Mercury 200 Pro XS V8 issues

[fuelleak]

My partners new 2020 200 V8 (serial # 2B741447) has been a total let down. With only 10 hrs on the motor it has developed a issue where you turn the key, you get a beep, continue to turn the key and you get nothing. Sometimes if you keep turning the key it will suddenly fire. after waiting 3 weeks to get an appointment at a local Merc dealer, the dealer could not figure out the issue but put in a new ignition switch out of desperation which actually worked flawlessly for one day but then the issue has started again. Last Sunday in a tournament after testing it the day before and it acting reliable, we headed down the lake at take off and the motor started to miss horribly. We said screw it and we fished taking our chances getting back. Motor started fine as we went from spot to spot and the miss seemed to subside. That was until it was time to go, turn the key and nothing. Partner turns key like 30 or 40 times and it fires. 20 mile ride back in 3 footers with engine missing horribly we make it. We turned engine off at the ramp and now it will not fire. We are in Vermont and boat was bought in Georgia. Cant get 2nd appointment anywhere till August 5th. Georgia dealer has no answer except to get Merc involved which the first appointment did. Merc was clueless too according to that dealer. Willing to drive this boat pretty much anywhere to get this resolved. Any guidance would be appreciated.

[NWStratos]

Does he have a Smartcraft or Mercmonitor gauge or a Vesselview mobile app hooked up so he can read any fault codes ?

[EuropeanAM]

I would be starting at the BATTERY and BATTERY CONNECTIONS.

975 or higher CCA Batter (AGM REQUIRED). Prefer using clamp-posts, install ENGINE cables first, remaining lugs Largest to Smallest, and finish off the connection with a Stainless NUT or Locknut. DO NOT use wing-nuts.

CLEAN POWER harness must be on the cranking BATTERY, and secured to the battery or hold-down so that it is not slapping around. Loss of clean-power will cause ALL SORTS of problems.

Also disconnect and reconnect the 14 pin harness at the engine (to make sure it's properly attached).

Check battery cable connections INSIDE the cowling (right at the front of the engine). Make sure the cable does not move on the securing hardware (loose cables here can cause both complaints).

As for Merc- with the utmost of respect intended, they do not have a "crystal ball" that tells them what the problem is. They must rely on trained and tooled DEALERS in the field to be their Eyes, Ears and Hands (in many cases, their advice can only be as good as the "data" they are provided).

[fuelleak]

Tankyou Don, Ill forward all this information to my partner. We will go through that list. He has a Northstar 31 Agm so know the battery is up to snuff.

[Wannabfishin]

I would have agreed on battery or ignition. With the rough idle I would have to say the problem is much worse than that. Check the water separator, plugs too. Possibly battery and plugs? You may be having multiple problems possibly that is throwing everyone off. Since your unable to get into a dealer or Merc mechanic just try the simple things just in case.

[fuelleak]

Wannabfishin, no rough idle, just heavy missing while under way. Will pull plugs but why the no start? Why is it the ignition switch does nothing so often? I think Dons suggestions are a great starting point. Im praying its something like the clean power harness or a corroded pin in the main. My partner is certainly tired of this scenario and this $57K paperweight sitting in his barn.

[fuelleak]

Don, went through your check list and everything seems as it should be. What my partner just found out though is that he hears a clicking sound coming from the motor when he turns the key. Could that sound help you diagnose anything. Waiting for his wife to get home so she can turn the key and he can pinpoint it better. UPDATE: Seems to be coming from the bigger module under the big connector.

[EuropeanAM]

Those sounds are normal- when the PCM Wake signal is sent from the key-switch, the PCM wakes and closes the MPR, parks the throttle plate and shift actuator in correct positions, etc.

Dealer needs to try a separate harness on the engine to see if it resolves the problem (quick/easy way to determine that the problem is INSIDE the cowling, or in the keyswitch harness/boat wiring.

[fuelleak]

Got to say thanks for your help on this one Don. Will be giving this all to the dealer.

[Triton19x2]

Subscribed to this thread. Mine did this the other day on the first key turn but not again. Thought it odd and maybe I did not turn it far enough. Keep us updated and hope you get it resolved quickly.
Thanks

[marshall256]

Another possibility (but doesn’t explain the miss) Mercury had a recall on shift solenoids. If your shift solenoid is bad, it could cause the system to assume you have the engine in gear and will not allow it to start. Although, on mine I knew I had a problem because the engine would spontaneously shift out of neutral and into forward without me touching the gear shift. Mechanic said if I had let the problem persist it would have gotten bad enough that the scenario I mentioned on not cranking would happen.

My engine was outside of the affected recall batch, but oddly enough it had the older problematic shift solenoid.

[1Holeshot]

Another possibility (but doesn’t explain the miss) Mercury had a recall on shift solenoids. If your shift solenoid is bad, it could cause the system to assume you have the engine in gear and will not allow it to start. Although, on mine I knew I had a problem because the engine would spontaneously shift out of neutral and into forward without me touching the gear shift. Mechanic said if I had let the problem persist it would have gotten bad enough that the scenario I mentioned on not cranking would happen.

My engine was outside of the affected recall batch, but oddly enough it had the older problematic shift solenoid.

Chris, you have a pm.

[EuropeanAM]

Another possibility (but doesn’t explain the miss) Mercury had a recall on shift solenoids. If your shift solenoid is bad, it could cause the system to assume you have the engine in gear and will not allow it to start. Although, on mine I knew I had a problem because the engine would spontaneously shift out of neutral and into forward without me touching the gear shift. Mechanic said if I had let the problem persist it would have gotten bad enough that the scenario I mentioned on not cranking would happen.

My engine was outside of the affected recall batch, but oddly enough it had the older problematic shift solenoid.

Not solenoids. Shift ACTUATORS- and that was a select group of engines MUCH earlier in production than the OP's engine.

Low voltage or inadequate voltage/amperage can result in poor running characteristics AND Engine Guardian (which will feel like a "skip" if you are attempting to exceed the Guardian Threshold set by the PCM).

Address the starting problem FIRST (which is the OBVIOUS problem), once that is corrected, see if there is some "obscure" item remaining to be addressed.

More often than not- addressing the "obvious" problem solves other complaints.

[fuelleak]

Again, thanks Don. Goes into the dealer on the 5th.

[fuelleak]

Marshal 256, thanks for the input. Will give the info to the mechanic. Would it go in and out of gear nicely if the shift selonoid was bad because when this boat is running it shifts smoothly.

[EuropeanAM]

Don't send your dealer looking for non-existent items. There are no "shift solenoids".

[Savage]

I would be looking to see if the battery is undersized.

[fuelleak]

Savage, its a brand new Northstar AGM 31. Dont think there is a better battery!

[EuropeanAM]

Gary- just for this purpose, don't fall into the "it's new, it must be good" trap. A load test can confirm that it's the best of the best.

Also confirm that the Engine Cables, Clean Power, and Charger are all on separate CLAMP style terminals (use the battery's threaded lugs for everything else).

Connections at the engine end are just as important (and there is no guarantee that they are clean/tight unless they are checked/inspected).

[Savage]

Agree. If I were working on this problem the FIRST thing I would do is load test the battery!