Lawnmower blade retaining nut - clockwise or anti?

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#2184188 20-Feb-2019 10:07

In the off position the throttle should earth the coil but that gets out of adjustment. The mower doesn't have to strart, just a kickback could take a finger off.

Years ago I had an old Triumph 650. One of my sisters put her hand on the kickstart and asking "Is this how you start it?" gave it a half hearted push down a few inches. The bike answered by starting an idling. Never did that for me. Some of the cars that stop on idle leave a cylinder on compression just needing a spark to kick it into action.

I stop my old mowers by taking the plug lead off and leave them like that.

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#2184194 20-Feb-2019 10:12

Bung:I stop my old mowers by taking the plug lead off and leave them like that.

So you get a few little whacks for fun?

Bung

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#2184241 20-Feb-2019 11:18

Too old be caught like that. Normally wear Showa gloves.
Learnt my lesson on Suzuki 2 stroke that fouled plug. Sometimes you could clear it by holding plug cap just above sparkplug, or you could if your gloves weren't damp. Had about 5 secs folded over tank before turning off.

Jase2985

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#2184587 21-Feb-2019 07:58

I just used a boot to talk my lead off

traderstu

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#2184685 21-Feb-2019 09:26

geekIT:

EDIT: Can I lay the machine on its side to work on the blade without draining the oil and petrol?

General rule of thumb is to flip the mower so that the plug points upwards. Should be no issues with the oil. I would run it out of petrol before doing the job.

tdgeek

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#2184687 21-Feb-2019 09:33

traderstu:

geekIT:

EDIT: Can I lay the machine on its side to work on the blade without draining the oil and petrol?

General rule of thumb is to flip the mower so that the plug points upwards. Should be no issues with the oil. I would run it out of petrol before doing the job.

Also, will need to place something to jam the blade, stop it turning. My one apparently has a hole in the blade and body for that. 4x2 also works.

geekIT

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#2184769 21-Feb-2019 11:52

Heads-up on my original question.

First, I omitted the reason I wanted to remove the blade: excessive vibration (IMHO) of the machine on its first start after purchasing it. I thought I'd remove the blade and see how it ran without it.

I'm aware this 4 stroke B&S was never going to be as smooth running as my old electric B&D, but I've had petrol mowers in the past and I thought the degree of vibration was outside the acceptable range.

So, I used it for about 10 minutes and stopped it. That's all the running it's had in the 4-5 weeks since its purchase. (I'm re-laying all my lawns and they're now bare dirt)

Anyway, yesterday I visited the Mitre10 store where I bought the mower, mainly to let the store owner know about the vibration. No complaints there - he immediately said to bring it in so they could check it. During the conversation, I asked him about the thread on the blade retaining bolt - left or right?

He initially said he had no idea, but after a bit of thought, added, 'Probably left-hand thread'.

Interesting.

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#2184775 21-Feb-2019 12:04

Yeah, too confusing, whats a left hand thread? When you turn the bolt does the top of your hand go left or the bottom??? :-)

If you look at the blade and imagine it turning based on what side the cutting edge is on, that's the same rotation as undoing the bolt

Vibration is odd on a new mower. It might actually be normal, maybe normal at the upper end of normal, but to you its harsh compared the the electric mower. New mower blade should not be unbalanced. You can unbalance a blade by sharpening unevenly (try and do the same number of file or grinder passes to edge blade). Check all engine to body bolts as well

Bung

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#2184783 21-Feb-2019 12:22

So we all have all the details.

What is the model of mower and what type of blade is it?

If it is a blade holder with swinging blade tips it is possible that one tip is stuck not fully extended, that will unbalance the mower. A fixed blade would need obvious damage to unbalance it after just 10 mins running.

The mower probably wouldn't run well without a blade as it could act as part of the flywheel.

If it is a Briggs & Stratton engine the bolt will be a normal 3/8 x 11/4" UNF not lh thread.

Ge0rge

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#2184822 21-Feb-2019 13:45

tdgeek:
Yeah, too confusing, whats a left hand thread? When you turn the bolt does the top of your hand go left or the bottom??? :-)

When you are looking at the fastner from above, think "Lefty-Loosey, Righty-Tighty" for a conventional (or right hand) thread.

