Hello All,
I have a '99 Force 120 that I run on an 18' Bayliner Capri Cuddy. The engine has been used in fresh water most of its life and it runs flawlessly.
I have recently noticed a problem after cruising for a short time at any speed above 3000 rpm or so. If I quickly slow the boat down and put the throttle in neutral, the engine will fast idle at about 1200 rpm and make an erratic pinging or ticking sound. This will continue for about 10-15 seconds, then the motor will settle down to around 800 rpm and run normally. If I come off plane and leave the boat in gear at idle for a few seconds, I can put the throttle in neutral and the motor will not ping and will idle normally.
The only thing I have changed recently was to replace the thermostat. I used a brand new Qucksilver 130 degree stat oem replacement part. Water passages around the stat and cover are all pristine condition. I do notice that the temp of the telltale is considerably hotter than the previous stat, but not to the extent of burning your skin. The engine does not seem to be overheating (tested hot horn and works) I also use NGK BUZHW plugs, the engine runs better than with the stock Champion plugs. However I have used the NGK plugs for over a year now and never had a problem.
My plan is to first check operation of the stat and make sure it is opening at correct temp. Next I was thinking of switching back to the Champion plugs and checking the timing. Any other suggestions would be greatly appreciated.
I have a '99 Force 120 that I run on an 18' Bayliner Capri Cuddy. The engine has been used in fresh water most of its life and it runs flawlessly.
I have recently noticed a problem after cruising for a short time at any speed above 3000 rpm or so. If I quickly slow the boat down and put the throttle in neutral, the engine will fast idle at about 1200 rpm and make an erratic pinging or ticking sound. This will continue for about 10-15 seconds, then the motor will settle down to around 800 rpm and run normally. If I come off plane and leave the boat in gear at idle for a few seconds, I can put the throttle in neutral and the motor will not ping and will idle normally.
The only thing I have changed recently was to replace the thermostat. I used a brand new Qucksilver 130 degree stat oem replacement part. Water passages around the stat and cover are all pristine condition. I do notice that the temp of the telltale is considerably hotter than the previous stat, but not to the extent of burning your skin. The engine does not seem to be overheating (tested hot horn and works) I also use NGK BUZHW plugs, the engine runs better than with the stock Champion plugs. However I have used the NGK plugs for over a year now and never had a problem.
My plan is to first check operation of the stat and make sure it is opening at correct temp. Next I was thinking of switching back to the Champion plugs and checking the timing. Any other suggestions would be greatly appreciated.
