asignabove
Cadet
- Joined
- Feb 25, 2004
- Messages
- 20
I have had a problem with the motor knocking on de-cell for a while now. A little history. Motor: 2001 115hp Johnson Ocean Pro(bought used)- The original powerhead burned a hole in #1 piston, replaced powerhead and determined the cause to be timing advanced 10 degrees fast(at least that is what the mechanic advised). When new powerhead was installed and after about 2 hours of break-in it developed a very prominent knock on de-cell. I was advised by the manufacturer that the knock was normal on 60 degree rebuilt powerheads. Well either by faulty machine work or something else after 15 hours the #1 piston blew the rings and the powerhead was replaced again. Now even with the new powerhead I still have the very prominent knock.<br /> The other day I was running the motor in the driveway and was using the throttle on the motor to increase the RPMs and noticed that when I increased the throttle and let go I did not hear any knock at all. I then got in the boat and used the throttle quadrant and noticed that when I used the throttle quadrant, a lever on top of the motor near the timing set would move along with the throttle I was using to manually increase RPMs and when I decelerated the knock was there. I then moved the 2 levers on the motor manually and there that knock was. I then just moved the throttle by itself and low and behold no knock.<br /> I now think that there has to be something wrong in the ignition timing ???? but not sure. Everybody I talked before I figured out that it doesnt knock when I use the throttle on the motor said that the knock was normal and to just de-cell slowly, but the sound is very loud and prominent and I have never heard a motor knock this loud. Any ideas on what may be going on would be appreciated.