repair is not going well...

For what it’s worth, if this can ever be of future help to anyone:

I was faced with the same situation on my 2012 Toro Turfmaster with its Kawasaki FJ180V engine. It has a very similar style pulley and I didn’t have their special expensive Bracket Holder tool to hold the flywheel and remove bolt. It was easy to fashion one from a random cut-off piece of 2" diameter iron pipe and fastening some bolts to it. (I first ground down its threading for a snug fit.) Then it was just a matter of gripping the pipe with a pipe wrench and putting your socket/extension on the bolt down inside.

 

[benson1980]

So...to update on this issue. I fitted the replacement pressing plates and straight away the blade held firm, and now it appears to be running like a dream! Obviously slightly annoying I pulled the trigger and bought a new one now, but we have lots of grass to mow and a spare/old mower isn't necessarily a bad thing...

The other problem I have now is that the brake kill switch attached to the lever doesn't stop the engine so I'm having to pull the ignition coil if I want to shut it off. Obviously something to do with replacing the flywheel but whether it had it's day and that was the final tipping point perhaps? Anyway, the brake pad seems to still make contact with the flywheel so that is my next project to do some research on and sort.