Merc. 200hp Starting issue.

[Mullady76]

I took the boat out for the first this year and I had some problems getting the engine re-started after it warmed up.  I would have to crank it over for a long time, and after 10 tries it would sputter and finally start. I also needed to open the throttle all the way to get it to start.  I don't think its a fuel problem because it relatively new (treated) fuel, brand new water separator, and fuel lines. However I will change the filters and check the fuel pump anyways.  The motor is a 1998 Mercury 200hp 2 stroke (carb'd.).

When I research the symptoms, I keep hearing about the stator and/or power packs going out.  Has anyone had this problem before?  These parts are expensive and non returnable.  I don't want to throw money into something that wont fix the problem.

Thanks, Sean

[wingtime]

When was the last time the carbs were cleaned?

[Mullady76]

When was the last time the carbs were cleaned?

I've had the boat for 3 years and have touched the carbs. I do decarb the motor & clean the carbs with Seafoam using DUNKS method of 1 gal. of gas to 1 can of Seafoam.  This is done every year.

[fitz73222]

Mullady,
First, give me your engine serial number. I'm pretty sure your engine has the much improved ignition system using the coil amplifier design that eliminated the switch box design, in other words, each coil has its own CD module so that's a good thing. The key to this is that you had a hard start issue after the engine had warmed up which points to a stator or trigger. Now if the stator is bad we can go with a CDI brand stator which has a warranty. I don't use Mercury stators anymore because there is no warranty and they are high priced. How did the engine start when it was cold? How did run up until you shut it off and then attempted to restart? Did it miss or shut off anytime while it was running? It sounds like you take care of this engine. I always recommend trying to run the engine on a remote 6 gallon tank with fresh fuel to eliminate the boat's fuel system if it is suspect. But let's start with basics.

[Mullady76]

fitz73222, I can give you the serial number later on tonight after I get home from work.  It took 2 or 3 cranks and some throttle to start the engine when it was cold, which it always has.  The motor ran great before I shut it down, no stalling or misses. 
After I got the motor re-started I noticed it was sluggish between 1500 to 2500 rpms, but ran fine once I was up on a plane.  No stalling or missing whatsoever so I kept it running for the rest of the day.  Before heading home I shut it off to see if it would start and it did the same thing.
Thanks, Sean

[Mullady76]

The more I research this problem the more questions I have.  I saw this mentioned in a few post over at the S&F.  Some people say this charging system doesn't work well with AGM batteries.  Earlier this year I replaced my 5 year old lead acid Interstate batteries for a set of Duracell AGM's.  Hopefully this didn't cause the problems I am having?  If this truly is the problem can I swap out the starting battery to a lead acid and use the ARC to charge the larger AGM house battery?

[fitz73222]

Sean,
The ignition and charging systems are completely independent of one another except for the fact that if the charging part of the stator runs hot It may start to have an effect on the ignition side since they are podded together. Don't know about the AGM batteries and the relationship with ignition systems. Your engine will run without a battery since it generates its own ignition voltage once it obtains 300 rpms during cranking so the battery is irrelevant.

[Mullady76]

Fitz, the serial number on my engine is 0G594150.

[fitz73222]

Well Sean,
Based on serial number your engine has the old style switch box ignition system, are you sure it's a 98?

[Capt. Bob]

The more I research this problem the more questions I have.  I saw this mentioned in a few post over at the S&F.  Some people say this charging system doesn't work well with AGM batteries.  Earlier this year I replaced my 5 year old lead acid Interstate batteries for a set of Duracell AGM's.  Hopefully this didn't cause the problems I am having?  If this truly is the problem can I swap out the starting battery to a lead acid and use the ARC to charge the larger AGM house battery?

Sean,

Not sure what you are reading on the other site but I'm thinking that when you see "doesn't work well" they are referring to the motor's charging system's ability to furnish a "correct" charge to a specific type (in this case an AGM) battery. Lead acid batteries have been the norm for many years and outboard charging systems are (and I'd venture to say, still) geared toward this type of battery. Gel and AGM are different technology and as such, do require a different charging algorithm (think "smart chargers").

Funny how this all works but I digress.

That stated, your problems are more than likely not caused by the battery type. As Fitz noted, the motor relies on the battery to break its inertia and get it spinning to an rpm that will allow it to function under its own power generating system. The charging system of your motor may not supply a newer type battery with the exact designed recharging "voltage steps" but I've found this not to be a problem short term. Proper charging while at rest (on the trailer in the yard) will (again just my personal experience) charge your AGM and keep it healthy. Again, what my research has found is that modern AGM batteries handle a charging  pattern resembling a lead acid type and are less susceptible to "incorrect charging" that one will find on most outboard systems. I have replaced one gel type with an AGM based on my findings. Still, I have had superior performance (and continue to) from my gel type but costs, additional cranking amps per size and the above mentioned "less particular" to low tech outboard charging systems, I'm moving to the AGM type.

 I would not be so quick in switching back to a lead acid. This is not the root cause of your problem IMHO.

Good luck.

[Mullady76]

Fitz, Yup its a 1998 model that was manufactured in 97. Here a picture of the tag.

[fitz73222]

Sure is, anyway it has the old style switch box ignition. How long does the engine have to sit before it becomes hard to start after you have run it? 20 minutes, 1 hour? Does it start right up and die? Have you ever tried just bumping the choke and then try to start it? This is not unique to your engine. I'm assuming your engine always started right up after sitting and this is something new?

[Mullady76]

Every time it happened the motor was shut down for maybe 5 minutes max.  No, it didn't start right up and die, just cranked and cranked a cranked.  When it finally started, it sputtered and smoked for a second, then revved up because the throttle was almost all the way open. Once it was running it idled perfectly fine.  Yes, I tried using the choke or fuel enrichment circuit by pushing the key in for a few seconds.  Last season the motor would re-start with a quick bump of the starter.

[fitz73222]

Sean,
Is your treated fuel, non-eth, E10 or E15? Not sure what is available in your neck of the woods. How old is relatively new treated fuel. If your engine had an ignition system issue it should be affecting running quality which it sounds like it is running fine, once started. Has anyone adjusted the base idle timing, idle speed; what is it? Or any throttle pick up adjustment? Mercury's in general can be quirky when it comes to base adjustments. Has the throttle cable been replaced? The cable preload must be set correctly against the idle stop and throttle pick adjusted. This is not uncommon for a Merc to start cold fine and be hard to start warm and in many cases, it needs to be linked and sync'd to original specs and the are very specific.

[Mullady76]

The fuel is 93 octane E10 from last fall, treated with stabil for storage. It was top off with 10 gallons of fresh fuel the week before I had issues with it.  All the cables to the motor were remove to replace the rigging tube, but the adjustments weren't changed. The carbs have not been touched. Yes it runs fine in the upper RPMs and idles fine. It just struggles between 1500 & 2500.
I ordered a dva adapter for my multimeter and will check the stator and power packs out. If everything checks out I'll move to the carbs.
Thanks, Sean