Blade won't stay on Honda Mower

[sblg43]

http://i284.photobucket.com/albums/ll25 ... fced75.jpg

I have this MTD mower with a Honda engine. The owner said the blade came off while mowing. I take it home and notice that the blade adapter has been stripped on the inside where the adapter slips over the crankshaft. OK, says I, easy fix.

http://i284.photobucket.com/albums/ll25 ... C05796.jpg

So I put a new blade adapter on and fire it up. It sounds a bit "clunky" but eventually the sound stops and the engine sounds smooth. So I release the bar to kill the engine and suddenly the blade falls off! WHAT THE.....HUH?

http://i284.photobucket.com/albums/ll25 ... C05795.jpg

I look underneath and I find that the new blade adapter is stripped on the outside (the four pointed star part).

I did check for a bent crankshaft but it is straight as an arrow.

It's almost as if the blade can't keep up with the motor and it spins off. I must point out that at first, I did not have a lock washer on the bolt and I did use my impact wrench to attach the blade. I think that it's possible that I didn't tighten it enough (I didn't use a torque wrench to check the torque ) Before I go out and buy another $22 blade adapter, is there any other reason this would happen?

I also think the "clunking" is unusual. But I can't tell if it came from inside the engine or from under the mower deck.

[Deere2me]

The clunkin' came from the blade not being tight! When ya put yer impact on it, you prolly lost the registration 'tween the pegs and the holes in the blade. I always hold everything in alignment with one hand , and impact with the other. Is the blade on upside-down? BTW, that adapter is costin' way too much.

[bgsengine]

http://i284.photobucket.com/albums/ll25/sblg43/Small%20Engines/3f9a8fe5-c5ff-4680-92d6-d7aab5fced75.jpg

I have this MTD mower with a Honda engine. The owner said the blade came off while mowing. I take it home and notice that the blade adapter has been stripped on the inside where the adapter slips over the crankshaft. OK, says I, easy fix.

http://i284.photobucket.com/albums/ll25 ... C05796.jpg

So I put a new blade adapter on and fire it up. It sounds a bit "clunky" but eventually the sound stops and the engine sounds smooth. So I release the bar to kill the engine and suddenly the blade falls off! WHAT THE.....HUH?

http://i284.photobucket.com/albums/ll25 ... C05795.jpg

I look underneath and I find that the new blade adapter is stripped on the outside (the four pointed star part).

I did check for a bent crankshaft but it is straight as an arrow.

It's almost as if the blade can't keep up with the motor and it spins off. I must point out that at first, I did not have a lock washer on the bolt and I did use my impact wrench to attach the blade. I think that it's possible that I didn't tighten it enough (I didn't use a torque wrench to check the torque ) Before I go out and buy another $22 blade adapter, is there any other reason this would happen?

I also think the "clunking" is unusual. But I can't tell if it came from inside the engine or from under the mower deck.

Are you sure you got the right adapter? there's a huge difference between a 7/8" and a 25mm - look up the correct part number for the mower, make sure the mower has the original engine, and then make sure the adapter you order is O.E.M. There are some aftermarket cross references that are way wrong.

Second, make sure you replace that spring washer (the diamond shaped washer between your bolt and the blade) as it should be cupped , and it looks like it has lost its spring tension (as if someone heated it with a torch) and finally, make sure your blade is the correct part number (There are some aftermarket "will fit" blades that are "close", but they do not fit the adapter correctly... we only use OEM blades on those applications - and most of the popular MTD blades are under the "edge" program, so are supposed to be priced very competitively with aftermarket blades.. )

As was mentioned, your "clunk" is because the blade was not seated correctly to the adapter. - meaning the blade was loose, when you let go the MZR bail, blade kept going after the crank stopped... causing your shearing problem.

Make sure the adapter seats *FULLY* all the way on the crank , make sure the keyway is correct and not bogged out or damaged (adapter should be a snug slip fit - use emery cloth to clean off the rust, and a dab of anti seize compound when sliding it on the shaft) then manually assemble things until blade is SNUG to the adapter with bolt finger-tight , and then, only then torque the blade bolt.

[Mek-a-nik]

I've put a couple adapters on because of "clunking" (on start up). They would still clunk, but not as bad with the new adapter. I temporarily put paper in the keyway of the adapter, it gets quieter, but not good. I'm thinking that a loose blade hammers the keyway in the adapter and the crank, leaving the key fitting loose. I would think a new crank, inaddition to the new adapter, is the only total fix, not practical at all.
Paper shim is not a long term fix, obviously. I want to try shimming with some feeler stock that I have. I don't think even the .0025" stuff will fit over the key.

