OutdoorKing Repair Forum Forums General Discussion Forum Power Equipment...Mishaps and Funny Stuff Close call today

Got this morning from a garage sale a almost new 06 manufactured victa hawk mower for $20, nothing was wrong with it apart from the old owners had kinked the throttle cable and forced the lever to move causing the lever to move but not move the cable.

Anyhow got it running sweet, and mowed my back yard with it, I had just moved some stuff down the side of the yard and went to attack this tall grass with it when there was a loud clunk and the blade plate came out chasing me with a great deal of speed.

So after looking at thwe broken bolt and everythign else (this mower is so new the original blades are still like new) the bolt looks like it has been stretched like a peice of blu tack possibly from overtightenening in the factory or maybe a manufacturing fault with the bolt.

thankfully the disc only just missed my foot and stopped safely off to the side of the mower. Now just to get the other half of the bolt back out of the crank

Sounds like it's time to give some thought to wearing safety boots (steel toecap) when you mow, Joe. I always do.

Good advice grumpy, I do as well, and as you know I use a cylinder mower, however my edger has a rotating blade and its always good to be safe, not sorry!
Glad to see that your OK, Joe.

I have always worn boots after a few years ago when I ran over a glass ashtray and embedded glass into my foot. attached is photos of the bolt and the mower...

As you said, Joe, that bolt has necked down - it is not a brittle failure, and it was tensile rather than bending. At a guess, it was either way too tight, or it had missed the heat treatment process and was a soft bolt instead of a high tensile one. It would be possible to find out which, by doing a hardness test on the bolt, but I think the latter is more likely from the look of it. Soft bolts neck down more than high tensile bolts, before failing in tension. Most likely the bolt was soft and was already necked down after being torqued up to the level that would have suited a high tensile bolt.

Another triumph for Chinese quality control? However, it is more than 4 years old - hopefully things have improved a lot since it was made.

5 years old, only got it since i could feel the rotating assembly is perfect and the oil is crystal clear.

just have to get the rest of the bolt out now, have never had any luck with easyouts, only ever broken them leaing tool grade hardened steel to drill though after they snap.

Joe, ezyouts are not the answer to all prayers, but they can be useful when the bolt was not tight to begin with. In this case, it looks as if the bolt stretched and broke due to pressure under the head, so the stump of it should not be tight in the crankshaft. It is different when the bolt breaks torsionally: on tightening due to bottoming in the crankshaft thread, or on loosening due to being rusted in. When that happens, there are much better stud extraction methods. The weakness of the ezyout is that it expands the threaded stump when you try to extract it, because it is conical and has a left hand thread of its own. The harder you try, the worse the result. It is important to be gentle applying the torque, and if you find it won't move, change immediately to plan B.

Incidentally when you drill the stump to install the ezyout, you'll probably find out whether the bolt was soft. Drilling a soft bolt and drilling a six-stripe bolt are very different experiences.

Just a small point, Joe. Looking at the picture of the bolt, I would suggest that the safety boots you are wearing are probably due for replacement - the toe caps appear to be worn through!

Joe,you are so lucky-once you have post your toes it is very hard to walk for life,a
good lesson for every one...ken

Bejaisus! Certainly would not wanna be looking down the barrel of a blade like that one. Lessons to be learned? All is not always what it seems, newer is not always better, and steelcapped boots are for the win! It's for this reason that I am apprehensive about using pushmowers... I know the chances of such a catastrophic failure are unlikely, especially on such a new mower... but not impossible!

Took it to my father today to get the bolt out, the boss had cracked on the crank so he pulled it off and got the rest of the bolt out fairly easily! will be refitting a new boss and bolt tomorrow

You might check that the crankshaft thread is OK before you try to assemble it Joe - that bolt had stretched way out of pitch, so the crankshaft thread might be stretched as well. Usually if the damage is minor you can just clean it up by running a tap into it.

it had stretched in the non threaded part that goes through the boss and into the blade plate, ill post a pic of the other half of the bolt that came out freely later on if I can find it.

By coming out freely it demonstrates that it broke due to tensile failure, not by bottoming or seizing in the thread. You should be able to tell rather easily with a file-test whether it was heat treated or not. Everything seems to point to it having bypassed the heat treatment process, thus causing the failure. A very small error, and at least it was an external part and thus easy to fix, but a major safety problem. I hope they are heat treating all of their blade plate retaining bolts by now. It isn't a failure mode you'd want to have happen to you more than once.

Funny story following this up, I just fitted up another blade boss, brand new bolt and washer and started it, pics are going to follow this chinese manufacturing excellence.

I think from now on even if a chinese motor seems fine to me I will just pull it apart and sell it as parts, I should still get $60 n parts off this machine but I could have got over 100 if it was running right.

