To save money, i always drill two holes (with my small drill press) in the boss where the pins would have been, tap it with M8 thread and screw in two quality bolts. In worst case i have welded a blade on with two tag welds. I appreciate your channel. It's informative with a wide range of subjects. And i love your thick Yorkshire accent. Nick
So the boss could just be tapped off - should be that loose! So I was so keen to see how Mower Man would replace the boss, but the video ended before that.
Never had the blade adapter keyway cause issues with timing. The flywheel one does massively, but as long as the blade is tight this one shouldn't matter. Hayters and Hondas dont have keyed blade adapters and they run fine.
Sound advice mowerman we all buy and sell mowers, but they do have to be safe. When you mentioned about having a brew two minutes in I promptly stopped the video, made myself one and carried on watching haha. ATB. Rob.
Isn't it the woodruff key under the flywheel that affects the timing? I think the one you show in the video is just to hold the boss in place so the belt doesn't spin it on the crank?
Andy K I think that's correct but i've had some mowers nearly rip my arm off if the blade isn't sat correctly on the pins. I'm sure the top one effects timing more but wanted to show how to replace. Thanks though
I can't get the boss off that has the pins sheard, tried with a puller just can't shift it. put a nut in the end. All I achieved was breaking the flange part that the blade contacts with. Looks like I am going to have to take the engine off for better access. Turned into a right job. Managed to get the old boss off, by sawing it then using a puller it eventually came off. Put the new one on now and used copper grease on the shaft, so won't have that trouble in the future.
Managed to replace one of these a few years ago,them promptly hit another tree root :^o I have a similar mountfield but the deck is now far to rusted to safely use.The JCB mower I have have had sitting outside for 12 years since getting the mountfield is in better condition! Currently doing an engine swap and was chuffed to find the Mountfield engine sits happily in the JCB deck,and simply swapped the top half of the handles over. See if I can swap the Boss' over as well :^) Smaller JCB mower with the 150cc Mountfield engine looks like a hotrod too haha
The ones I have the real fun with are the round steel blade adapters. I've got one that the 3 jaw puller, blowtorch , penetrating oil and shocking it with a hammer has had no effect on it so far.
Hi, I’m having trouble sourcing a blade boss for my mountfield hp470 mower, have tried everywhere I could think of and returned a couple that just did not fit. The dimensions I require are The bore through the middle - 10mm The shaft diameter 22.2mm The overall length 65mm The distance between the blade location pins 43mm (52mm centres) Have you any idea where I can source one (I’m near Huddersfield) Thanks.
Thanks for this. I've just repaired my Mountfield SP53H with the help of your video. Unfortunately the band must have come off, as it doesn't self propel anymore. Well, that's a job for tomorrow. One question though: I'm sure I'd read that you should only ever lean these mowers backwards, rather than sideways, to access underneath. Something about flooding and damaging some component? But clearly doing a job like this would be very difficult like that. So, is there any truth in it?
I put the mower on a stand tilted right back, and colapse the handle, so don't have to tilt it side ways. My other mower a honda can be tilted on it side but only one side, and not the other side. so the oil doesn't run into the air filter.
@@verybigkittens7550 ah ok, so the H in my model number indicates a Honda motor. I guess then the same night apply. I'll look it up for next time I need to access underneath.
@@MowerMan I'd have been very surprised if you didn't know. Good to watch. My mountfield SP530 blade boss sheared & broke today, which is what caused me to search. A new boss has what looks like slightly off square locator pins, whereas holes in the blade are round ? Stay safe.
To save money, i always drill two holes (with my small drill press) in the boss where the pins would have been, tap it with M8 thread and screw in two quality bolts. In worst case i have welded a blade on with two tag welds.
I appreciate your channel. It's informative with a wide range of subjects.
And i love your thick Yorkshire accent.
Nick
Nick Hoeppermans Thanks!
is it yorkshire not a manchester accent. If it is yorkshire must be Leeds.
So the boss could just be tapped off - should be that loose! So I was so keen to see how Mower Man would replace the boss, but the video ended before that.
Never had the blade adapter keyway cause issues with timing. The flywheel one does massively, but as long as the blade is tight this one shouldn't matter. Hayters and Hondas dont have keyed blade adapters and they run fine.
