Idler Extension Spring Location... arggh

[mceee]

Hi guys,

MTD 13AI617H118 (2002) 46" 21hp

The other day while I was mowing, the double engine pulley actually sheered in two. Yes, the lower pulley (pto) broke away from the upper pulley (drive). Fortunately nothing else appeared to be damaged, and although the blades stopped immediately, I was actually able to drive the mower to my driveway and look at what had happened. This established that the drive system was operational as normal. I ordered the double engine pulley... it came in... and I prepared to replace.
Of course before dropping the old pulley in order to replace it, I had to relieve the tension on the drive belt, which I did according to the manual instructions. I should have taken a pic of where the Idler Extension Spring (732-0429A) connected... arrggghh. I know it connects to the furthest outer hole on the Double-Idler Bracket (683-0251), but then to what? The diagram shows it connecting to a Hex Cap Screw (710-0344), but when I connect it to that I it doesn't create enough tension for the belt to engage (i.e. the mower goes nowhere)! I've confirmed the belt routing, etc. and do not know what to do.

Please help.
Thx,
Mitchell

 

[mechanic mark]

http://service.mtdproducts.com/Training_Education/769_06667_700_series_riders.pdf Start at page 53 and scroll down.

http://www.mtdparts.com/equipment/mtdparts/partfinder#Error click anyway

 

[mceee]

Thanks so much for information... I looked at it, and mine is actually a 600 series mower.
Nevertheless I figured out the problem. The double engine pulley, which my manual says is part #756-0982b, has a smaller diameter where the drive belt seats than the original (it took me forever to see this!). Therefore the place where I remembered hooking the spring was correct. Its just that, with the smaller seating area of the new pulley, the drive belt had too much slack. Even when I used a shorter screw and got the mower moving, it goes WAY TOO SLOW. This of course is because the seat area of the drive pulley is smaller (same engine speed as before, more rpms on the smaller pulley = slower speed. It is not going to work.

So I have ordered another double engine pulley #756-0983b. From the specs, it looks like the correct pulley. We'll see. If it turns out to be correct, then the manual was a misprint (or the part actually simply changed)

Nightmare... I just need to gut my grass. Or soon bail the hay.

 

[upnorth]

there's a bracket under the pulley with one hole in it. one end of the spring goes here, the other end goes in the lower hole on the angled bracket on the opposite chassis. it is easier to install the spring if the belt is taken off the idler, then use a flat pry bar to pull/push the belt over the idler.