Question for anyone with a mulching push mower ?

[BillK]

Hey guys,
I need a favor if you dont mind. If you have a mulching push mower can you check and see how far the blade is above the bottom edge of the deck ? I replaced the engine on mine a year or so ago and I don't think it is mulching as good as it used to. Its really been noticable this summer because of all the rain we have been getting and how fast the grass has been growing. The only thing I can figure is the shaft on the new engine might have the blade at a different spot in the deck ? Right now mine is right at the bottom of the deck.

I know this might differ from manufacturer to manufacturer but I wouldnt mind getting an idea.

Thanks,

 

[kd3pc]

22" mower Craftsman

the bottom of my blade is about 1/4" from the bottom of the mower deck. The bottom of the blade is aligned with a rolled edge of the mower deck.

 

[p00p]

same as kd3pc, but mine "colics" the grass no matter how slow or fast I push at any set deck height.

 

[mjeff87]

Same with mine (22" Poulan), about 1/4". If your blade is at the same height as the bottom of the deck, I don't think you're getting the right amount of "vacuum" to stand the grass blades up to cut them properly as the mower blade spins.

 

[alfazer]

Honda HRX537. Main blade is about 1/4" from bottom edge of deck. It also has another blade above the main blade, both fixed to the hub, turning together.

 

[cdestuck]

If you didn’t have to adjust the wheels on your mower after installing the new engine, then the blade is approx the same height as when on the old engine.

 

[redmondjp]

I would look at installing some flat washers underneath the engine mounting points to raise the engine until the bottom edge of the blade is about 1/4" above the bottom edge of your mower deck. Mainly for safety reasons. You may or may not have to use longer engine mounting bolts.

What type of mower do you have and what type of blade is now on it? Also, how fast is the blade turning? A torus (donut) shaped deck works best for mulching.

 

[BillK]

I would look at installing some flat washers underneath the engine mounting points to raise the engine until the bottom

Doing that would affect the amount of airflow out from under the engine. Not sure if that would hurt or help the mulching. I dont feel that would be a very solid fix though. If I do anything it will be to machine some off the bottom of the crankshaft to get the blade at the correct height.

Mower is a Yard Man (MTD) with an oem MTD mulching blade.

I wont have time to look at it until the weekend but I will post any updates.

 

[BillK]

If you didn’t have to adjust the wheels on your mower after installing the new engine, then the blade is approx the same height as when on the old engine.

I cut with it as high as it will go so hard to say. I did just replace all for wheels as the old ones were pretty worn out but that made no difference as far as the mulching goes. Then again it might just be because of how crazy the grass has been growing the last few months. Normally we rarely have to cut it but maybe every two weeks during July and August but this year it has really needed it every week at minimum.

 

[p00p]

If blade turn speed is too low, it will not chomp right.

 

[Negen]

My lawn mower is a self propelled walk behind/push mower craftsman something or other I did put a Oregon gator blade on it g5 I believe it's a 196cc Honda clone motor with the standard mtd blade adaptor. The Scott's branded ariens walk behind self propelled mower I keep at my rental property had the original motor piston blow out the side of the motor so I replaced it with a harbor freight motor the 99 or 199$ Honda clones and had to go through about three adaptors before I found one that was proper height for the pulley system but also used the thicker heavier weight Oregon gator blade. Both about a rough 1/4" from bottom of deck.

Sent from my ONEPLUS A6013 using The Garage Journal mobile app

 

[redmondjp]

Doing that would affect the amount of airflow out from under the engine. Not sure if that would hurt or help the mulching. I dont feel that would be a very solid fix though. If I do anything it will be to machine some off the bottom of the crankshaft to get the blade at the correct height.

Mower is a Yard Man (MTD) with an oem MTD mulching blade.

I wont have time to look at it until the weekend but I will post any updates.

I've been doing it for years (adding spacers between engine and deck) - it is plenty solid! - OEMs have done it by simply casting the lip in the deck higher. No problems. Air coming in is fine, lots of decks even have air openings in the middle (esp. on riding mower decks).

Been working on lawn mowers since 1975 - just picked up a 198? Toro Model 20684 tonight with a Suzuki 2-cycle engine and a BBC. Have a Toro with the 4-cycle Suzuki on it and have always wanted to try the 2-cycle out as it was also used on their Proline commercial models for years.

 

[spunger1]

This is a stupid one to check but have you cleaned the bag and blown out all the dirt and dust? I have a probably 20 year old craftsman mulching mower and had a similar problem. I replaced the blades and did everything I thought of and when I really cleaned the bag it worked like a champ. I guess like anything the blade spins creating vacuum but if the bag is caked with dust and dirt it kills the vacuum.

 

[BillK]

This is a stupid one to check but have you cleaned the bag and blown out all the dirt and dust?

No bag, strictly mulching.

 

[Randy_che]

Are you positive the blade is not on upside down?

 

[BillK]

Hey guys,

I got home in time to cut the grass this evening. My blade is actually about 1/4" above the bottom of the deck so thats about the same as the rest of you.

Randy, yes the blade is on correctly I dont think it would even cut the other way.

I think that it must be because the grass is just so darn thick and it has been growing a couple of inches easy every week. I cut it last Friday and I bet it was up over 2 inches taller tonight. I also have Zoysia on a lot of my lot and it is thick anyway.

Thanks for the measurements ! At least I know that part isn't an issue. I am going to order a new blade tomorrow too. The one that is on it is a couple of years old and has been sharpened quite a few times so its ready for a replacement anyway.