Sears LT1000 Ride on won't start with new carb...

Joebklyn · Jun 24, 2018

(SOLVED) Hi, I have an old Sears 917-272082/ kohler Pro CV490/27505 ride on mower. I replaced the carb at the end of last summer with a cheapo $35 carb. Now it's mowing season again and it was working fine for 2 weeks or so. It began to stumble/stutter would recover and work fine for a bit. I barely got it into my garage by working the choke lever before it died. I ordered and receieved a new OEM Kohler carb thinking that's the problem. I put all new fuel lines/fuel shut off valve/filter on. I installed the new carb and nada. Engine cranks but won't start. Attached spark plug tester. Plug is getting spark. Tried starting it with a shot of starting fluid, nothing, it did not run at all on a decent shot of ether. Oil is good at proper level. I'm out of ideas. Grass is getting taller, wife is getting...well 'ya know. Does anybody have a direction I can go in? Thanks for reading this. (It has new coil too.) SOLVED: It was the flywheel key. Although I hit nothing to break it, it was indeed broken. There was just enough 'bite' on it to allow the flywheel to spin. It looked smeared to me. However, this threw off the timing so the spark tester was showing a spark but not at the right time. Spent $120 on a new carb I probably did not need now I have a spare. Cost of the key: Kohler X-42-15-S $1.95

Maxify55 · Jun 24, 2018

The valve lash has probably opened.

Meaning that your valves aren't opening and closing at the proper intervals/

Here are some YouTube vids that can explain it, and the corrective measures, far better than I can.

valve adjustment kohler courage - YouTube

radios1 · Jun 24, 2018

look at the plug, is it wet from the unburned gas?. you could have a spun flywheel, check the key, make sure it's not damaged.. it should be flat on all sides.. with air, fuel, sufficient compression, and a spark at the right time, the engine will run..

woody · Jun 24, 2018

you checked it with a spark plug tester but did you check the spark plug?

tomplum · Jun 24, 2018

Skip the valve lash as this is Command, not a Courage. A plug is good thing to try as it is cheap and quick. A cheapo neon spark tester isn't a dependable test if that is what is being used. Grounding the plug at the block is somewhat better. Even with that, you can have a spark and the CD in coil gets buggy and won't throw the spark at the proper time. The flywheel key is a good idea, though you must pull the flywheel to inspect. It is a woodruff / half moon key rather than a square. Does the engine seem to crank over normally to where you can verify that it has compression- or does it spin easily? These can have the exhaust valve seat come loose and stick the exhaust valve open. Throw the starting fluid away and use carb spray as a better alternative.