[sblg43]

Thanks all for the responses. The blade adapter was OEM from MTD and at the same time, I replaced the "bell blade support" (the diamond shaped part). As far as the price of the adapter goes, $20-$25 seems consistent with internet pricing (shipping included). So it looks like I will try again with another OEM adapter. I will find an OEM blade as well, and I will pay special attention to the installation. I just hate telling the customer that he has to wait a little longer while the grass is growing... that's life.

[Deere2me]

Thanks all for the responses. The blade adapter was OEM from MTD and at the same time, I replaced the "bell blade support" (the diamond shaped part). As far as the price of the adapter goes, $20-$25 seems consistent with internet pricing (shipping included). So it looks like I will try again with another OEM adapter. I will find an OEM blade as well, and I will pay special attention to the installation. I just hate telling the customer that he has to wait a little longer while the grass is growing... that's life.

Ya might wanna check Fleabay, last one I bought was like $8.50 with free shipping.

[bgsengine]

Thanks all for the responses. The blade adapter was OEM from MTD and at the same time, I replaced the "bell blade support" (the diamond shaped part). As far as the price of the adapter goes, $20-$25 seems consistent with internet pricing (shipping included). So it looks like I will try again with another OEM adapter. I will find an OEM blade as well, and I will pay special attention to the installation. I just hate telling the customer that he has to wait a little longer while the grass is growing... that's life.

Ya might wanna check Fleabay, last one I bought was like $8.50 with free shipping.

It won't be O.E.M. That's below dealer cost... for just about any of them.

[Deere2me]

Thanks all for the responses. The blade adapter was OEM from MTD and at the same time, I replaced the "bell blade support" (the diamond shaped part). As far as the price of the adapter goes, $20-$25 seems consistent with internet pricing (shipping included). So it looks like I will try again with another OEM adapter. I will find an OEM blade as well, and I will pay special attention to the installation. I just hate telling the customer that he has to wait a little longer while the grass is growing... that's life.

Ya might wanna check Fleabay, last one I bought was like $8.50 with free shipping.

It won't be O.E.M. That's below dealer cost... for just about any of them.

Does it need to be?? Why pay an arm and a leg for a green plastic bag? If properly installed, an aftermarket one should work perfectly.

I would bet money that you have installed many non-oem parts ,no??

[KE4AVB]

Thanks all for the responses. The blade adapter was OEM from MTD and at the same time, I replaced the "bell blade support" (the diamond shaped part). As far as the price of the adapter goes, $20-$25 seems consistent with internet pricing (shipping included). So it looks like I will try again with another OEM adapter. I will find an OEM blade as well, and I will pay special attention to the installation. I just hate telling the customer that he has to wait a little longer while the grass is growing... that's life.

Before ordering another adapter I would check that crankshaft key way for damage. Also check and make sure the current blade isn't hitting the inside of the deck walls.

[bgsengine]

Does it need to be??

No, but the O.P. is specifying OEM parts, and my comment is to point out for the benefit of anyone else reading this thread that the OEM part may be pricier, but the part you price quoted is *not* an OEM part.

Why pay an arm and a leg for a green plastic bag? If properly installed, an aftermarket one should work perfectly.

*IF* properly installed, so will an OEM part. - with Aftermarket, there are a lot more "IF"'s involved - *IF* you get one that meets the quality standards it should.. *IF* it wasn't a poorly made one in a chinese factory on sub-standard machining equipment.. *IF* it is not one of those (relatively common) ones that slip through quality control checks (just throw em all in a box as they come off assembly line, no inspections for quality.) *IF* the dimensions are correct - on some machines, "Close enough" just ain't.

I would bet money that you have installed many non-oem parts ,no??

Oh sure, we often do - most often where we don't have a readily available source for OEM parts, or where we are not concerned with quality - In the same way you *claim* nothing leaves your shop without a 1-pull start (I have my doubts, there's some stuff that just *doesnt* have a 1-pull start, period.) - it is all about quality - and the warranty behind it. if we use OEM parts from our OEM supplier, we are backed by parts and labor warranty if the part fails... if we use aftermarket, and something goes wrong, *WE* have to eat the parts and labor... So, yes we will install aftermarket, but only where we absolutely have to.