Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

Sears riding mower not discharging grass properly


2muchgrass's Avatar
Member

Join Date: Jul 2009
Posts: 209
MD

08-24-09, 11:43 AM   #1  
Sears riding mower not discharging grass properly

I've never encountered this one before. I repowered a Sears mower with an 18HP vangaurd Twin. It did have a single 18hp.
Everything was fine until lately I noticed that it wasn't discharging as well as it should. I changed the blades, cleaned the deck thoroughly and put the deck back on. Grass will start to collect at the rear part of the discharge chute and then just clog up totally. I stop, shake the deck to dislodge the clog and continue to cut for a few minutes and it starts to build up again. I run it at full speed but I'm thinking that because it is a twin instead of a single, it doesn't run at the same speed as the single did. Is this possible? Can I adjust that?

 
Sponsored Links
31YTech's Avatar
Member

Join Date: Feb 2008
Posts: 1,263
FL

08-24-09, 02:24 PM   #2  
Soon as I read the thread title RPM's came to mind, You actually need a Tachometer to properly set high speed RPM's, This particular one counts hours as well so you can keep track of maintenance. Adjust as below;






Good Luck

 
2muchgrass's Avatar
Member

Join Date: Jul 2009
Posts: 209
MD

08-26-09, 07:59 AM   #3  
Yes, after I posted I went back down and studied a bit more on it. I saw that tang and wondered what would happen if I bent it forward a bit. So I did. It helped but did not completely eliminate the problem. I wasn't sure if it was the correct thing to do until I came back up and read your reply. What are the RPMs supposed to top out at?
You know what I think? When I replaced the belt, the only one I could find was 1 inch longer than the original. There is no tension adjustment that I can see, I think the belt is slipping a bit when it gets into heavier stuff. I need to go get a new belt, I think. That is unless someone can tell me how to put more tension on the belt.

 
31YTech's Avatar
Member

Join Date: Feb 2008
Posts: 1,263
FL

08-26-09, 09:24 AM   #4  
The high speed RPM's should be in the 3600 range, And always install the proper length belt to ensure proper operation.....

 
2muchgrass's Avatar
Member

Join Date: Jul 2009
Posts: 209
MD

05-16-10, 04:09 PM   #5  
I pulled that thing out the other day because my main tractor ran out of gas and I was too lazy to go out and get some. I forgot all about the discharge problem.
It occurred to me that last year I replaced the mulching blades with discharge blades. If the mower was a mulching mower (eg mulching deck?), is swapping out the blades a bad thing to do?
Someone mentioned to me that it might be a deck designed for mulching. I've never heard tell of such a thing.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,573
GA

05-16-10, 10:32 PM   #6  
Mulching blades are not made to discharge clippings. They are made to be used with a cover that blocks the discharge chute and keeps the clippings under the deck to "mulch" them. Without the cover, and with thick and/or wet enough grass, it will clog like you mentioned with mulch blades installed.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
2muchgrass's Avatar
Member

Join Date: Jul 2009
Posts: 209
MD

05-17-10, 12:15 PM   #7  
What I meant to say was, the machine came with mulching blades but I took them off and put discharge blades on. It just deosn't discharge properly and someone said it was because it was a mulching deck (even though it does have a discharge) and it won't ever discharge correctly. Like I said, I've never heard of such a thing.

 
indypower1's Avatar
Member

Join Date: May 2009
Posts: 634
NH

05-17-10, 01:41 PM   #8  
can you post the model number of the mower?

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,573
GA

05-18-10, 12:03 AM   #9  
I must have mis-read, I see that now. Is the deck bent anywhere? Has the baffle across the front underside been removed?


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
2muchgrass's Avatar
Member

Join Date: Jul 2009
Posts: 209
MD

05-18-10, 08:49 AM   #10  
917.273640 It's the weirdest thing. It is probably something stupid I'm overlooking. It starts with just a tiny clump of grass in the aft top or bottom corner of the discharge chute then no grass at all is coming out and I have to stop, back up and shake a huge clump loose. It doesn't seem to matter much if the grass is wet or dry. When the grass is dry I can go a bit longer before it happens.

 
mickblock's Avatar
Member

Join Date: Feb 2009
Posts: 616
IN

05-18-10, 10:47 AM   #11  
You never mentioned the belt again? You had said that you thought it was to big.
When you put the new engine in did you use the original drive pulley or the one that came with the engine? 'Cause if they are different sizes then you may be looking at having to divine the correct belt size without using the model no.

The tension on the belt is supplied by a sliding plate with a spring attached to it. the spring is what pulls on the plate which pulls the tension around the blade pulleys, but if the plate is sticky the tension won't come on fully. It's part of the manual engagement
So if you think this might be sticking a bit then you can take off the deck (Weee!!) and remove and light sand between the two mating surfaces as well.

And you're right about it possibly being something stOOpid! Could be a piece of kite string wedged up inside one of the blade mandrels! (?)

 
jl66redcpe's Avatar
Member

Join Date: Nov 2006
Posts: 369
NJ

05-19-10, 04:28 AM   #12  
Is it possible that you installed the blades upside down ?

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,573
GA

05-19-10, 10:43 PM   #13  
Good question. I see a lot of mowers with the blades on upside down for some reason.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
mickblock's Avatar
Member

Join Date: Feb 2009
Posts: 616
IN

05-20-10, 03:20 PM   #14  
Posted By: jl66redcpe Is it possible that you installed the blades upside down ?
You would tell us if that turned out to be the solution wouldn't you?

how about - if you don't post back and tell us - just know - we're all assuming that.

 
2muchgrass's Avatar
Member

Join Date: Jul 2009
Posts: 209
MD

06-03-10, 09:41 AM   #15  
Sorry about the delay. The place was sold and the new owners have kept me pretty busy. I kind of put that mower on the back shelf for a bit but the other day I needed it so I started going over all the ideas y'all mentioned. The tension plate seemed ok but I cleaned it up anyway just to make sure. The pulleys on the two motors were identical. I did replace the belt and it is tighter so I guess the other one was getting a bit worn out. But FIRST, I checked the blades. They are indeed installed correctly. It would be the kind of dumb mistake I would make. The blade says "This side Down" so that's what I would do forgetting the deck was upside down.
No improvement. If the grass is real dry and not very tall, it will go a long time before clogging up. I have relegated the machine to doing areas I won't take my trusty 15 year old machine into.
One thought, though. The old 18 horse was a single cylinder. The new one is a two cylinder and consequently does not run as fast as the single cylinder. I guess that's because it doesn't have to? Maybe a smaller pulley on the crank? Is that feasible?

 
Search this Thread