Recently bought a used Honda Harmony 1011 SA (gear, not hydrostatic). I almost immediately began having problems with the blade belt. It would engage only on the lowest blade height settings. Eventually, it rolled off the tensioner pulley, at which time I replaced it with a Honda belt.

I then leveled the deck (right to left and front to back), made sure the blade was 2 inches per the manual at height level 2, and I lined the tensioner arm up with the markings on the deck -- all per the manual.

I head out to mow, and all goes well for about 30 minutes. Then, the belt again comes off the tensioner pulley, and loops around the wrong side of it (outside).

The tensioner pulley looks higher than the idler pulley when engaged. I do not know if this is the problem or not. I have not changed any bearings, which could be my problem, but the pulleys seemed to move OK when I turned them with the mower deck removed. Thanks for any advice.

Hi,
I would say you have diagnosed the visible sign of the problem. Check hardware that the pulley attach to. Honda is not known for its good breakdowns, but here is a link to one(Note: Check PTO Clutch and Tensioner Arm.):
All Years H1011R SA RIDING MOWER, USA Honda Riding Mower Parts (http://www.boats.net/parts/search/Honda/Riding%20Mower/0/H1011R%20SA%20RIDING%20MOWER%2C%20USA/parts.html)
Peace,
Clarke

Hi,
I would say you have diagnosed the visible sign of the problem. Check hardware that the pulley attach to. Honda is not known for its good breakdowns, but here is a link to one(Note: Check PTO Clutch and Tensioner Arm.):
All Years H1011R SA RIDING MOWER, USA Honda Riding Mower Parts (http://www.boats.net/parts/search/Honda/Riding%20Mower/0/H1011R%20SA%20RIDING%20MOWER%2C%20USA/parts.html)
Peace,
Clarke

When you say "not known for its good breakdowns" what do you mean exactly? When they breakdown they are expensive? Or they are hard to fix?

I am going to take the deck into a local dealer and have them look at the bearings for me.

Hi,
I solemnly say that I was not speaking of a failure when I said breakdown. I simply meant that it is not too obvious what you are looking at. MTD and others do this as well. You can have a difficult time tying the pieaces of the picture together.
Peace,
Clarke

I had the bearings checked and the parts dealer said they seemed fine to him. I ran it for about 30 minutes, and again, the blade belt broke. It was running great for that 30 minutes. The last 5 minutes or so, I did run through some high grass. I wonder if that did it? I really like this mower, so please help if you can.

Hi,
Should not do that. Check the spindle brake, it stops the spindle when the deck is disengaged. It may be dragging.
Peace,
Clarke

Good afternoon,

First, I must say that I am not a small engine mechanic, but experienced this similar problem and have found that the Collar C, TensionE (#17) wears out and causes the Collar Tension (#15) to rub a larger hole into the Arm Tensioner. This is the result in the movement from its position ("higher than the idler pulley when engaged"). To fix my problem I replaced the ARM, TENSIONER COLLAR C, TENSIONE (x2), COLLAR, TENSION, WASHER (10.3MM). The list of parts I purchased is below. I did add a new STOPPER D, BELT (#10) because the belt bent is several times until I figured out the problem. You may not need to replace this.

Second, there is good news. I fixed my mower for less then $80.00, with a new belt being fifty percent of the total cost. To repair the problem remove the BOLT, FLANGE (10X8) then the "collar tension assembly". Replace the needed parts and reattach the assembly. Remember to line the tensioner arm up with the markings on the deck.

I found the best prices and service at Boats.net. I the below hyper link will take you to the parts manual.

http://www.boats.net/parts/search/Honda/Riding%20Mower/0/H1011%20SA%20RIDING%20MOWER,%20USA,%20VIN%23%20MZA W-6000001/TENSIONER%20ARM/parts.html

11-50372-MR8-000 : COLLAR
11-76123-772-L01 : ARM, TENSIONER
11-90527-230-000 : WASHER (10.3MM)
11-91559-772-L00 : COLLAR, TENSION
11-91568-772-L01 : COLLAR C, TENSIONER
11-94103-10800 : WASHER, PLAIN (10MM)

11-76257-772-L00 : STOPPER D, BELT
11-94001-08000-0S : NUT, HEX. (8MM) IN STOCK
11-90101-750-920 : BOLT, SPECIAL (8X20)

The belt is 76181-772-L02

Hi All
My riding Harmony, not near by so can't give the model # has had the same problem of the belt coming off the tensioner and going to the back side for years. What I have done time after time is bend the tensioner arm to better track with the rest of the system, that works for a short or long time depending on how high the grass is or what sticks or rocks find their way to the blade. The arm needed to be made of a heavier material or a heat treated steel to resist the bending issue with the increased load. I also have had the fixed idler to the rear of the tensioner bend somewhat adding to belt alignment problems.
Cheers,
BP

My problem was the out of alignment pulleys it seems. I took the deck off and took it to nearest Honda place which checked the bearings out as OK. They adjusted the pulleys for me and we put belt on. Took it home, leveled the deck again and it's been cutting great ever since. Now I need to sharpen the blade!

Here is a link to the belt 76181-772-L02 on Partspak.com:

http://www.partspak.com/productcart/pc/Honda-76181-772-L02-V-BELT-BLADE-4575p366966.htm

PartsPak.com prices are usually the lowest on Honda parts. You can just enter the part number in their search bar or use their free parts diagrams. They also have pictures for most of their parts, so that you can make sure you are buying the right part the first time.

If you choose to change the blade here is the part on Yamaha Honda Mercury Boat Jet Ski ATV Motorcycle Repair Parts Johnson Evinrude Suzuki Kawasaki Polaris - PartsPak.com (http://www.PartsPak.com).

Honda H1011 SA Mower Blade (http://www.partspak.com/productcart/pc/Honda-72511-772-L00-BLADE-ROTARY-4573p364756.htm)

I find they have the cheapest prices on Honda parts.