MTD GOLD LAWN TRACTOR WHEN ENGAGE PTO AND LOWER DECK . SLOWS DOWN TURNING BELT SLIPING

ed, be sure there is nothing wrapped around the blades. lower the deck and be sure the belt is around all of the pullys. If the belt comes off one of the pulleys or the pulley on the engine it may feel normal but it wont engage the blades.

On that type PTO engagement there is slack in the belt that disengages the deck, in some case there is a arm with a idler pulley that swings against the belt to tighten it and engages the deck , in other cases like older MTD:s the deck swung backwards as it was let down and tightened the belt and was lifted to turn it off. Most of the decks had a brake of some kind on the deck pulleys to stop freewheeling of the blades when disengaged .

Only seen one or two H decks here.
if it is this cable

then it connects to the RH brake assembly and the PTO engagement plate. There is also a spring that connects at the same point on the engagement plate to the right hand frame.

There are 2 springs involved with PTO and deck belt system. They both connect to bolts standoffs. I linking you the parts diagram at Partstree where you can look at the parts layout. Hope this helps.

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MTD uses several different configurations. Electric PTO's are tensioned all the time by an idler pulley on a spring loaded bracket. Manual PTO's with an engagement lever have a movable bracket attached to the lever via a cable that will tension the belt when the lever is engaged. Another configuration is the deck engages when the deck is lowered with the deck height lever and disengaged when the deck is raised. In this case the belt is tensioned by a large spring from the rear deck support bracket to a mount on the transaxle and tension is released by a rod that pull the deck forward when it is raised.

it will be near the rear of all the pulleys probably just above top of pulleys look for a simple hole where it hooks usually a 1 inch piece of stock

You have a short somewhere . A cut or stripped wire that , at the time of lowering your deck, touches the body. It's like turning off your key. Look around under your deck and you will find what I'm talking about. Fix wire and tie up to prevent future problems. GOOD LUCK.

One or more of your drive belts is in need of adjustment or replacement, maybe. Possibly, your electric (or manual) PTO clutch could also be adjusted. You do have the spring tensioner on the deck engaged, right? You say the engine doesn't bog when this happens so I am inclined to think "clutch" and/or "PTO belt" to the deck and/or the "deck tensioner" are the things to check.

The tensioner will be the easiest, it is a handle on the left side ON the deck. Has a BIG spring on it. Make sure it is engaged.

Is yours a Troy Bilt manufactured in Troy New York or is it another manufacturer (MTD?). Troy Bilt is actually out of business, having sold the Troy name to a variety of makers depending on the model line. I don't have the run down on who makes what any more (tillers, chippers, mowers, blowers, trimmers, etc.), but Troy Bilt of Troy, NY is no more. :-(

I have a 16 HP Troy with 42 inch deck driven through a electric clutch. I also have a "grass pump" on my deck. Important maintenance tips: Keep the bearings greased, keep the deck clean underneath. The belt on the deck should have the tensioner released when you are NOT mowing. Keep the blades sharp and in good repair. Mow with engine at full speed. When you get to areas of heavy growth, slow the tractor down (hydro drive) or reduce to a lower gear (gear drive). NEVER adjust speed using the "clutch" (hydro drive or gear drive). When you engage the blades (electric or manual) always have the engine just above idle, bring the engine speed up slowly to preserve the belts and reduce stress on all components.

I am sure this is the fix for your trouble. If there is anything else or if I missed the ball, please let me know and we will go further.

Thanks for your question @ FixYa.com

It sounds like your blades may be restricted when you lower them. A possible solution for this problem would be to remove the mower deck and clean out all the dead grass buildup inside the housing.

Be sure the belt is the correct size and is routed correctly.

If you are not sure, you can download a manual here:
http://manuals.mtdproducts.com/mtd/public/list.jsp

You will need the model & serial numbers.