Yard Man Collects a LOT of Grass Around the Motor

[l008com]

So I used this machine for the first time yesterday and it has some weird grass behavior. All that grass around the motor, it does that very quickly. With the rear flap closed, as shown, most of the grass shoots out the bottom of the flap, but some of it shoots out the top, right under the hinge. Not a ton, but apparently not a ton is still enough to fill that thing up with grass very quickly. I kept cleaning it out as I went but it kept filling right back up.

So you'd think something must be bent, like the housing is bent down or the flap is bent up, making a gap up there. But everything looks straight and correct. This is an old mower (27 years) so maybe they just didn't have mulching nailed down back then? Although based on where the grass shoots out, i would expect it to have the same problem even with a bag installed. (though I don't have one so i can't test).

Anyway, all this just to ask, has anyone see this odd problem before, and if so what's the fix? It looks like a simple strip of adhesive foam might do the trick, although I'm not sure how well that would stay in place. Looking at all I can find for a parts diagram, there doesn't seem to be any kind of missing filler piece or anything. Hrmmmm.

 

[ILENGINE]

Some of those mowers used to come with a mulch plug that inserted into the hole under the flap when not bagging.

 

[l008com]

Some of those mowers used to come with a mulch plug that inserted into the hole under the flap when not bagging.

Ahhh I think that might be it! And at $50 each, guess who's NOT buying one! lol

 

[Auto Doc's]

When the clippings build up, they have to go somewhere. These are designed as a dedicated bagger unit.

 

[ILENGINE]

Bagger/mulcher actually with the required mulching plug.

 

[sgkent]

what others wrote. All the mulching mowers I ever owned needed a mulching plug. Unfortunately they seem to bring a small fortune even used on ebay. Sometimes Amazon has the right one. Without the model and serial number for your mower, it is unlikely anyone here can help you look for one.

 

[l008com]

This is actually the FIRST mulching mower I've ever owned that needed a plug. They are crazy expensive. Thats too bad, I could probably build one out of scrap wood and prime and paint it. But all things considered, I think my best bet is to just use some kind of adhesive foam to make a little wall on the top of the flap hinge so the grass can't shoot up there, and just falls back down instead.

As far as the model number, @ILENGINE determined it to be this in an older thread:
1999 or 2000 12A-559K401 or 12A-559K402

$60 for the plug is what I saw online. Not worth it.
As far as I can tell the part number is MTD 7825007C

Looking at more pictures online, I am confident that I could make a pretty good mockup out of wood. But I'm definitely not doing that either.

 

[l008com]

I didn't like the adhesive strip options at the hardware store, but its a very thin gap so a layer or two of gorilla tape should fix this problem and not even be noticeable.