1997 Mercury XR6 150 no spark 1 and 4 cyl

[MercuryXR6]

I have a 1997 Mercury XR6 150. I was using the boat Tuesday night and engine was running fine. On Wednesday morning, I couldn't get plane. The boat had no power. I changed all the plugs, the same. Today I did compression test 128 all 6, but no spark on #1 and #4, 2 different banks. I changed the coils on 1 and 4. Still no spark on 1 and 4. Any suggestions!!!

 

[j_martin]

Re: 1997 Mercury XR6 150 no spark 1 and 4 cyl

I have a 1997 Mercury XR6 150. I was using the boat Tuesday night and engine was running fine. On Wednesday morning, I couldn't get plane. The boat had no power. I changed all the plugs, the same. Today I did compression test 128 all 6, but no spark on #1 and #4, 2 different banks. I changed the coils on 1 and 4. Still no spark on 1 and 4. Any suggestions!!!

The common part for cylinders 1 and 4 is the trigger. The trigger has 3 coils in it, each drives a pair of cylinders opposite in the timing sequence.

Check the trigger connections on both 1 and 4 at the switchboxes. Pull and push on the wires feeling for a loose or broken wire. If they both are good and clean, then disconnect them and measure the resistance between them with an ohmmeter. It should be between 1100 and 1400 ohms. Either lead should be infinite (open) to ground. If it's bad, replace the trigger.

hope it helps
John

 

[MercuryXR6]

Re: 1997 Mercury XR6 150 no spark 1 and 4 cyl

Thanks for the quick reply. Looks like the trigger coil is the problem. I did a check using chart: Br to P 1148 ohms, P to W 1148 ohms, W to B 1 ohm. 1 part of the coil is not working. Will order a part and try. Thanks again

 

[j_martin]

Re: 1997 Mercury XR6 150 no spark 1 and 4 cyl

Thanks for the quick reply. Looks like the trigger coil is the problem. I did a check using chart: Br to P 1148 ohms, P to W 1148 ohms, W to B 1 ohm. 1 part of the coil is not working. Will order a part and try. Thanks again

Don't forget to do a link n sync when you put in the new trigger. It will affect the timing. Don't wreck a good motor with half a job.

hope it helps
John

 

[MercuryXR6]

Re: 1997 Mercury XR6 150 no spark 1 and 4 cyl

How do I link n sync? I was going to take a pic of the existing set-up prior to removal and install the same way and mark all the wires. Howard

 

[j_martin]

Re: 1997 Mercury XR6 150 no spark 1 and 4 cyl

How do I link n sync? I was going to take a pic of the existing set-up prior to removal and install the same way and mark all the wires. Howard

Get a service manual. There is a procedure to check flywheel timing, and then set up all your linkages and ignition timing for proper operation. When that's done the only adjustment left is idle speed , which is done at the lake.

It's a little intimidating at first, but after you do it once it makes complete sense. When you get into the trigger, you're also into the linkages, and timing will change. If you don't set it up right, best case is a poorly performing engine. Worst case is a grenaded power head.

Swapping parts don't make you a mechanic. A little education can, though.

hope it helps
John

 

[MercuryXR6]

Re: 1997 Mercury XR6 150 no spark 1 and 4 cyl

Your diagnosis was bang on. The part was replaced and the engine runs better than ever. Thanks again.

Howard

 

[j_martin]

Re: 1997 Mercury XR6 150 no spark 1 and 4 cyl

Did you do a link and sync, or are you going to hope it doesn't grenade?

John