The deck is way too low. A backfire is a loud boom or bang that occurs when the engine slows rapidly. Cutting grass at #3 deck height just scalps the lawn. The deck is low enough in position 6 that I use that to mow. Loosen the hanger adjustments and then re tighten them. The mower cuts the grass too "low" even when the cutting deck level is raised to the highest level (#6). This is a Craftsman Rider made by MTD. It’s packed with 25 years experience, tips, tricks and hacks and the best part, you’ll save a packet on mower repair bills. The mower deck sits way too low. It is actually scalping the grass in places. Front tires that are too low or rear tires that are overinflated can cause the appearance of a poorly adjusted mower deck. Check the mower deck for misadjustment, slow down or raise the deck if its too low. If this doesn't work, check to see if the deck is warped, it may be twisted. It is designed to occur with very little effort on your part. Scalping is when the mower deck comes close to or hits the ground. Nothing happens to further lower the deck in position 4, 3, 2, or 1. Position 5 is too low. Model 247-203700. Most all mower decks have an adjustment. Test your riding mower after you have made the adjustments to make sure it it cutting well and that it is cutting the grass level. Now, ... My Craftsman riding mower, 42" double blade with 18hp engine is not cutting even it is cutting high on the right side. It appears to be a rebranded Troybilt Pony / Model 700. I adjusted the front to raise it however stll too low. Hopefully the numbers match and the problems isn’t due to a bent arm or other part. MOWER DECK REMOVAL & INSTALLATION NOTE: Perform mower removal and installation on a hard, level surface such as a concrete floor. WARNING After lowering the mower cutting height, engage parking brake, turn off the mower blades, turn the ignition switch to STOP, and remove key before attempting to install or remove the mower. This video shows how to adjust and level the deck height of your riding mower. My 2011 Craftsman lawn tractor (Model #917.28851) has a 6 position level to raise and lower the mowing deck, 1 being lowest, and 6 highest. I have tried to adjust the blades and the deck without much luck. Step 2 – Raise Mower Deck Cutting Height. Scalping can be caused by the mower deck misadjustment, unevenness in the lawn, or by the mower deck bouncing because the ground speed is too fast. Park on a level spot and lower the deck all the way down as low as it will go. I have been using a Toro mulcher for years and use the "D" and "E" settings to mow my yard. If you need video help, check out my mower repair video library, it walks you through a ton of common mower maintenance and repair jobs like blade sharpening, pull cord repair, no start trouble-shooting, carburetor cleaning, self drive faults, etc. I have a lot of scalpng at the six setting onslightly uneven terraine and the sun raises cane with the health of the grass. If you remove the pin from the bracket on the frame of your lawnmower, this will allow you to move the deck up or down. . My Riding Mower Backfires & Has a Loss of Power. In addition, find the riding mower parts you need to fix your mower. Adjusting an uneven deck is the same process but you will need to adjust one side of the deck to make it even with the other side. I moved the deck attachment to higher holes on the attachment brackets. The problem I am having is the highest position of the deck cuts the grass way to low. When setting the cutting height on six the actual height of the cut is only about 2 1/2 inches. Your mower deck might be set too low if it is scalping the lawn. Conclusion: Now I am wondering if I have made a huge mistake by buying a riding mower. For additional repair help, including common symptoms and troubleshooting tips, step-by-step riding lawn mower and tractor repair guides, and articles, check out our repair help section.