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You know the things , those lumps of cast iron, rubber mounted under the car, to gearbox mounts etc, you'd think car would go better if you removed the coupla kilos ..... I am looking for the smallest ones youve seen, if they exist. Like to try and dampen vibration in my lawn mower to stop it coming up the handle. Already a four stroke so less vibes, have tried bradflex pipe insulation but it wears out, and got Youngstown anti vibe gloves. Wondering if I can apply some smarter thinking.

Only FROG would know the tchnical or part name for these things ...???

Can you take the whole blade base assembly off, take it to a wheel and tyre place and get them to balance it like they would a wheel? I imagine a fair chunk of the vibration comes from that being not perfectly balanced?

purp wrote:Can you take the whole blade base assembly off, take it to a wheel and tyre place and get them to balance it like they would a wheel? I imagine a fair chunk of the vibration comes from that being not perfectly balanced?

Too complicated just to make your lawn mower better. If you can take the blade assembly off and it has a round hole through the middle you can balance it yourself; put it on a suitable sized rod and hold it up or put it on some V blocks. If one point constantly drops to bottom it's heavy, add/remove weight or move things around until it doesn't roll around of its own accord.

Back to your cast iron vibration-eaters Jonno; I have no idea what you're talking about, sorry

Wheel balancer won't do...maybe a blade change will help. Not suspected in the plate, just typical engine vibration. Think you can shake a 4 stroke to bits on solid mount, eventually.

Sam, all over the place under cars in last ten years at least, look like dags hanging off th back of or below things like gearbox cross members etc - all for NVH reduction. Under bonnet, hanging off all kinds of driveline componets


LATE NEWS BREAK:

Dynamic dampners is what the parts interpreters call these doo dads, well , ebay here we come, some little ones please

Jonno,

I have a little old Victa Utility with a 3hp 4-stroke Briggs & Stratton motor with exactly the same problem. I've even had the blades replaced a couple of weeks ago trying to reduce the vibration. Mine also has a flywheel, I'm not sure but most Utilities may have come with a 2-stroke Victa engine and perhaps a blade bar (not sure) although I would've thought the 2-strokes would need the flywheel more.

Having said that, I think there's a lot of mechanical-type noise when my earmuffs are off and the serial number code says it's a 1980 B&S, so maybe it's just an end-of-life issue :-/ ! It runs quite well otherwise.

I was thinking of vibration absorbing material for the handle, e.g. bike handlebar or raquet handle tape, or perhaps rubber washers or some thin hard closed-cell foam in the folding handle join.

Let me know if you find a solution!

Patrick.

Jonno,
Gonna check this out on my mower- possible damage to the flywheel key. It's near the top so easy to inspect. Damage caused by hitting rocks/logs/etc, the key is designed to shear to prevent other engine damage in a big hit. Damage to / shearing of the key is a source of vibration as it binds the upper flywheel to the crankshaft.

May be of use if you have a B&S 4-stroke. See here.

Patrick.

They do have a good site, old B & S, eh? Thanks for the results. It is B & S 4/ and has hit the odd rock, gutter, effing brick, dog toys - all more than once...WTF was that ??
Gotta love 4/'s for needing to lift and tilt correct way or drown carb in sump oil and the need to drain sump to look under. Must be time for a change anyway.

Gonna also drag its spare brother out - a 550 instead of a 500 series and compare vibrations

blush, blush



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$30 for a set of four masport blades at the mower shope, or $24 at Burnings and done, the catcher will fill more efficiently, not sure what we have done to improve vibrations ..

Jonno, have you been mowing a gravel garden? Seriously, whilst your blade cutting edges are worn it seems you've lost the upturned part of all 4 blades. Not sure what's happening there.

I pulled to top cover off my mower and on the flywheel I found a broken fin and another chipped one. I think this may be contributory to my vibration issue. Think I'll have to try and source a new flywheel. See attached pic.

Mate, that mower has done everything from grass to brick and everything in between dog turds, rocks, and today , some reo mesh ingrown in the grasses picked up a corner and well - I should have replaced the broken rear brace bracket sooner. Did that this arvo, cut down the only one in stock - marked 18 for an 18" mower, to fit my 19" - yeah, go figure ?
Used my Ryobi electric pressure washer to clean under first - the cut in cut out is a joy compared to the petrol driven one.Gasless mig came to the rescue on the welding of the braces two halves I created, popped it in so no more narrowing of the rear body to mess with ma new blades