efi vs carb
 

hey guys just wondering if you know pros and cons on a 500 hp for a 29.im down to 2, one is carb and the other efi.To me i think the efi would be better but maybe im missing something

Efi.

Get the EFI. I just got a new boat, with 500EFI, it is sooo sweet, just turn the key and it starts, no priming the carb, no leaky gaskets. Definately go EFI.
Dave

Love my EFI's - so far. lol

500 Efi
 

The HP is a little stronger motor, but the EFI is turn key. No carb kits and easy starting. I'd go with the EFI.

EFI all the way. I remember one time my batteries were nearly dead at the boat ramp. The boat wouldn't even turn over on one battery and barely turned over on two. After 3 very slow rotations, the engine fired. Whew!!!

EFI -- not on a boat!
 

The problem with EFI is that all the signals go into the computer, and the computer then adjusts everything. If any of the signals are a bit wacky, the engine runs wierd. It is IMPOSSIBLE to determine the source of the problem from the symptom.

Teague could not do it. Paul Pfaff could not do it.

I eventually had Pfaff simply replace the entire wiring harness -- easily ordered from Mercury by the way. The harness plus installation cost about as much as 10 brand new Holley marine carbs, or a pair of new CMI headers.

Inspecting the old harness showed that a few pins in several connectors -- and different pins in different connectors between the two engines -- were corroded. This caused the signals going to the engine computer (fuel flow, air temp, knock sensor, etc) to either be slightly off or inconsistent. This also causes the controlling actions from the computer (throttle setting, timing, fule flow, etc) to be wrong or inconsistent.

After replacing all the wiring harnesses, the engines again run perfectly. My boat is only 7 years old. Some of the problems that have been fixed by the new harness were inconsistent problems that Teague and Pfaff were not able to fix for the past 4 years and tens of thousands of my dollars.

Right -- most of the time, my EFI engines have been giving me wierd little problems.

The total cost of all the attempts at fixing what was really due to corrosion in the wiring harness exceeded the total cost of two new 454 Magnum EFI engines.

With carburated engines, its very easy to figure out what is wrong. And hardly anything ever goes wrong, and if it does, its very cheap and easy to fix. Any idiot, even me, can fix it.

With EFI, you can't accurately isolate the problem, all the parts are very expensive, all are prone to glitches (sometimes its OK, sometimes its not) and the best mechanics in the industry may well not be able to fix it no matter how much money you throw at the problem.

EFI never again.

basicly it comes down to 2 things.

how you run

and your budget

if you run alot in ruff or big water at speed then i would say get the efi. their are no floats to get stuck and dump fuel, etc,,, .plus what was mentioned above as far asw starting. down side is cost for maintanance and repairs, plus if you get stuck at sea your stuck.

if you bay or lake bomb mostly and dont run in ruff water then get the carb. you can keep a spare coil, module, and a basic tool kit with you onboard and for the most part your getting home. cheaper maintanance , easier to diagnose repairs, more power, easier to upgrade performance.

either engine is strong. good luck with your search

I had stock efi's from the factory, but once I went to addtiional horsepower to me carbeurated was the only way to go. I can get anyone to work on.

Good thread.

I wouldn't be afraid of carb motors. Easy to work on as stated. I'd still go with EFI if price and condition is equal.

The HP500 has a whole lot more adjustability. My 98 29 was always sooting up the transom at idle. Was able to cut that out and get the idle I wanted.

Don't forget the valve springs. The pre-2001 HP's needed to have the valve springs replaced after about 200 hrs. Not sure if that continued after 2001 untile Merc went to 525s.

Also, I remember having to get new caps and rotors once a season.

So a little bit more maintenance for HP500, but they were bullet proof in my 29 and 35. I really dislike the different idle RPM for the 525s on my current boat . Supposedly not adjustable...but that's my only complaint.

How Long Ago Was This Problem?
 

Respectfully, if they don't alreay have it, your guys should have owned and had the experience to properly use the CDS SmartComm System. It's terrible that guys like you (and there are lots) have had to go through such an expensive endeavor only to go back in time and be extremely dissapointed. I am not at all defending either side of efi or carb. We all "like" what we like. It's a shame that most of the techs and lots of service depts still have not invested in the successor to the DDT and the "old school" troubleshooting techniqs. It's very good to be old school but they also need to catch up a little. The CDS would have found your issues in micro seconds (with the right guy using it) as it is wise to corrosion and the effects of corrosion in relation to the ecm. I say efi but I also say that a lot of us as owners are going to have to start making an investment in learing as much as we can and buying some of the higher end tools because as time goes by and the dying breed of "real marine mechanics" fades away, we're all left to live your nightmare all over again. You would be absolutely amazed at how much easier it is to fix a computerized efi engine with a computer! That's not to say that fixing boats is any less cumbersome than it used to be but things are changing fast. The good marine tech can no longer go soley off of what he's learned thus far. He needs to learn the future of these powerful and very sophisticated engines... I bought a system and am slowly learning how to use it. My learning curve is huge on this stuff but it's fun to learn and I will continue to learn and share my experience with anyone who can use it and hopefully it will come back in circle. Sorry for the long post but I know EXACTLY how you are feeling. I've lived it. Take care.

Long live the beak - -

I can't say enough about the 500efi's in mine. They are at about 250 hrs but they run like a dream. I just had to have the spring replacement / drive alignment maint done and ouch. Nothing can be any more turn key performance as those efi's. If you can afford the boat with them, then just suck it up and pay for the maintenance from a reputable merc mechanic and enjoy the fruits.