SwampThing
Petty Officer 2nd Class
- Joined
- Nov 6, 2006
- Messages
- 117
I have an 86 force 125hp on a 1986 Bayliner Capri Cuddy.
Prestolite ignition system. 2 CDI units, 4 ign coils.
I'm having a problem with no spark on the #1 plug.
Compression is good. All fuel system components have been cleaned, rebuilt, or replaced and set to specs.. Including the carbs and fuel pump.
The boat lacks power, especially at top end, and I can't get any kind of "hole shot". Rather it gradually increases speed.
The stator checks out with an ohm reading of 750 (spec 500-900)
Trigger wires check out at 48.9 on one and 51.5 on the other set. (spec 48-52)
Coils have the following readings:
All coil readings between the primary wires and ground have a reading of 0 ohms. I'm assuming the spec of 0.2 - 0.7 is to allow for the maximum allowable resistance to ground (ie, connections, corrosion, etc.) before the ground connection could become an issue. Note; A zero reading is not an O.L reading.
Coil secondary wiring readings would indicate the need for new plug wires. All reading are between 155 - 160. The spec calls for 120 -160. So the plug wires are at the higher end of spec but still should work sufficiently to fire the plugs. Although they are going to be replaced.
So what am I left with? The CDI unit? When I pul the plugs the #1 plug is completely clean like it just came out of the box. There is an amount of wet fuel on it though. The rest of the plugs show the normal carbon deposits.
The only strange thing is that I have put a timing light (Snap On brand with inductive plug wire pick up). Sometimes the timing light flashes and sometimes it doesn't. Rest assured there's nothing wrong with the timing light. But this doesn't seem to make sense since the plug looks like it's never fired at all.
Okay I'm fresh out of ideas. Before condemning a CDI unit I would like to be able to positively identify it as the source of the problem. Any suggestions?
Prestolite ignition system. 2 CDI units, 4 ign coils.
I'm having a problem with no spark on the #1 plug.
Compression is good. All fuel system components have been cleaned, rebuilt, or replaced and set to specs.. Including the carbs and fuel pump.
The boat lacks power, especially at top end, and I can't get any kind of "hole shot". Rather it gradually increases speed.
The stator checks out with an ohm reading of 750 (spec 500-900)
Trigger wires check out at 48.9 on one and 51.5 on the other set. (spec 48-52)
Coils have the following readings:
All coil readings between the primary wires and ground have a reading of 0 ohms. I'm assuming the spec of 0.2 - 0.7 is to allow for the maximum allowable resistance to ground (ie, connections, corrosion, etc.) before the ground connection could become an issue. Note; A zero reading is not an O.L reading.
Coil secondary wiring readings would indicate the need for new plug wires. All reading are between 155 - 160. The spec calls for 120 -160. So the plug wires are at the higher end of spec but still should work sufficiently to fire the plugs. Although they are going to be replaced.
So what am I left with? The CDI unit? When I pul the plugs the #1 plug is completely clean like it just came out of the box. There is an amount of wet fuel on it though. The rest of the plugs show the normal carbon deposits.
The only strange thing is that I have put a timing light (Snap On brand with inductive plug wire pick up). Sometimes the timing light flashes and sometimes it doesn't. Rest assured there's nothing wrong with the timing light. But this doesn't seem to make sense since the plug looks like it's never fired at all.
Okay I'm fresh out of ideas. Before condemning a CDI unit I would like to be able to positively identify it as the source of the problem. Any suggestions?