Hey guys, this response may be a little late, BUT I have a craftsman 917.275810 with a 31P777-0296-E1 motor in it. First let me say this is a 2006 mower, i have only ever changed the belts, battery, air & oil & oil filters and recently the stator and couple of deck pulleys and levers. My engine would either barely get past the compression stroke OR not get past the compression stroke at all, I thought it was because of that 'compression release on the camshaft' wasn't working or worn out. So here is the order of tests I did:
1. I tested the Volts from the battery to the starter. Was a good 12+ volts.. So I know the solenoid and battery was good.
2. Adjusted the Valves to specs
3. While spark plug was out, i tested the starter to ensure it turned over engine with easy - It did
4. Put back spark plug re-tested the start, it still had a bit of a hard time with the compression still so I know something still wasn't right..
NOW, here is was my thought process. Should I
1. Remove the engine from chassis & tear apart the engine and pull the cam (which all this is very time consuming and dirty, let alone the belt pulley is a pain to remove if you don't have the right tools to work with). Don't forget, you'll have the drain ALL the oil out or you'll have a mess to contend with..
OR should I
2. Look for another possible cheaper, simpler solution first.
My motto is KISS (Keep It Simple Stupid). Ok so what would be a simple thing to replace from battery to engine start? Oh, the Starter (cause I already checked the battery, solenoid right to the starter), ok so I bought a 30'ish dollar starter.. Guess what, the new starter cranks right past the compression stroke with no issues. The original OEM starter was just wore down after 12 years. My mower is garage kept, but your mower is left outside in the elements, the start may wear down that much faster, within a few years instead of 12 years like mine. Moisture, heat and cold will take a toll on parts. I really hope this helps others cause it will save you a ton of headache time from ripping the engine apart to change a cam that possibly doesn't even need that. I have not read anywhere in all my searching where anyone suggest to replace the starter. Please do yourself a favor. IF you run into an engine not getting past the compression or having a hard time going past the compression stroke, consider a starter replacement. This may not work for everyone but is a cheap easy first try as fixing the compression stroke issue. Yes, you need to set the valves, YES you need to check your battery, YES you need to ensure the motor turns over easy with start while spark plug is out. If you have the OEM starter that has been on there for a while, this might be a cause/solution for you as well. Even if the start doesn't fix it, check into the return policy before you buy, you may be able to return if that is not the issue. At that point you can start thinking about tearing the engine apart for a cam replacement and maybe even leave the new starter on as you KNOW this is new now. In my case, it was the starter that was the issue. It just got weak over the years. My mower cranks up and doesn't even flinch on the compression stroke now. So I only spent 30 bucks for starter that actually fixed it in my case vs. 70+ bucks for a new cam (plus all the headaches to pull engine to get to cam shaft replaced).
I seriously hope this helps out others in the same situation I was in. As always, do your research as much as possible before you just up and buy parts.