So the flywheel came apart and that caused some collateral damage?

If the governor was working, it must have blown the flywheel at only 3,000 rpm, which seems just about inconceivable unless it was cracked. Also, that isn't the normal pattern of a bursting failure, it looks more like a crack propagation failure. Is there any way of knowing if there was a visible crack before you ran it?

And are you sure it is a good idea to sell parts that may turn out to be of the same quality as that bolt and flywheel? Both of those failures were capable of causing personal injury.

the carbs and magnetos are pretty good on them its the acrual mechanical parts that seem to have troubles. It was running at a little higher than idle (around say the 2500 mark) it appears there is fine cracks all over the underside of it, also the keyway seems fractionally larger than it should be. if the flywheel has been avle to vibrate a little bit over time I guess it could have split it.

All the castings are very crystalised compared to the older engines also. This frame is a candinate for a decent australian 2 stroke engine and giving it a good run before finding a new home for it.

Joe, the quality of the flywheel casting comes into question, but I think there's also a possibility the flywheel retaining nut was over-tightened and the flywheel was split at the hub before it even left the factory. The radial split just propagated when the engine was run. So, the flywheel might always have been split, and the main question is whether it split because it was overtightened, or because it was a lousy casting, or both.

Hi fellas, just another example why a lot of mower repair shops won't touch Victa products any more. Just crappy gear!!

apart from the wheels the quality of the deck seems great albeit a little thinner than the old ones, the axles also seem a little soft, I have replaced these with old fashioned ones with succsess before.

Hello, this website really good.

1 x problem from Victa (blade carrier bolt)

1 x problem from B&S (flywheel)

I tend to agree with Grumpy - that doesn't look like your typical "threw itself apart" type of result.
Just a thought (probably drawing a long bow, here) - Picture this ... mower on its' side, hefty young lad (or lass) doing up blade carrier by holding the flywheel nut. Beefy enough (but without knowledge of torque limits for certain size bolts) to stretch the carrier bolt, whilst at the same time applying enough pressure to crack the flywheel (or maybe worsen an existing weakness).
Like I said, just a thought. I have seen young people doing up motherboard screws that think they're not tight unless you hear the fibreglass board crackle under them! Lots of warranty returns there!!

Igor, I'd be critical of the Victa production engineer if he has people tightening the bladeplate retaining bolt by restraining the crankshaft by the flywheel retention nut, and not even using a torque wrench on the bladeplate end. I tighten the blade plate nut on my Victa by clamping the blade plate. It's easier than taking the top cover off and more importantly, it avoids wrecking the engine. Putting about 30 lb ft of torque through a crankshaft that only develops 4 lb ft when the engine is running? That is just irresponsible.

I agree that your explanation is possible of course, and would mean that the entire mess-up happened here in Australia at the Victa assembly plant, but I'd rather think better of Victa than that. Two serious quality control procedural errors are required for your solution to apply: using a completely unsuitable way to restrain the blade plate when fitting it, and failing to use a torque wrench for a safety-critical process where assembly torque is critical. In this case it looks as if the bolt-head was rotated at least two full turns after it came up tight, so Victa may have some problems with its training and production line supervision as well.

Having said all that Igor, I have to say your explanation is not just plausible, it's elegant as a solution to what we've seen. I still don't understand how a soft bolt was used, though.

I wasn't thinking of the plant - (one would imagine they'd have pre-set air guns, etc to do that sort of thing) - more the offspring of an owner

By the way the bolt stretched, it would nearly have to be a production fault in the bolt factory - there could even be a whole batch of them out there!

Hi Igor, now that is scary!

I saw the original owner in at work today I quizzed them about the blades adnd they informed me it has never had a blade change (I didnt meantion about the faults that have occurred) and the old owner had only used it a handfull of times.

It still sounds as if the blade plate bolt went wrong in the Victa assembly plant in Sydney (both using the wrong bolt, and stretching it to the breaking point), and if igor's explanation is correct, they did the flywheel damage as well. igor, whether they use a manual torque wrench or a power-operated one, it is easy to get the wrong outcome if it is maladjusted. How often have we all seen the guys in tyre shops screw the rattle gun torque up to maximum, and let it rattle away while it destroyed some poor customer's wheels?

Grumpy, I've seen those tyre guys snap the wheel studs clean off with a rattle gun, and also who hasn't been caught out trying to get the nuts off after a flat with pissy brace supplied with the vehicle?

Right, Darryl. Long ago I used to re-torque the wheelnuts on my wife's car after every visit to the tyre shop, so she'd be able to get them off if she had to. Then modern technology arrived and I bought her a mobile phone, so she can call the RACV if she needs a wheel changed. The new system is better.