They are designed to shear if you hit a rock or tree stump etc to prevent you from damaging the crankshaft and then needing a new engine. I have quite a few engines with bent cranks due to this. When you start getting shake vibrations you'll then know you've Damaged the Crankshaft. All these home made videos keep my business turning along nicely. Honda's are a favourite for damaging the Crankshaft. Good luck everyone.
I think you have to put a little bit of metal on the shaft called a woodruff key or moon key , if you miss this out I think it breaks the adapter easily 😀👍🇫🇷
I TOOK PLASTIC GUARD OFF JUST 2 T20 SCREWS TO GAIN ACCESS, BELT HAS TO BE TO SLIPPED OVER TOP PULLEY. HOME MADE PULLERS DONE THE OLD PART REMOVAL, LINE UP KEY WAY WITH NEW PULLEY AND TAP ON FIRMLY WITH PIECE OF WOOD. REFIT PLASTIC COVER MAKING SURE IT FITS OVER WATER PIPE, PLACE BLADE IN SITU AND FIT HOMEMADE DEVICE I USED 3MM PLATE .
I haveing the same problem mate two times I've had to get one so did what u did drill it and put 🔩 on it but still shear off but will try this way as becoming a joke now half way through a garden
very interesting. I am trying to replace my blade boss after the pins sheared on my mountfield, How did you get the piece off the drive shaft, may I ask?? regards
I have the same mower .... Its broken also ... Is the £20 part easy to fit as the belt obviously needs to come off and how do you get it off the drive shaft?
To replace the blade boss you need to pull it off from with a bearing puller as it's a tapered shaft, they are quite cheap £5 or less the belt does not need to be removed at all in fact nothing does appart from the blade.
@@grant605gb Many thanks for getting back to me .. I've had the plastic bottom cover off and yes the whole build of the mower is crappy ... I will buy a cheap axle puller tomorrow ... Get the part and give it a go. Looks like it might be a regular job! :-( Thanks again fella!
@@grant605gb I only ask because there are two sizes of blade boss crank. You show the one fitted for a honda engine. Im not familiar with the mountfield engine. I was sent out a honda size one and put it on a briggs. The result was it shattered after one use. Didnt do any damage to the crank luckily. They are exactly the same apart from the hole fitting.
No there is no extra vibration at all, all older style mowers and most commercial/farm machinery use this type of attachment to prevent this exact issue. This is only ever a cost saving design from the makers cheap, fast, poorly made, poorly designed
Hi - same problem here - I have shelled out for FIVE of these useless blade bosses and they shear even under minimual stress. Question: with your solution is the OEM bolt which holds the blade on still long enough?
MarkN it is long enough yes, it only adds 6-7 mm depth , had my new modification on now for months on a blade boss with ripped out lugs and mower is going 4-5 hours a day and no probs at all
