I think something is awry if you had a failure in such a short time. If the blades were loose enough to strike - off goes your timing right there. The tensioning part really isn't difficult in itself. After I set tension, I roll the spindles around a few times and loosen the tensioner pulley a turn and make sure the tension is correct - then resecure the nut. The barrel like guide should be in place and facing the correct way. If you watch the rotation of the deck- are the blades on the proper sides? Is there reason to suspect wear on the slide area or the cone? It sounds like you are saying that someone else did the work prior. Loosen the idler as far as you have to to roll a spindle inside the belt to get it back in time and then follow your bulletin and all should be fine if the rest looks as it should. Use the JD parts look up as a guide.

Are you talking about the primary deck belt or the traction belt? The traction belt is a couple hours plus of fun if you haven't done one. So much so you'll want to replace the plastic idlers so you don't have to do it again if they are originals. When you pick up belts, have them print you off the diagram and ask on the timing tension adjustment. The manual would be better. Just be sure to have the complete model/ serial off the tag as there are 2 versions of the beast. You maybe able to get the owners manual online at deere.com Here is a link that might be useful: Deere parts

This looks like something in development. Maybe someone is trying to replace the conventional timing chain with a belt, but this doesn't make sense to me. Possibly, the thinking is a cost reduction. Physically, its merely a matter of changing the sprockets on the cam shaft and crankshaft to one designed for toothed belts, but from a mechanical designer's view, this makes no sense. Possibly, a belt would be quieter. However, a chain drive can approach 98% efficiency and a belt can not. Ultimately, a belt will need replaceing at the expense of removing a gasketed belt cover and all the labor required to get to it. An enclosed belt can not be inspected unless a port hole is provided. It does eliminate the seal on the camshaft extension. I would think that a belt tensioner is required, the same as for a dry belt. Maybe this application is for a motorcycle engine. Look at the evolution of engine development in Japan and it seems they use motorcycle engines for their test beds. Several developments appear on motorcycle engines a few years before these are found in automotive engines (from Japan). To name a couple I know of: 4 to 5 valves per cylinder; Counter balance shafts.

The only information that I've got is for the 1992, 2.3 L engine in the Ford Topaz. (It's probably the same basic layout as for the pickup truck.) So, with this warning, here's the information for the car engine. There should be two timing marks: one on the crank grear and one on the cam gear. These are punch or drill point marks. Both gears are keyed to their shafts. There is an inside and outside face for the gears. The timing marks face to the outside. The chain will have to be placed on the gears before sliding the gears onto the shafts. This may not be easy since one or both of these gears may be press fits. If you encounter a press fit, just take it easy and press each part a little at time while keeping the chain aligned. The object is to avoid damage to the chain. The keyway on the cam shaft points toward the crank. The key on the crank points straight up (and not toward the cam shaft). After the chain and sprockets are in place, the timing marks (on the sprockets) should point toward each other and be in-line with the center-line of the cam shaft and crank. (The crank key will not be on this line.) Slowly rotate the engine by hand to check for interference with a valve. If all seems ok, then check the rotor position in the distributor. It should be ok since it was not removed, but here's the check anyway. With piston no.1 at top-dead-center (TDC) and on the compression stroke (both intake and exahust valves closed), the rotor in the distriburor should point toward the electrode (in the cap) for No. 1 sparkplug. Hopefully, none of the pistons hit a valve when the chain broke. While the timing chain cover is off, it might be a good idea to flush out the oil pan to remove any debris therein, like broken chain parts. Tiny pieces probably won't cause a problem so long as these are too large to pass by the oil pump intake screen. However, larger pieces may get bounced about and caught between close passing moving parts. You can use used engine oil as a flush fluid, or a mild cleaner such as kerosene.