Engine noise
Club Member
Joined: Feb 2007
Posts: 2,404
Likes: 12
From: Haymarket, VA
I doubt the noise is piston slap. I have pulled TC engnes down with 25k and more miles and the hone marks look new and the coating on the thrust faces of the pistons has not a mark. The piistons in these engines are cast and setup at very tight toleraances; like .0006"-.0015". If the pistons were forged and set up at loower tolerancs, I might by piston slap if the noise was audible on start up but went away when the engine warmed up.
That kind of noise is difficult to run down. Noises don't migrate; if you are sure the noise is coming from a different location; it's a different noise. There are several possibilities and you just have to start running them down, checking the easy ones first.
Start with a general but close inspection of the bike; look for loose fasteners and worn accessories that might be moving and coming in contact with something else. Check the heat shield clamps. primary and check the compensator/engine sprocket. Could be loose, springs could be loose and letting it rattle. Check the primary chain adjustment to see if it is adjusted per spec.
Next is the valve train; are the valves ajusted properly; are the pushrods rubbing the tube at the top; were the rocker boxes aligned when installed; with 49K miles, you could have enough wear in the rocker shafts and shaft end play to generate noise;. Thats a counter balanced engine and you could have something going wrong wih the couter balances.
So many sources of noise on a Harley, some just get ear plugs and ride until something falls of or breaks.
That kind of noise is difficult to run down. Noises don't migrate; if you are sure the noise is coming from a different location; it's a different noise. There are several possibilities and you just have to start running them down, checking the easy ones first.
Start with a general but close inspection of the bike; look for loose fasteners and worn accessories that might be moving and coming in contact with something else. Check the heat shield clamps. primary and check the compensator/engine sprocket. Could be loose, springs could be loose and letting it rattle. Check the primary chain adjustment to see if it is adjusted per spec.
Next is the valve train; are the valves ajusted properly; are the pushrods rubbing the tube at the top; were the rocker boxes aligned when installed; with 49K miles, you could have enough wear in the rocker shafts and shaft end play to generate noise;. Thats a counter balanced engine and you could have something going wrong wih the couter balances.
So many sources of noise on a Harley, some just get ear plugs and ride until something falls of or breaks.
Advanced
Joined: Nov 2009
Posts: 69
Likes: 1
From: MS GULF COAST
Engine noise
My bike did the same thing. First the noise started on the right front side. I started with the lifters and nothing then I pulled the cylinders and found the pistons scared and the cylinders. So I thought the carb leaned out and scared the cylinders. I boared the cylinders .010 over and installed new pistons and rings. I also installed a stage 1 carb kit from cv performance thinking this would solve the problem. When I started it up the noise was still there. The next thing to do was go into the bottom end. So I shut her off and started over. I removed the motor and started to disassemble the entire engine. When I split the case on the bottom end there was the problem. The rod bearing of the middle rod journel was damaged and damaged the crank pin. So I ordered a new rod assembly with a 3 hole crank pin for better oiling. The stock crank pin only has 1 hole for 3 rod bearings. I then assembled the engine and fired her up. This bike never ran so smooth and sounded so quiet as now. So being your noise sounds the same as mine thats what I would suspect your noise is also. Cut your oil filter open and inspect it for metal inside the filter, if it has metal don't run it another minute. The rotation of the rod assembly throws the metal in the lower part of the cylinders and causes more damage to your pistons and cylinders. A friendly word of advice be careful don't run it till you find out if the filter has metal in it and good luck. If you have any questions feel free to pm me. Oh yes I almost forgot my engine only had 37,000 miles on it and I don't run my bike hard at all.
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,225
Likes: 6,292
From: Honah Lee
Fatbagga did you have to replace the crank assembly? I have never had to split the case. Was the rollers still turning in the bearing? It appeared my crank in my 04 does not break down like the older ones and what your are describing with the 3 oil hole crank pin
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