Hey all, I've got a 1993 DT25C. I've got the factory service manual coming as a christmas present, but I'm hoping y'all can give me some help before that arrives as it is duck season here in Arkansas.
I bought the outboard used. Fresh full rebuild. New rings, pistons, bearings, full machine work, etc. It has maybe 15 hours on it.
I'm having an issue with the idle. For these Mikuni carbs, when you screw out the idle mixture screw, does it lean out the mixture? I synced up the linkages so all three throttle plates are sitting closed together. They were slightly off and I thought that might be my issue. No change. My mixture screws are 4 turns out which seems a bit much to me, from what i've read online. It should be closer to 1.5-2 if what i'm reading is correct. If I screw them in, it starts to sneeze and cough. It idles smoothly around 850rpms in gear with them set at 4 turns. All of this was set with the motor warmed up in the water on the boat off the trailer.
Also, should the throttle plates be completely closed at idle? As in no gap at all? As of right now, they are opened slightly per adjusting with the idle speed screw on the middle carb.
She runs like a race horse. No lag or stumble. Gets up and goes. Plugs looked fine. Nice and brown. Piston color looks good too from what I can see through the spark plug hole in the head. She isnt leaking oil out the prop to suggest running overly rich after idling for awhile like my old johnson would.
It's worth mentioning the motor has some "work" done. Bored pistons. Shaved head. 30 carbs and linkage. Cut tuner. Drilled exhaust. I have a set of Boyesen reeds waiting to go in when I have time as well.
Any suggestions or insight?
I bought the outboard used. Fresh full rebuild. New rings, pistons, bearings, full machine work, etc. It has maybe 15 hours on it.
I'm having an issue with the idle. For these Mikuni carbs, when you screw out the idle mixture screw, does it lean out the mixture? I synced up the linkages so all three throttle plates are sitting closed together. They were slightly off and I thought that might be my issue. No change. My mixture screws are 4 turns out which seems a bit much to me, from what i've read online. It should be closer to 1.5-2 if what i'm reading is correct. If I screw them in, it starts to sneeze and cough. It idles smoothly around 850rpms in gear with them set at 4 turns. All of this was set with the motor warmed up in the water on the boat off the trailer.
Also, should the throttle plates be completely closed at idle? As in no gap at all? As of right now, they are opened slightly per adjusting with the idle speed screw on the middle carb.
She runs like a race horse. No lag or stumble. Gets up and goes. Plugs looked fine. Nice and brown. Piston color looks good too from what I can see through the spark plug hole in the head. She isnt leaking oil out the prop to suggest running overly rich after idling for awhile like my old johnson would.
It's worth mentioning the motor has some "work" done. Bored pistons. Shaved head. 30 carbs and linkage. Cut tuner. Drilled exhaust. I have a set of Boyesen reeds waiting to go in when I have time as well.
Any suggestions or insight?