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Older-era Carburetor and Modern-era Direct-injection Outboard Engines
|Author||Topic: Older-era Carburetor and Modern-era Direct-injection Outboard Engines|
posted 06-12-2015 02:28 PM ET (US)
Our new boat is equipped with a timeless carburetor engine by Yamaha, 1999 V6 200-HP. Overall performance is very good; there is very little smoke for a carburetor. It is not that loud either, but then there is the exhaust smell at low and idle speeds. Also I have noticed very poor performance in how it consumes fuel at low speeds. I have been accustomed to newer direct-injection engines that are quite the opposite. Their fuel management system is brilliant in how it saves gasoline at low speeds.
Is it safe to say [high fuelc comsumptin at idle speed] is normal of an engine of this era or could there be a problem with a certain part or component system in my motor? My boat fuel economy is in the range of 2-MPG at cruise, but, if I include running time--especially from the dock at low speeds--then the MPG would be far less, by my calculations ando bservations. Sadly, we happen to need about 15-minutes just to get out the marina and 15-minutes to get back in. I need to somehow calculate what that burns, but my guess is it is substantial. If we were to go out more than a few times a week, I have to say then we are adding up the fuel bill cost of ownership on this commute.
We all can give our inputs on the advantages and disadvantages of purchasing newer modern motors until now I can say this would be one large advantage to the list for buying a new engine for those who are contemplating it. I see why the E-TEC would be a good choice in this regard. My 2007 Optimax was really good for this as wellm but the E-TEC would be nice balance for everything.
posted 06-12-2015 05:16 PM ET (US)
Direct-injection is better than carbs for fuel usage and adjustment but require more high-tech parts. Carburetors are more dependable but use more fuel. Yes, I would go for a new Evinurude if you plan to get a new engine.
posted 06-14-2015 08:19 AM ET (US)
Older two-cycle engines waste a lot of fuel at lower engine speeds. At low engine speeds, the E-TEC engine uses stratified mode combustion. That is the key to its great fuel economy. My 3.3-liter V6 E-TEC can run about five hours on one gallon of fuel at idle speeds. Its old-fashioned cousin would consume much more fuel at idle, probably several gallons per hour.
posted 06-14-2015 08:49 AM ET (US)
I would like to make a statement regarding reliability of 2 stroke engines, some 2 strokes that is. I have never had a direct injected or fuel injected 2 stroke but feel that in some instances they are receiving an unfair reputation over two strokes when it comes to reliability.e. every two stroke I have ever owned has been what I consider very reliable and at a very low maintenance cost. The 70 hp evinrude on the old sport 15 I had growing up was used and abused on a daily basis with little to no fuss in the area of maintenance. The current 60 degree v6 on my outrage 19 is an even better performer than the old 70 was. I've never had to take either motor for special tuning or diagnostics. From what I understand there are many more complications that could occur on today's modern 2 and 4 stroke engines.
posted 06-14-2015 10:20 AM ET (US)
Direct and port fuel injected engines are incredibly reliable and require virtually no fuel system maintenance. Good fuel filtration seems to be the key to long service life.
Carbureted engines are much more demanding of maintenance and adjustment particularly in multiple carburetor applications. Things like mixture adjustment, jet cleaning, float level settings, throttle linkage adjustments and periodic removal for cleaning and overhaul are not required with injection systems.
We can quibble about the details but almost no modern engine uses carburetors.
posted 06-14-2015 10:58 AM ET (US)
I think people have long forgotten how simple and everlasting some of the old two-stroke engines were and are. I have had only one carburetor overhaul on my 1998 Johnson 150, and that was after a long three-to-four-year storage layup which was not planned and poorly prepared for. Even in that case the return was more preventative than mechanical necessary. I'm sure the new high tech engines are wonderful, but, please, do not impart undo prejudice against the simplicity of the old carberurated two-cycle engines that had served the industry so well for so long. As compared to some of the old two-cycle engines, the new systems are still in their infancy. In fact I'm wondering if they will be as long lasting as some of the older two-cycle engines. Take the three-cylinder loop-charged OMC engines--they were great as were their Yamaha clones.
