A Few Questions From a New Boat Owner!

We just purchased a '92 Sea Ray with the 3.0 Mercruiser (4 cyl). I'm having a little work done to it, so while I am passing the time, I am trying to learn what I can about these boats. I've always been a "car" guy, so I gravitated to the inboard because of the relationship to the GM 4 cyl. I do have a couple of questions about performance stuff to do.
I don't want to dig into the engine, I understand that there's not much to be gained from that, and if it doesn't need rebuilt, I don't want to mess with it. What I was looking at is on the ignition side. I noticed right away, that it's a typical GM ignition with the remote coil and newer ignition module. I want to upgrade the coil, and I was thinking of doing the ignition module, but is there really any benefit to that? Also, what about an ignition box like an MSD or Accel? Is there a benefit in a boat application? I know that I'm not looking for power increases as much as I am a smooth idle and easier starting.

Re: A Few Questions From a New Boat Owner!

Welcome aboard!

With the rpm limited range that a boat operates in, and the stock compression of the engine, you will see no noticeable improvement on performance with any aftermarket ignition systems or amplifiers. Spend your money on more gas for fishing and cruising!

Re: A Few Questions From a New Boat Owner!

I think as far as starting goes it is all going to be if your choke still functions on your carburator. I also have a 92 mercruiser V6, starting stinks but I am sure my choke doesnt work properly. After i pump it a few times and let it warm up there are no issues the rest of the day.I would be careful putting and "Car" ignition stuff on the boat due to corrosion and other issues including open spark.

Re: A Few Questions From a New Boat Owner!

That's good advice!
It is true about the limited RPM range, these top out at 4800 RPM, correct? If that's the case, the factory ign. module is definitely good enough, those don't fall off until over 5K RPM. I may still go with a coil though, those benefit any engine up to around that 5K range without using an ignition amplifier.
Other than a prop change, what else can be done to squeeze a little bit more out of this engine?

Re: A Few Questions From a New Boat Owner!

what else can be done to squeeze a little bit more out of this engine?

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Ayuh,..... Welcome Aboard,.... Other than cuttin' a check for a boat with a Bigger motor,.... Nothin'....

Do the maintenance, keep the fluids fresh, Tune ups, 'n clean gasoine is 'bout all ya can do...

It takes 'bout 20 hp to see a Noticeable improvement in most any boat,...

There ain't another 20 hp in a 3.0l motor...

Re: A Few Questions From a New Boat Owner!

dwelf said:

I think as far as starting goes it is all going to be if your choke still functions on your carburator. I also have a 92 mercruiser V6, starting stinks but I am sure my choke doesnt work properly. After i pump it a few times and let it warm up there are no issues the rest of the day.I would be careful putting and "Car" ignition stuff on the boat due to corrosion and other issues including open spark.

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Do you have the 4bb carb or 2? I have a 4bb on my 1995 V6 and was having a horrible time trying to get it started when cold. Turns out the carb wasn't choking when I had the throttle linkage pushed all the way forward. Would never have known if someone wasn't watching the carb while I was trying to start up. So it's nearly impossible to cold start when the throttle is all the way forward, but when it's about 2/3 to 3/4 forward it fires right up. Might be worth looking at.

Re: A Few Questions From a New Boat Owner!

rodgeml1 said:

Do you have the 4bb carb or 2? .

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He has the 3.0L, not a V6, and there is no option for a 4bbl on 3.0L engines. Way too much carb for a 3.0L

Re: A Few Questions From a New Boat Owner!

Also keep in mind, unlike a car, ANYTHING that has potential to create a spark on a boat MUST be ignition protected. (Ignition components, alternators, starters, etc) Gasoline vapors sink, so any gas vapors build up in the bilge and if you have a non-ignition protected part that creates a spark...boom.

Re: A Few Questions From a New Boat Owner!

Don S said:

He has the 3.0L, not a V6, and there is no option for a 4bbl on 3.0L engines. Way too much carb for a 3.0L

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My response was to Dwelf regarding his V6. Sorry....I should've been more clear about to whom I was speaking.

Re: A Few Questions From a New Boat Owner!

The fuel thing is a good thing to keep in mind! It has a blower, but all it takes is one time of not turning it on. I have heard horror stories about fuel and inboard motors, and I'm a worrier any way, so I'm sure it will be triple checked for deficiencies any time I take it out.

Re: A Few Questions From a New Boat Owner!

Okay, we've had her back for about a week now and been on the water 3 times. The outunit is working great (that's where the majority of the work was needed), and the engine runs good.
The first time we took it out, it had two-year-old gas in it. It ran, but very rough and it was hard to start. The next time, I had filled the tank with new gas (non-ethanol) and sea foam. It ran AWESOME. We were able to hit 36mph on calm water without a problem. The last time we had it out, it was back to a rough idle and hard starting, with some bogging when going to full throttle. I had to keep adjusting the carb mixture screw to get it to run good.
Would this just be a gas issue? I have replaced the plugs, wires, cap and rotor (still had the factory cap/rotor). Or, would this be something more, like a carb rebuild?

Re: A Few Questions From a New Boat Owner!

SilverBulletZ said:

Okay, we've had her back for about a week now and been on the water 3 times. The outunit is working great (that's where the majority of the work was needed), and the engine runs good.
The first time we took it out, it had two-year-old gas in it. It ran, but very rough and it was hard to start. The next time, I had filled the tank with new gas (non-ethanol) and sea foam. It ran AWESOME. We were able to hit 36mph on calm water without a problem. The last time we had it out, it was back to a rough idle and hard starting, with some bogging when going to full throttle. I had to keep adjusting the carb mixture screw to get it to run good.
Would this just be a gas issue? I have replaced the plugs, wires, cap and rotor (still had the factory cap/rotor). Or, would this be something more, like a carb rebuild?

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Does it run well once you get up in the upper throttle ranges? If so, have you checked the timing since you replaced the cap and rotor. Sounds like a timing issue to me.

Re: A Few Questions From a New Boat Owner!

Do you have a fuel / water separator? If not, go ahead and install one. I would suggest pulling the top off of the carb at the very least and looking to see if you have debris / water in the bowl. Also replace all of your filters.

Re: A Few Questions From a New Boat Owner!

It does run good in the upper RPM ranges. It was bogging a little if I went to full throttle quickly, but not too bad. I did forget to mention that it would run-on every once in a while when I shut it off.
I haven't checked the timing, but I am going to check it this weekend. It's 1* ATDC, correct?
With the fuel and filters, where are the filters? I found what looks like a sediment bowl under the fuel pump, but no filters anywhere. Also, where is a good place to get the filters?
With a fuel/water separator, what's the best way to put that in?

Thanks everyone!