I apologize if this is an elementary question but I am a new homeowner and do not have alot of knowledge on engines in general.

I have a 1/4 acre lot and plan to do my own lawn maintenance. I've already purchased my mower and am now looking at getting a trimmer.

I've noticied the big difference in gas-powered trimmers seems to be 2-cycle or a 4-cycle engine but I'm not clear what the pros and cons are of each. Also in some of my research I see that some units take straight gas whereas others require a mixture. I'm just completely confused at this point at what to even start looking for. I dont have a large lot that requires a tremendous amount of trimming but I want to purchase a unit that will be durable and most fit my needs. Maybe my needs would be better suited with an electric model?

Any explanations and advice would be greatly appreciated.

hey looky there, a fellow rochestarian.  Cold today, eh? :)

to answer your ? quick and simple:

2cycle(or 2 stroke) engines are the engines that  you mix the gas an oil together.  As the mix gets burned in the engine, the oil in it lubes the engine
4cycle(or 4 stroke) engines are like those in your car(in fact your car is a 4 stroke motor) they have a crankcase and an oil distribution system.  The oil and gas are not mixed.  They use "straight gas"

What's better? well, that debate could rage forever.  Suffice it to say that because they are cleaner, the 4 strokers are gaining more and more popularity, in fact i seem to recall there being some EPA law that says all ope engines will have to be 4 stroke by like 2010-someone correct me if im wrong.  Day was you could pack alot more power in alot smaller space and alot lighter package with a 2 stroke engine, but that isn't always the case.

One nice thing about having 4 stroke equipment is that you only need one gas can :)  I have a gas can for my tiller, trimmer, blower and chainsaw.  Plus two cans for my  4 stroke stuff.

Welcome to the forum.

Four cycle engines use gasoling that does not require mixing with oil, two cycle engines require it.

For the most part, 2 cycle engines are lighter thus making the trimmer easier to carry around. In trimmers, 2 cycle engines from the major companies like Echo and Stihl for example, have inexpensive maintenance parts and they generally easily found. The 4 cycle engines like the Honda, are going to be more expensive in that manner. If it is indeed Honda you are looking at, they are more expensive anyway. 2 cycle engines are oiled by the oil that is mixed in with the gasoline and have no problems with oiling regardless of what position the engine is used in. This could potentially be a problem with 4 cycles but I believe with the way Honda designed their engines this is really a non issue. I guess I could talk about RPM's but there is really no need to do so.

I prefer a strait shaft trimmer, regardless of brand. I find them easier on my back, easier to reach under overhangs and easier to control in general. You might look at Echo's SRM-210 .


Others may have more differences than I put down here but, to me, these are the ones that make the biggest difference to a user.

terrapin24h wrote:

Hi Terrapin,

I may be wrong as well, but I seem to recall that the EPA does not mandate the type of engines that must be used now or in the future, rather they only care about the emissions being reduced on all engines including 2-stroke OPE.  I'll look into this to be sure and get back to you.

Thanks for the reply!

Yeah, those wind gusts today are making it downright frigid today. I think the fact that  I have lawn care on the brain is my subconscience saying "cant wait for spring to get here!" :)

I think the convience of having one gas can for both my mower and trimmer is the best reason for me to go with a 4-stroke engine. After doing some google searches I can see that the topic can be quite debatable so I didnt want to start any arguments either way but wanted to determine what was best given my situation.

My next door neighbor has a ryobi 4 stroke and he likes it- but he rarely uses it :)  I have an el cheapo weedeater brand featherlite plus that i bought specifically for its weight.  I can sling that lil bugger around like a fly swatter(i literally use it one handed alot).  The important thing, 2 stroke or 4 is that you get a machine that fits you right, and that you adjust the handles correctly.

One of the biggest advantages on the small 2 stroke engines is they do not have valves (valves on small air cooled engines wear fast or burn out much more readily )  ( to be specificn no mechanical valves)  They have ports, same as saying slide valves etc. No need to go into the actual operation.  The reason it is an advantage is small engines in the ope equip are high revving engines, the two cycle is better suited for high revs as it fires every time the piston comes to top dead center.  (the piston fires every rotation of the engine, not every other rotation as in a 4 cycle) that is important in a small engine doing this type job as for example a string trimmer.  These engines create a lot of heat running fast so that is why a 4 cycle engiine with mechanical valves would be detramental,  because with high heat the first thing to go is the valves.  Less parts on a two cycle, easier to repair,  you can call them self lubed if you want to, because whatever angle you put them at,  as long as it will run , most carbs won't run upside down, some do however,  great for airplanes  just kidding.whatever angle you put them at as long as they are running and you have oil in your fuel, then they assuridly are oiling themselves,  it is a fool-proof system, why, because if they are not oiling themselves they will not run.  The traditional system brings the oil and fuel mixture thru the crankcase first before it enters the combustion chamber.  there are some slightly modern enhanced versions who bring it thru the crankcase and a small inlet into the combustion chamber also.  but the engine will not run on that alone. 

