Sharping blade on Lawnmower

The Reader

Hi all

This morning went about my task of sharping the blade on my 16" Harry lawnmower. Then reattached my blade and went to start my lawnmower I suddenly got a tremendous kickback on my efforts to start it and then found that the blade on the lawnmower had become completely detached from the mower and fell on the ground underneath the mower. Would appreciate the views as to why this happened on the mower all I did was take the blade off and sharpen it and screwed it back on. Thanks for attention.

Mr321

What age is the lawnmower? Did it shear the pin/coupler when the blade fell off?

The Reader

I have the Harry lawnmower a good many years possibly in excess of 15 years as I have only a small area of lawn to cut. No visibly damage that I could see ,it simply unscrewed itself from its support and dropped on the ground.

Lewis_Benson

Sounds like you didn't tighten the bolt enough.

Mr321

Yea either not tightend up enough or maybe the threads on the bolt/nut have corroded somewhat the last number of years. Best replace the bolt/nut then and get cutting

monseiur

This is a fairly serious health & safety issue. Try a nyloc nut, it's basically a lock nut with a nylon insert (must have the same tread / be same size etc. as current one) or else fit a spring washer under nut. If thread on bolt itself is sheared it must be replaced

The Reader

Thank you all for your contributions. Yes I agree with Monseiur it is a health and safety issue hence the reason I have decommissioned my Harry and going about to replace it. I shared my experience with my local lawnmower repair center and while he didn't examine the mower his initial observations were that its a valve issue in the motor. There you go ?