2003 DT225 EFI Dual Spark plug coils

[baldbob]

Does anyone know if the dual spark plug coils on these motors can be tested. I replaced all 12 sparks plugs but still missing on a cylinder.or two.All cylinders come in at 120 PSI The coil has two spark plug wires going to each cylinder and is one piece There is no place other then spark plug boot to test I have Suzuki service manual not Seloc but I see no mention of coil testing. At $80 a piece with 6 coils, I'd like to verify before spending $500 Thanks

[Solarman]

There should be a coil test in the electrical section of the manual. Another way to test is using a timing gun that can be clipped onto each wire to show if it is firing by flashing like a strobe light. It may be difficult to tell if cylinder is missing sporadically. If you can identify which cylinder(s) are missing, swap plugs with other cylinders to see if problem is still the same cylinder. It wouldn't be the first time a couple of new plugs were bad from the store.

Are you certain it is electrical? You should also Test the gear counting coil by the book, as this sensor can miss-read and cause motor to run rough, add if it is skipping, mounting of this sensor is important to read the flywheel.

But the test section in electrical should tell you what ohms each side of the coil should be.

I was under the impression most motors after 2000 were 4 stroke, although I have run across a few DT's made/sold after 2000.

Good luck, post back on what you find out.

[Hoosmatroos]

I it possible to switch the coil with another cylinder? Then you can see if the problem is moving with the swap or not.

[baldbob]

Im not sure what cylinder is not firing. I'll put some rubber gloves on and start disconnecting spark plugs to see which one isn't firing. If idle isn't effected when I disconnect spark plug, I'll know its not firing. and replace that coil/plug.

[seaox230c]

the coils can be tested with a timing light but you have to take the plastic wrap off the basic spark plug wire a good coil will flash steadily any intermittent flashing is not good. you can swap coils easily enough to see if its a coil pack or something else