Today we will be looking closely at some valvetrain noise in the rear cylinder, identifying the source, the cause and quite possibly a fault in the lifter setup. Since this has effected the bike over the rebuild the lifters or the adjustment procedure could be suspect.
allsun Ultrasonic Air Leak Detector Automotive Listening Device Stethoscope
amzn.to/3LuBVQn
The bike is prepared for lifter removal, and well be braking out my measuring tool that I suspect is the culprit, it at least one of them. Starting with the rear exhaust lifter its removed and cleaned and inspected. Then placed back in, followed by the intake. Starting with the intake the pushrod is reinserted just until there is no deflection it is expanded one flat at a time.
Turning in 4 turns in in an older method and checking with the measuring tool we see the tool is calibrated to 4 turn from the top. Now I continue to turn in to full seat to see how many turns there are in total. It bottomed out at 8 turns. If documentation in the book is correct I should be 1.5 from the bottom which would be 6.5 turns from the top, not 4.
So all setup will be from the bottom, 1.5 turns up. The Exhaust will be done in the same manner. Followed by the front ones. Ill point out that these push rods are old and worn and I plan to replace them. With the bike buttoned up, a slow turn of the engine checks clearance and we run it and listen.
No noise was observed when it was cold so we go for a ride. But as it warms up we hear the noise from the rear. Determining its a lifter making noise and a good idea it was the exhaust, I purchased a new one from S&S and swapped it out.
The Noise was gone at full temperature after that but with the digital scope I can see a hint on the other lifter so i decided to swap that one as well. For a fully quiet drivetrain.
#shovelhead #lowrider #motorcyclerepair