2 dead cylinders

[dsujen]

I have a 1986 110hp vro mod.#e11omlcdc ; ser.#r1308421.
Ran good in the yard the night before i took her out. I start it up at the dock and no wake cruise passed the no wake zone and go to accelerate and it grumbles and barley moves at full throttle. I stumbled back to dock and took out the tool kit. 2 cylinders on the same side were not firing. The heads on that side were cold to the touch and the plugs were fouled. The dead cylinder plugs' center pin was shaped at an angle instead of being flat. Almost as if I filed the point with a file at about 30 degrees. I installed a set of clean but used plugs for just such an emergency but there was no difference. I started it up and in nuetral it would get to about 2000 rpm wide open. I cleaned the coil ground straps and checked the connections going to that side of the engine for the most part. Still no go. I don't think it's the coils cause what are the odds of 2 coils failing at the same time? Can any one help me fix the problem? 2 weeks before it sat in the yard she ran great for 2 years.

 

[HighTrim]

Re: 2 dead cylinders

1. Check the stator and trigger resistance and DVA output as given below for both banks:

Wire Color: Check to Wire Color: Resistance : DVA Reading

Brown wire :Brown/Yellow wire: 450-550: 150V or more Connected
White wire: Blue wire: 38-42: 0.6V or more Connected
White wire :Green wire :38-42: 0.6V or more Connected

NOTE: Also check the DVA readings to engine ground from each brown wire and compare the readings. If one wire reads low while connected to the pack, swap the connections and see if the low reading stays on the same stator wire. If it does, the stator is bad.
2. Check the DVA output on the orange wires from the power pack while connected to the ignition coils. You should have a reading of at least 150V or more. If the reading is low on one cylinder, disconnect the orange wire from the ignition coil for that cylinder and reconnect it to a load resistor. Retest. If the reading is now good, the ignition coil is likely bad. A continued low reading indicates a bad power pack.

 

[dsujen]

Re: 2 dead cylinders

Is there an easier way to test this for someone with minimal tools and know how?

 

[Solittle]

Re: 2 dead cylinders

I would check the compression also. The damage to the one plug is bothersome.

 

[dsujen]

Re: 2 dead cylinders

It's both plugs on the dead cylinders.

 

[HighTrim]

Re: 2 dead cylinders

Check the compression as stated. Without testing equipment, swap the coils, if the problem follows the coils, replace them. The power packs are interchangeable, swap them next to see if the problem follows. Let us know what you find.