Yes. And if you actually identify WHICH GT5000, I'll provide some. What's the Sears 917.xxxxxx number or engine Brand, Model & Type/Spec?

***"I doubt a "defective air filter" is the cause of a wasted cam lobe on your machine. #2) I doubt the air filter has caused *only one* of your cylinders to give up the ghost either."*** I agree with that. When the air filtration is not keeping dust and grit out of the engine, the first components to suffer are the intake valves and piston & rings/cylinder walls. Secondary components to fail would be camshaft lobes, crankshaft rod journals and piston wrist pins. If you don't "see" any visible signs of filter leakage (obvious "dust tracks" or "dust streaks" showing in the areas "past the filter", dirt in the carb throat and intake manifold (some traces of "carbon black" in the intake is OK. Dirt, grit or "sludge" is not OK), about the only way to confirm the presence of inadequate filtration, is by doing "autopsy" to the disassembled engine and components. In an "autopsy", all engine components are measured with precision instruments (micrometers, dial indicators, "plastigage" to name some)and compared to the OEM specifications and/or wear limits. The two "most telling" things to measure when you suspect that air filtration has been "compromised" or "corrupted", are the diameter of the piston "skirt", and the diameter and taper of the cylinder walls. In measuring a piston, you DO NOT measure diameter anywhere in the piston ring area. The measurements are taken across the "skirt". The "skirt" of the piston is the "long, round surface of the piston sides". The skirt is the portion of a piston that actually "supports", or "carries" the side loading of the piston that occurs when the rod journals of the crankshaft are "half way between TDC & BDC" of piston travel. For this reason, the cylinder walls will wear where the skirt "rides" more than other areas. In most engines, you will be able to actually see the "track" where the piston skirt "touches" the cylinder walls. This track is where you want to measure the cylinder to determine how much it has worn. Measure the cylinder walls that are "perpendicular" to the skirt track AT THE BOTTOM OF THE CYLINDER. This point of the cylinder will give the original diameter of the cylinder when the piston was "put into service". Knowing the "new" measurement allows you to subtract that value from the measurement taken in the skirt track of the cylinder. The "remainder" from that computaion represents the amount of wear that has occurred to the cylinder. In measuring a piston, you take the diameter spec for a new piston and subtract the measurement from the worn piston. The remainder from that computation represents the amount of wear that has occurred to the piston. You can then compare all your measurement results to see if the engine would require "over boring" the cylinder to the next appropriate "oversize" of piston. Over boring a cylinder requires an oversize piston. And, you can't use an oversize piston unless you also over bore the cylinder (they only go as a "pair") If the engine features "cast iron" liners, and dirt and grit are getting into the engine, the wear to the cylinder walls will be worse than the wear to the piston. This is because the "softer" aluminum of the piston allows some of the grit to "embed" in it. The embedded grit acts like "emery" and will cut into the cast iron while the piston itself gets "less wear". Aluminum cylinders & pistons will wear about equally. Anyhow, if the cylinder walls and piston skirt exhibit "excessive wear", the wear is most likely due to bad air filtration. So, if you think you might want to "save" this engine by replacing the camshaft (which is obviously worn), you need to perform (or have it done by a "machine shop") an autopsy to determine if the engine is a candidate in the first place, and if unfiltered air was the cause. With today's costs of machine shop operations plus the high relative costs of individual replacement parts, you have to decide whether to save that engine, or replace the engine. If all other parts measure within acceptable specs, a replacement camshaft kit is likely a good way to go (even better if you can DIY). If the pistons and cylinders (even one piston and cylinder) are worn beyond the service limits, a complete new engine makes more sense. BTW, the 120 PSI versus 135 PSI on the "good" cylinder probably reflects the worn cam lobe more than the leaking head gasket.

I have the same one and it has the same problem. I pulled the plugs and seen if one of the pistons pushes in if it does you have a broken connecting rod. When mine did it it caused alot more problems I could not fix it. If you have any other questions please email me I know alot about lawnmower engine

I can offer some comments on the battery. 1) Small tractor batteries have the same dimensions, but are available in 4 power levels: (ratings are approximate) 180 cold cranking amps 230 cold cranking amps 295 cold cranking amps 340 cold cranking amps My opinion is the two lower cranking amp batteries are intended for the single cylinder engines. The large twin cylinder engines may need the more powerful batteries. 2) The same cold cranking amp battery is usually available with the positive terminal on the left or the right side. Examine the battery compartment and the location of the battery cables to determine which battery your tractor requires. 3) Some tractor batteries are sealed while others are not. The sealed batteries have the same power as the vented batteries, but the vented batteries are more likely to have corrosion problems on the cables and battery box. Vented batteries usually have the removable battery caps so that you can add watter. Seal batteries are - sealed - with out removal caps. Usually, the sealed batteries are about $5.00 more than the vented batteries. Most of the batteries delivered with new tractors are the sealed type. Places like Auto Zone, Checker, NAPA and most of the department stores sell the vented batteries - probably because they are cheaper to buy from the manufacturers. Die Hard batteries on new tractors are usually sealed. The Die Hard batteries in the Sears stores are usually the vented style. DieHard is a sticker that is placed on batteries purchased from the different battery manufacturers. 4) A Battery maintainer is an excellent tool that maintains the battery at a peak state of charge. You can leave a battery maintainer connected to a battery for the entire off season without harming a battery. The battery maintainer must be turned on all the time. A battery charger - even a trickle charger - should only be used to boost a battery - perhaps monthly - for a few hours at a time. A battery charger will cook a battery if it is left on all the time. 5) The battery electric shops usually carry a full assortment of batteries, cables, and all the charging equipment. The selection available in the department stores is usually limited. Sorry, I don't have a recommendation for a particular brand of battery. I like sealed batteries as they are less likely to develop corrosion problems.