By "above", I mean that undoing the fastner will cause it to move towards you, not away. Imagine your car - when you sit facing the wheel and undo the wheel nuts (or bolts in the case of some vehicles), the fastner moves towards you as you turn it left to loosen it - Lefty-Loosey ;)

(unless you've got a particular variant of truck, which has right hand threads on one side of the vehicle and left hand threads on the other - unfortunately Righty-Loosey doesn't have the same ring to it!)

tdgeek

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#2184828 21-Feb-2019 13:54

Ge0rge:
tdgeek:

Yeah, too confusing, whats a left hand thread? When you turn the bolt does the top of your hand go left or the bottom??? :-)

When you are looking at the fastner from above, think "Lefty-Loosey, Righty-Tighty" for a conventional (or right hand) thread.

By "above", I mean that undoing the fastner will cause it to move towards you, not away. Imagine your car - when you sit facing the wheel and undo the wheel nuts (or bolts in the case of some vehicles), the fastner moves towards you as you turn it left to loosen it - Lefty-Loosey ;)

(unless you've got a particular variant of truck, which has right hand threads on one side of the vehicle and left hand threads on the other - unfortunately Righty-Loosey doesn't have the same ring to it!)

:-) I will be perpendicular to the wheel!

tripper1000

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#2184921 21-Feb-2019 16:03

My Brigs and Stratton has conventional/normal thread.

IME they are either so tight you just about round them off getting them loose, or they come loose by them selves every 6 months - no happy middle ground. There is a good chance they put lock-tight on the threads when assembling it.

Make sure that you are using a proper socket/ring spanner. Don't try it with an open end-er or an adjustable, and don't try it with a budget tool.

tdgeek

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#2184931 21-Feb-2019 16:21

tripper1000:
My Brigs and Stratton has conventional/normal thread.

IME they are either so tight you just about round them off getting them loose, or they come loose by them selves every 6 months - no happy middle ground. There is a good chance they put lock-tight on the threads when assembling it.

Make sure that you are using a proper socket/ring spanner. Don't try it with an open end-er or an adjustable, and don't try it with a budget tool.

Good advice. CRC is worth a spray too. I took my blade off every now wand then to sharpen so that was fine. First time I gave the ring spammer a few minor jolts with a hammer to help break any seal or rust

geekIT

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#2185538 22-Feb-2019 19:04

Bung: So we all have all the details.

What is the model of mower and what type of blade is it?

If it is a blade holder with swinging blade tips it is possible that one tip is stuck not fully extended, that will unbalance the mower. A fixed blade would need obvious damage to unbalance it after just 10 mins running.

The mower probably wouldn't run well without a blade as it could act as part of the flywheel.

If it is a Briggs & Stratton engine the bolt will be a normal 3/8 x 11/4" UNF not lh thread.

Okay, the machine is branded on the (red) shroud 'Vinaro 350ST'. There's a plastic plaque on the front labeled 'MORRISON'

The engine is a B&S 500E, 140 CC OHV. Made in USA.

I took a look at the blade, and yes, it has add-on tips.

You say 'swinging' blade tips - does that mean these bits should be rotating freely? Because they don't. One is pretty much locked in place, the other moves if I twist it.

Incidentally, the bolt head exactly fits a 14mm socket. I tried again to undo it as I would a conventional rh thread , but it wouldn't move.

Shame these things don't have a locking button like most skilsaws.

I'll find a way tomorrow :-)

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Bung

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#2185555 22-Feb-2019 19:50

geekIT
I took a look at the blade, and yes, it has add-on tips.

You say 'swinging' blade tips - does that mean these bits should be rotating freely? Because they don't. One is pretty much locked in place, the other moves if I twist it.

Incidentally, the bolt head exactly fits a 14mm socket. I tried again to undo it as I would a conventional rh thread , but it wouldn't move.

Shame these things don't have a locking button like most skilsaws.

I'll find a way tomorrow :-)

The blade tips must be able to extend straight out as the blade rotates. If one is stuck folded that would easily explain the vibration.

9/16" is 14.3mm so a 14mm socket will be a snug fit. The bolt is 3/8 UNF not metric.

I usually jam the blade with a piece of wood.

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