Knocking/ tapping/ rattling overnight?
2000 ultra classic 80k on the bike, 15k on the 103 kit
I just rode my bike 600 miles to the beach for vacation. I let it sit overnight and went to start it this morning to go grab some food and it immediately started clattering and died. It sounded like a rod turned loose in the tone of it. I thought my starter Jack leg got hung or something so I tried again. Same thing. Did it again and it finally started and the clattering stopped, but its only running on one cylinder and backfiring pretty bad. Oil pressure is right on the money, no more noise, spark plugs are fairly new. I swapped the plug wires to see if it would make a difference, and it made it not run at all. Pulled the plug wires and the oil cap to see if air from the cylinder was going through the case, it wasnt. Im going to run a compression check and electrical diagnosis if the compression is there. But Im shocked. It ran perfectly fine all the way down here, was shut off several times along the way and started right back up just fine. No hiccups, spitting, sputtering, etc. never had an issue with this bike. Any ideas? Bad coil? Bent valves? Bad crank sensor?
I was able to start it the following day after I posted, and it ran like it was firing both cylinders at the same time or something and wont idle without cracking the throttle a little. I went out and got a few things to do tests at the condo and the compression was 125psi in the front and 90psi in the rear. That threw me way off. Added oil to the rear cylinder, no change in psi. Did a leak down test on both, 4 hours each. Neither one dropped a single psi. Im back home now, I had to trailer it 600+ miles home. I tore into the bike today, rockers, pushrods, lifters, etc look good. I havent pulled the heads (last resort). Primary cover was pulled, all looks well no snapped/worn tensioner, compensator was tight. Drained the oil, no metal shavings in it or on the plug, pulled the crank sensor, no metal shavings stuck to it. Im pulling my hair out. At this point, Im leaning towards overheated cylinder(s). The noise is constant, idling, accelerating, decelerating (although it sounds a bit louder of a tapping when letting off the throttle), etc. its not progressed worse, but its definitely not better. I dont think its a bent valve due to the leak down tests. But this was a solid 13 hour straight ride, half or more of that time was in the 105 degree Georgia and Florida heat. Any suggestions??? I do have a video of it running on hand and you can clearly hear the noise. Any help is appreciated. Thank you!
2000 ultra classic 80k on the bike, 15k on the 103 kit
I just rode my bike 600 miles to the beach for vacation. I let it sit overnight and went to start it this morning to go grab some food and it immediately started clattering and died. It sounded like a rod turned loose in the tone of it. I thought my starter Jack leg got hung or something so I tried again. Same thing. Did it again and it finally started and the clattering stopped, but it’s only running on one cylinder and backfiring pretty bad. Oil pressure is right on the money, no more noise, spark plugs are fairly new. I swapped the plug wires to see if it would make a difference, and it made it not run at all. Pulled the plug wires and the oil cap to see if air from the cylinder was going through the case, it wasnt. I’m going to run a compression check and electrical diagnosis if the compression is there. But I’m shocked. It ran perfectly fine all the way down here, was shut off several times along the way and started right back up just fine. No hiccups, spitting, sputtering, etc. never had an issue with this bike. Any ideas? Bad coil? Bent valves? Bad crank sensor?
I was able to start it the following day after I posted, and it ran like it was firing both cylinders at the same time or something and won’t idle without cracking the throttle a little. I went out and got a few things to do tests at the condo and the compression was 125psi in the front and 90psi in the rear. That threw me way off. Added oil to the rear cylinder, no change in psi. Did a leak down test on both, 4 hours each. Neither one dropped a single psi. I’m back home now, I had to trailer it 600+ miles home. I tore into the bike today, rockers, pushrods, lifters, etc look good. I haven’t pulled the heads (last resort). Primary cover was pulled, all looks well no snapped/worn tensioner, compensator was tight. Drained the oil, no metal shavings in it or on the plug, pulled the crank sensor, no metal shavings stuck to it. I’m pulling my hair out. At this point, I’m leaning towards overheated cylinder(s). The noise is constant, idling, accelerating, decelerating (although it sounds a bit louder of a tapping when letting off the throttle), etc. it’s not progressed worse, but it’s definitely not better. I don’t think it’s a bent valve due to the leak down tests. But this was a solid 13 hour straight ride, half or more of that time was in the 105 degree Georgia and Florida heat. Any suggestions??? I do have a video of it running on hand and you can clearly hear the noise. Any help is appreciated. Thank you!
Sorry about your issues...
I was going to guess maybe a collapsed lifter or an adjustable pushrod (if you uesd them with the 103 kit) got loose... but you checked those...
I read your post 3 times, sorry if I misunderstood or missed this info.... but I have a few questions:
You posted the results of the compression test, 125 front/90 rear.... The rear cylinder is way out of spec and should be within 10% of the front.... What were the results of the leak down test....?? Did they both hold at that psi, or are you losing air from the intake, exhaust, or breathers?
You mentioned the "rockers, pushrods, lifters, etc look good". What are the etc? Did you open the cam chest? Are the spring cam tensioners both OK? Are the inner cam bearings, or cam plate bearings for that matter, all good too....?? Did you update the cam plate/inner cam bearings when you went to the 103...?
Last edited by hattitude; Jul 26, 2021 at 09:04 PM.
I was going to guess maybe a collapsed lifter or an adjustable pushrod (if you uesd them with the 103 kit) got loose... but you checked those...
I read your post 3 times, sorry if I misunderstood or missed this info.... but I have a few questions:
You posted the results of the compression test, 125 front/90 rear.... The rear cylinder is way out of spec and should be within 10% of the front.... What were the results of the leak down test....?? Did they both hold at that psi, or are you losing air from the intake, exhaust, or breathers?
You mentioned the "rockers, pushrods, lifters, etc look good". What are the etc? Did you open the cam chest? Are the spring cam tensioners both OK? Are the inner cam bearings, or cam plate bearings for that matter, all good too....?? Did you update the cam plate/inner cam bearings when you went to the 103...?
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