- Yamaha 115CETO (model 6N6), 2-stroke, 1996
- CDI-box on starboard side, below rectifier
- Red wire from engine tank oil sensor NOT connected to CDI-box via R/L - wire BUT to pink (P) termosensor wire, via a 1" cylindrical component, seemingly a diode, blocking current from oil sensor to termosensor pink wire ?
- NO ground (grey/black) from termosensor wire to trim sensor's grey cable (as some electrical diagrams shows)
- NO remote oil tank
- NO gauges
- Trim sensor SHOULD NOT be connected, but loose end, BUT turns out to BE CONNECTED to Y, Y/R, G, G/R 4-pole wire , supposed to go to oil alarm/meter EDIT: before, bold text "oil alarm/meter" said "trim meter"
Storyline:
1. Engine overheats at 3/4 WOT. Alarm triggered BUT (at least as the engine's user told) NO rev. limiting !
2. Engine taken to authorized Yamaha work shop. Impeller shown to be OK, but changed. High pressure water cleaning of lower unit. Now "only" overheat alarm at 4/4 WOT.
3. Taken to work shop second time to "clean jackets" under cylinder heads. Seems the thermosensors not changed. If thermostats changed, I don't know (not me being in contact with work shop). NO improvement of overheat alarm.
4. Shortly after being to last repair, engine begins to stop abruptly, intermittently, to finally after some weeks, quitting totally.
5. I see the engine first time. NO sparks. NO voltage output from CDI-box (DVA-measurement) with kill-switch disconnected. Charger- and pulser-coils within specs. both ohm and voltage. NO contact to ground. Ignition coils ohm-measuring OK.
6. Remarkable finding : the Y, Y/R, G, G/R 4-pole wire from oil unit is connected to trim sensor (orange, black, pink; gray lose end) !!!!!
Question:
Could these misconnected wires be the reason for the CDI-box failure?
Could it have been misconnected before the work shop visit?
If so, could that misconnection be the reason for the rev. limiter NOT kicking in at overheat alarm?
If else, what could have caused this sudden onset random non-spark firing and final death of sparks?
Those intermittent, and then final failures of CDI-boxes, can it be caused by simply a soldering inside the box getting loose, stirred by vibrations, causing the intermittent behavior, and then finally getting loose totally ?
Very much tankful for input from mechanics/autodidacts with understanding of what's inside the oil unit and the CDI-box.
Thanks in advance !
- CDI-box on starboard side, below rectifier
- Red wire from engine tank oil sensor NOT connected to CDI-box via R/L - wire BUT to pink (P) termosensor wire, via a 1" cylindrical component, seemingly a diode, blocking current from oil sensor to termosensor pink wire ?
- NO ground (grey/black) from termosensor wire to trim sensor's grey cable (as some electrical diagrams shows)
- NO remote oil tank
- NO gauges
- Trim sensor SHOULD NOT be connected, but loose end, BUT turns out to BE CONNECTED to Y, Y/R, G, G/R 4-pole wire , supposed to go to oil alarm/meter EDIT: before, bold text "oil alarm/meter" said "trim meter"
Storyline:
1. Engine overheats at 3/4 WOT. Alarm triggered BUT (at least as the engine's user told) NO rev. limiting !
2. Engine taken to authorized Yamaha work shop. Impeller shown to be OK, but changed. High pressure water cleaning of lower unit. Now "only" overheat alarm at 4/4 WOT.
3. Taken to work shop second time to "clean jackets" under cylinder heads. Seems the thermosensors not changed. If thermostats changed, I don't know (not me being in contact with work shop). NO improvement of overheat alarm.
4. Shortly after being to last repair, engine begins to stop abruptly, intermittently, to finally after some weeks, quitting totally.
5. I see the engine first time. NO sparks. NO voltage output from CDI-box (DVA-measurement) with kill-switch disconnected. Charger- and pulser-coils within specs. both ohm and voltage. NO contact to ground. Ignition coils ohm-measuring OK.
6. Remarkable finding : the Y, Y/R, G, G/R 4-pole wire from oil unit is connected to trim sensor (orange, black, pink; gray lose end) !!!!!
Question:
Could these misconnected wires be the reason for the CDI-box failure?
Could it have been misconnected before the work shop visit?
If so, could that misconnection be the reason for the rev. limiter NOT kicking in at overheat alarm?
If else, what could have caused this sudden onset random non-spark firing and final death of sparks?
Those intermittent, and then final failures of CDI-boxes, can it be caused by simply a soldering inside the box getting loose, stirred by vibrations, causing the intermittent behavior, and then finally getting loose totally ?
Very much tankful for input from mechanics/autodidacts with understanding of what's inside the oil unit and the CDI-box.
Thanks in advance !
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