posted 06-15-2015 08:35 AM ET (US)
In moderate air temperatures, and when running at optimum throttle settings, an older two-cycle engine with carburetors is a nice engine. I used to have a classic OMC two-cycle engine with six carburetors. In the typical weather in which you want to go boating as recreation, the engine started very reliably, with very little cranking. The engine ran smoothly, and provided outstanding power and acceleration. If a high-quality, low-ash, premium lubricating oil was used, there was minimal smoke in the exhaust. The 1992 Evinrude 225-HP V6 3-liter engine was running just like a new engine when I sold in in 2009. It was 17-years old. The replacement parts were limited to electrical parts (Powerpack and Rectifier-Regulator assembly) and several water pump kits. The oil mixing system fuel pump was due for replacement, mainly from the effects of ethanol-gasoline blended fuel. Other than those components, the rest of the engine--block, heads, pistons, bearings, reeds, starter motor, and so on--were original and in excellent condition. The engine still had value, and I was able to sell it for a very good price, which was important to offset the cost of a replacement engine.
In a nostalgic frame of mind, I can say I miss the old engine. There was some pleasure to be taken from keeping an older mechanical device going, keeping it running in like-new performance and condition. But I am very happy with the modern engine that replaced it. I don't want to go back.
posted 06-15-2015 01:59 PM ET (US)
On my 1995 Outrage 21 (took delivery October 1994), I had a Yamaha F200 TXRT, two-stroke. Really, it was an incredible experience. I had it until my re-power a little over a year ago so in essence, 20 years.
After maybe 5 years, if I ran the boat for maybe 2 hours or more, and then [turned] it off, the engine would flood--guaranteed. The dealer tried and failed to fix the problem three times. That is when I found Gonzalo, now at West Coast Marine in Costa Mesa, California. He fixed the [flooding problem] and did my annual service. He is Five-star-gold and did all my annual services for the next 15 years. That was key to my success. Another point is that every drop of oil was Yamalube for the full 20 years. I changed the water pump on a regular basis. At 18 years, I needed a new starter. At 19 years, something happened where the propeller only engaged in reverse, and, if forward, it was just a grinding noise. That's when I did the re-power. The drawbacks of the two-stroke were smoke and smell. New two strokes [don't have smoke or smell]. Having to put in engine oil was [a concern]. Yamalube is more expensive and not found everywhere. The fuel dock wanted $65-per-jug. Gonzalo had $20 to $25 jug refills. Just a pain. The mileage stunk, but, again, not quite the [problem] with today's two-stroke engines. I am amazed how trouble-free my experience was. At the end, I feel I was getting into that mode where repairs would get costly and unpredictable breakdowns would be more common. I'm an ocean guy traveling far distances. I have Vessel Assist Gold but I don't want to use it. So it was time.
posted 06-16-2015 06:56 AM ET (US)
Biggest problem with carburetors on a boat or car these days is finding a good carburetor mechanic and good parts that survive ethanol.
Modern engines are built for ethanol, but you still have to find a good mechanic to work on the new stuff. Carburetors changed very little over time, but the new computerized stuff changes frequently so as [an outboard engines] ages, you will have problems getting parts if you have anything with low production numbers. Original equipment parts will disappear and there will be little or no aftermarket to supply those parts.
Like everything else today, these new outboards may become throwaways. You may not get 20 years of trouble free service.
But the new stuff does really work great and we have little choice other than to buy it when the time comes to replace an outboard.
posted 06-16-2015 01:01 PM ET (US)
The Yamaha in discussion is closing in on 400 hours this season. In fact the whole rig is the same so for 1999 I feel content to leave it for now. Although it's old it may be wise just to use it, take care of it and appreciate the vintage that works still. My biggest complaints are the smell and the gas mileage at low speeds. I don't think it really cares it just wants to keep sucking back no matter what engine speed, although in all fairness is decent at cruise. It lets out a little puff of bluish white smoke at first cold start then clears up right away and is great all day. The smell is annoying! I feel bad for the kids but we never complained. When growing up [the smell] was far worse, I seem to remember. This engine is noticeable quieter them my previous 2007 Optimax V6 DFI and is older technology. The new F200 can get past 4-MPG at cruise on same boat, so, other than the ticket price, seems attractive option up there with the ETEC if going that route.
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