Sound advice mowerman we all buy and sell mowers, but they do have to be safe. When you mentioned about having a brew two minutes in I promptly stopped the video, made myself one and carried on watching haha. ATB. Rob.
Great video. This explains my kickback. Blade hit something hard. Cheers. MM.
Michael Goad to help
Isn't it the woodruff key under the flywheel that affects the timing? I think the one you show in the video is just to hold the boss in place so the belt doesn't spin it on the crank?
Andy K I think that's correct but i've had some mowers nearly rip my arm off if the blade isn't sat correctly on the pins. I'm sure the top one effects timing more but wanted to show how to replace. Thanks though
Big difference between people who make videos on how to do something and people who are professionals at doing those things.
I can't get the boss off that has the pins sheard, tried with a puller just can't shift it. put a nut in the end. All I achieved was breaking the flange part that the blade contacts with. Looks like I am going to have to take the engine off for better access. Turned into a right job. Managed to get the old boss off, by sawing it then using a puller it eventually came off. Put the new one on now and used copper grease on the shaft, so won't have that trouble in the future.
Great video well explained, cheers 👍
Managed to replace one of these a few years ago,them promptly hit another tree root :^o
I have a similar mountfield but the deck is now far to rusted to safely use.The JCB mower I have have had sitting outside for 12 years since getting the mountfield is in better condition!
Currently doing an engine swap and was chuffed to find the Mountfield engine sits happily in the JCB deck,and simply swapped the top half of the handles over.
See if I can swap the Boss' over as well :^)
Smaller JCB mower with the 150cc Mountfield engine looks like a hotrod too haha
Helpful video, thanks!
looking at the pins they are only a bit of steel rod! you could knock the pins out and replace them, just put a touch of locktite on them,
Is the shaft with the thread in it and the key way slot, the bottom of the cam shaft on the mountfield sp 454.
The ones I have the real fun with are the round steel blade adapters. I've got one that the 3 jaw puller, blowtorch , penetrating oil and shocking it with a hammer has had no effect on it so far.
Simon Welch I feel your pain! Occasionally I take them to the local car garage and they undo them with an impact socket for me!
It definitely does not affect the timing if the blade boss keyway moves. There is a key on the crankshaft inside the engine that controls that.
Do i really need 2 pins for the blade?
My blade bolt has been rounded and I am struggling to get it off. Any suggestions?
Where do you bulk buy your Briggs & Stratton keyway and what is the size? Thanks in advance
Hi, I’m having trouble sourcing a blade boss for my mountfield hp470 mower, have tried everywhere I could think of and returned a couple that just did not fit.
The dimensions I require are
The bore through the middle - 10mm
The shaft diameter 22.2mm
The overall length 65mm
The distance between the blade location pins 43mm (52mm centres)
Have you any idea where I can source one (I’m near Huddersfield)
Thanks.
you could jam some wood up against the blade and the side next time.
mogsy briggs I've treated myself to an impact tool now!
Thanks for this. I've just repaired my Mountfield SP53H with the help of your video. Unfortunately the band must have come off, as it doesn't self propel anymore. Well, that's a job for tomorrow.
One question though: I'm sure I'd read that you should only ever lean these mowers backwards, rather than sideways, to access underneath. Something about flooding and damaging some component? But clearly doing a job like this would be very difficult like that. So, is there any truth in it?
I put the mower on a stand tilted right back, and colapse the handle, so don't have to tilt it side ways. My other mower a honda can be tilted on it side but only one side, and not the other side. so the oil doesn't run into the air filter.
@@verybigkittens7550 ah ok, so the H in my model number indicates a Honda motor. I guess then the same night apply. I'll look it up for next time I need to access underneath.
It's a key, it fits in a keyway.
Keyway ??? It is correctly called a "Woodruff key"
Hi Mike I know that. I try to use the terminology most people use when they message me asking for help. Thanks for watching.
@@MowerMan I'd have been very surprised if you didn't know. Good to watch. My mountfield SP530 blade boss sheared & broke today,
which is what caused me to search. A new boss has what looks like slightly off square locator pins, whereas holes in the blade are round ? Stay safe.
Not know