bighermHK45
Petty Officer 3rd Class
- Joined
- Jun 17, 2012
- Messages
- 92
Motor: 1999 Merc 125
Parts replaced: Plugs, wires, CDMs, voltage regulator, fuel filter, fuel line/primer bulb from tank to motor
Maintenance completed: Sync and link, oil pump adjusted
Finally, I was able to get the boat in the water. When I went to accelerate the throttle did not engage like I am used to. When the 3 and 4 cylinders kick in at about 2000 rpm the rpm immediately surged to 3000 rpm (I about lost the wife out the back of the boat). When I throttle back slowly I can reduce rpm to 2900. Any more reduction in throttle and the rpm drops to 2000 immediately.
If I try and slowly manipulate the throttle past 2000 rpm (in essence trying to circumvent the 1000 rpm surge) the motor bogs down and sounds flooded.
So, where should I start investigating the surge issue? It should be known the motor runs great from idle to 2000 rpm. And from 3000 rpm until WOT it runs very good. But the 2+2 transition is not performing as intended. Previously, I have owned a Merc 115 2+2 and am aware on how the transition is supposed to behave.
Any practical experiences or advice is appreciated.
Parts replaced: Plugs, wires, CDMs, voltage regulator, fuel filter, fuel line/primer bulb from tank to motor
Maintenance completed: Sync and link, oil pump adjusted
Finally, I was able to get the boat in the water. When I went to accelerate the throttle did not engage like I am used to. When the 3 and 4 cylinders kick in at about 2000 rpm the rpm immediately surged to 3000 rpm (I about lost the wife out the back of the boat). When I throttle back slowly I can reduce rpm to 2900. Any more reduction in throttle and the rpm drops to 2000 immediately.
If I try and slowly manipulate the throttle past 2000 rpm (in essence trying to circumvent the 1000 rpm surge) the motor bogs down and sounds flooded.
So, where should I start investigating the surge issue? It should be known the motor runs great from idle to 2000 rpm. And from 3000 rpm until WOT it runs very good. But the 2+2 transition is not performing as intended. Previously, I have owned a Merc 115 2+2 and am aware on how the transition is supposed to behave.
Any practical experiences or advice is appreciated.