G
Greg Reichert
Guest
"I started a thread last Octob
"I started a thread last October that I'm hopefully in the process of bringing to a close now. The link is here http://www.marineengine.com/discus/messages/12488/114866.shtml
My engine is an '85 OMC 3.0 liter. The basis of the problem was an inability to reach proper W.O.T. Bob recommended a full tune-up at the time, and after another season of sub-par boating at between 3600-4100 peak RPM, I finally did the entire tune-up today (new points, condenser, plugs, rotor, both fuel filters, and timing check.)
The plugs had little black spots on the electrodes when I took them out; my Clymer manual hinted this might be from overheating or improper timing. When I checked timing it was Way Off. The timing mark was well forward of the timing check plate. If I had to guess, it was somewhere in the mid to high 20 degrees BTDC at an idle. I adjusted it down to the manual-recommended 4 degrees BTDC, and this drastically slowed the idle and caused a faint ticking noise in the carburetor. I called a mechanic that I trust and he told me that I should set it at about 8 BTDC. This increased the idle RPM a bit; it runs more smoothly, but the ticking noise from the carb seems to still be there most of the time. It wasn't there when the timing was set at its previous location, but of course it now runs much better. Back on the lake, I was back in the 4200-4600 RPM range with higher speeds. Idle seems lower than it had been - possibly not a bad thing- but I don't know if I should worry about the ticking noise.
Any help would be greatly appreciated. Thanks in advance."
"I started a thread last October that I'm hopefully in the process of bringing to a close now. The link is here http://www.marineengine.com/discus/messages/12488/114866.shtml
My engine is an '85 OMC 3.0 liter. The basis of the problem was an inability to reach proper W.O.T. Bob recommended a full tune-up at the time, and after another season of sub-par boating at between 3600-4100 peak RPM, I finally did the entire tune-up today (new points, condenser, plugs, rotor, both fuel filters, and timing check.)
The plugs had little black spots on the electrodes when I took them out; my Clymer manual hinted this might be from overheating or improper timing. When I checked timing it was Way Off. The timing mark was well forward of the timing check plate. If I had to guess, it was somewhere in the mid to high 20 degrees BTDC at an idle. I adjusted it down to the manual-recommended 4 degrees BTDC, and this drastically slowed the idle and caused a faint ticking noise in the carburetor. I called a mechanic that I trust and he told me that I should set it at about 8 BTDC. This increased the idle RPM a bit; it runs more smoothly, but the ticking noise from the carb seems to still be there most of the time. It wasn't there when the timing was set at its previous location, but of course it now runs much better. Back on the lake, I was back in the 4200-4600 RPM range with higher speeds. Idle seems lower than it had been - possibly not a bad thing- but I don't know if I should worry about the ticking noise.
Any help would be greatly appreciated. Thanks in advance."