The 4th Horseman
New Member
Hi everybody,
I've encountered an issue recently that I've been trying to figure out for a while and I'm running out of ideas.
I completed my first service on my 2018 RC390 about a week or so ago. Measured the valve clearances (3 out of spec: both intake, one exhaust), shimmed em to spec, swapped the oil out for Motul 300V, adjusted the chain tension, etc.. I should mention (in case it matters) this took a while, since I found the tool that KTM provides for hand cranking the engine was incorrectly sized, and had to order a 14mm Allen wrench. All in all, the full service was dragged out over a couple weeks and the bike had been sitting a couple weeks before that. Got everything thrown back together, and even waxed it so it can look good the first time it hits 10k rpm. Piece of cake. No real issues encountered, except for the typical pains of working in tight spaces and fighting with some of the more difficult connectors and such.
Go to fire it up for the first time: I can hear the fuel pump priming, good. Hit the starter, and it churns and churns but the engine won't turn over. Try it a few more times with no luck. No flashing warning light or error codes shown either.
I immediately figure it's the spark plug. I heard the fuel pump prime, and obviously didn't touch that at all, so as long as it's making noise, I know I didn't break the connector during fuel tank removal, so it should be fine at 620 miles. I did however have to disconnect the spark plug connector and remembered being concerned about not having a good way of verifying it was fully seated, way down in that deep well. Seemed like a good starting point. I did check all the fuses first, and they all checked out.
I stripped everything off again, and resistance tested the spark plug connector/ignition coil, just to be thorough. All seemed good. Pulled out the spark plug, cleaned off some carbon deposits, and resistance tested that. Again, seems good. Connected it to the connector, just to see how it seats and to get a feel for what a good seat felt like for my second assembly attempt. While I was at it, I did a resistance check from ignition coil to the plug electrode. Everything checked out. I even measured a resistance back to the battery lead. I had no idea what that should be, but it came out on the order of a Mega-ohm. It was really a half-assed continuity check, which passed.
So I reinstalled the plug and connector, got all the necessities back on, turned the key, heard the fuel pump prime, hit the ignition, and same deal: starter churned and churned but no engine start.
I'm at a loss here. None of the 4 essentials for starting (fuel, air, compression, spark) should have been affected at all during this work, with the exception of the connector de-mating and re-mating, which is tough to screw up. Does anyone have any ideas? What could I have possibly done? Any help would be much appreciated.
I've encountered an issue recently that I've been trying to figure out for a while and I'm running out of ideas.
I completed my first service on my 2018 RC390 about a week or so ago. Measured the valve clearances (3 out of spec: both intake, one exhaust), shimmed em to spec, swapped the oil out for Motul 300V, adjusted the chain tension, etc.. I should mention (in case it matters) this took a while, since I found the tool that KTM provides for hand cranking the engine was incorrectly sized, and had to order a 14mm Allen wrench. All in all, the full service was dragged out over a couple weeks and the bike had been sitting a couple weeks before that. Got everything thrown back together, and even waxed it so it can look good the first time it hits 10k rpm. Piece of cake. No real issues encountered, except for the typical pains of working in tight spaces and fighting with some of the more difficult connectors and such.
Go to fire it up for the first time: I can hear the fuel pump priming, good. Hit the starter, and it churns and churns but the engine won't turn over. Try it a few more times with no luck. No flashing warning light or error codes shown either.
I immediately figure it's the spark plug. I heard the fuel pump prime, and obviously didn't touch that at all, so as long as it's making noise, I know I didn't break the connector during fuel tank removal, so it should be fine at 620 miles. I did however have to disconnect the spark plug connector and remembered being concerned about not having a good way of verifying it was fully seated, way down in that deep well. Seemed like a good starting point. I did check all the fuses first, and they all checked out.
I stripped everything off again, and resistance tested the spark plug connector/ignition coil, just to be thorough. All seemed good. Pulled out the spark plug, cleaned off some carbon deposits, and resistance tested that. Again, seems good. Connected it to the connector, just to see how it seats and to get a feel for what a good seat felt like for my second assembly attempt. While I was at it, I did a resistance check from ignition coil to the plug electrode. Everything checked out. I even measured a resistance back to the battery lead. I had no idea what that should be, but it came out on the order of a Mega-ohm. It was really a half-assed continuity check, which passed.
So I reinstalled the plug and connector, got all the necessities back on, turned the key, heard the fuel pump prime, hit the ignition, and same deal: starter churned and churned but no engine start.
I'm at a loss here. None of the 4 essentials for starting (fuel, air, compression, spark) should have been affected at all during this work, with the exception of the connector de-mating and re-mating, which is tough to screw up. Does anyone have any ideas? What could I have possibly done? Any help would be much appreciated.
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