2003 DT225 will not start...runs perfect

[seaox230c]

So I started this post 2 months ago but it got erased...long background. Had this motor since new. Started within 2 -5 seconds of cranking every single time ever, even after winterizing and fogging. Early may, dropped it in the water and drove the 30-40 min across the bay to the dock...no issues what-so ever. Parked it and went home. Next day would not start. Tried every throttle position...no help. Hung a spark plug jumpered to block...no spark. Had no tach bump during cranking, per the manual... check yellow engine rotation signal out of ICU. Looking for 12v ...had 1 +. Checked the resistance of every timing coil and gear counting coil, and checked the voltage output of all 4, same as the last 15 years when I did some testing..per book, bad ICU. Replaced with supposedly good unit, no help no start..didn't help. Didn't recheck spark.. then I checked every sensor and wire on the engine...couldn't find anything. Tried anything that would kill spark...kill switch, tach, ignition switch, rotor head...all no help. In the end changed all 4 timing coils, and stator coil , ICU AGAIN, CDI, and regulator...started 4 or 5 times..went home. Next day...WOULD NOT START. Checked for spark..sparks during crank. Checked fuel pressure....36psi and did not drop after 15 min so injectors not leaking. Pushed throttle up hi, engine starts. Took for a 1 hour run. ALL PARAMETERS PERFECT. Idle hi speed fuel flow, temp smooth running. Went back to dock and turned off...WOULD NOT RESTART..waited 15 min...would not start no matter where throttle was set...im almost done with this devils plaything

[artdf175]

Yes this site has gotten real flakey.. Have sent messages to the supposedly "*****" - but multiple requests are all unanswered


I don't have the wiring schematic for a DT model
but on the DF model there are a couple of things that suppress the spark
would start with the throttle position sensor
the DF model will not start with the remote in any position but in netural. My DF model has two sensors one in the remote and the other where the shift cable terminates on the engine.
If it started at WOT, that is not good or what it is even supposed to do.

Art

[Solarman]

I might check the neutral safety switch at the motor. The TPS and the oil flow switch. The oil flow switch could need to be cleaned (old oil not flowing well?), or replaced? It can affect spark if not working properly?
I know you have checked everything multiple times, but this appears to be an intermittent electrical problem and until it is located will cause much grief.
This motor is 21 years old, but that doesn't mean it is dead. It means some contacts might be wearing thin, starting to fail?
The gear counting coil if mounted correctly (not all rusted), and the TPS (valve not sticking, sliding smoothly) and both reading good per manual? How old is ignition switch, isolation switch?

The neutral switch can easily be jumped just to test, but motor will start all positions (F-N-R), thinking it's in neutral-limiting rpms. Be careful to use neutral position only.
Might check voltages going into ICU, you have the manual, follow the wiring diagram.
It is possible for wires to look new, but may be corroded internally?

Good luck, post back on what you find out.

[seaox230c]

So starting at high throttle mystery solved....noticed the top of the motor was wet with oil, and smelled like fuel. Sprayed solvent up there with the engine running....rpm increased. Have a crankcase leak up top.. Took off the flywheel, stator and timing base to get to the upper crank seal, expecting it to be torn. Found the aft crankcase seal retainer lip snapped, allowing the seal to lift off the main bearing seat and letting air in and out of crankcase,Through the openings in the main roller bearing thus stopping normal airflow into the cylinders at idle /start. But at high throttle opening or running it pulls enough air to overcome the leak.The seal is a 1/4 wideX1/2 tall and 3 inches half that is part of the crankcase itself and holds the crank seal in place. I must have broken it while replacing the timing base last month, and didn't seat it properly. No way to fix properly without replacing the crankcase half. . Complete disassembly required if its even available...not doing that on a 20 plus year motor. Going to attempt to find an alternate method of retaining....

[Solarman]

Any chance a good welder could tack (heli-arc) weld a small lip back that could hold a new seal in place, maybe a thin large aluminum washer (far enough away to prevent new seal overheating). Just thinking outside the box. I know it's just a slight lip. I don't think the flywheel would hit, not sure if stator assy would have a problem?

Sorry this happened.
Good luck, post back on what you think.