 Not having valves that will burn out when run hot is an advantage.. Sure some one  will prob say they now heat treat the mechanical valves, which helps but they still burn Combustion heat on both sides of an exhaust valve which starts them splitting at the thin tips, it is hard to protect against that in these small engines.  Which is the reason that for generations they were nothing but 2 cycle.  And of course 2 cycle's have never burned out a valve.  LOL  it's true

If you want to chance adjusting or replacing valves in the future, then buy the 4 cycle.  they are nice engines and up to modern day tasks.  Just more potential kinks in their armor.. not to mention they can be heavier , more expensive, and you have to chg oil. they are a bit more quiet and have less vibration. But for the amount of time you use them,  even on a complicated property, the 2 cycle that will not burn valves is much better on your pocketbook  .  You spent 200 to 400 on a string trimmer, you sholdy consider how often you want to spend that, or put up with a little noise for awhile etc. (old saying "every thrill has it's chill"

Ben07

Ben07 wrote:
Ben07,
I don't disagree with everything you wrote in the above quote, I just take at least some exception to most of it.

Seezar,
In general, in my opinion, small trimmer and chain saw engines have changed so much in the last two years due to emissions, unless you are a pro user or fixer it is very hard to keep up. If you want to go inexpensive, go to a box, find one you like, check the return policy (make sure it is open ended for date), keep box and reciepts (everything that keeps the return policy in effect) and use it to your hearts content. Don't like it for any reason, take it back.

Once you find yourself spending $100 or so to get one you like, Bite the bullet  and maybe check into some good machines at a dealer. Echo, Redmax, Stihl, lots of other brands to consider, some well know like Honda, some not, like Shindaiwa.

Unless you have a preference, like not wanting to mix oil in the gas, I don't think I would worry about the two stroke-four stroke thing too much.

By the way, Welcome. And I am not a pro anything, please take my opinions for what they are worth.

robmints wrote:

Sorry Rob  but when I read his question I thought he specifically wanted to know what the pro's and cons were of a 2 cycle engine vs a 4 cycle  engine, Actually it is the title. I think every response has been on their differences, He even stated that he has looked at them and has come to the main differences are wether they are 2 cycle or 4 cycle, and that is specifically what he seemed to want to understand.   Apparently you only have a problem with my post ???   Actually most of mine. At least that is what you said, specifically what, I am not sure.    Maybe somethings wrong and I should erase the post.  I did give credit to both types, however far little to the four cycle in this small size market.  Now If I was going to give an opinion as you did, for which I might add he asked for explanations and opinions,  I gave him an explanation, and you gave him an opinion,  and you stated your opinion was based on my explanation.  Saying don't worry about the explanation you asked for, just go out and buy, then keep exchanging etc.    So I will  first give you my opinion on small 4 cycle engines of this size for ope use.  They are going to have to go a long and expensive way on 4 cycle tecxhnology in small engines like for string trimmers, to even come close to how the two cycle can handle it today. It may be able to be done some day, but the the consumer will pay a lot more.  .  The 4 cycle in this size is a mere toy compared to it's counterpart.  Also where we disagree is to have someone ask for an explanation, and tell them to go to the store and poke and hope till they find one  by trial and error and countless hours at the service desk.  when that is why they may have asked the question in the first place so as to not to have to do that, as much.  And this type practice makes the cost of goods and services higher for everyone in the long run.   Apparently they wanted to gain some knowledge before going out shopping again.

keep this in mind and let me quote you "I don't disagree with everything you wrote in the above quote, I just take at least some exception to most of it."     and at least I had the courtesy to explain why

Ben07

My professional opinion..............( I run one about 5 hours a day in the summer)  2 stroke all the way.  Nothing but Shindaiwa for me.  Smooth, powerful, built to last, light weight.

4 stroke.............BOAT ANCHOR HEAVY, ROUGH RUNNING, LOW POWER, VIBRATION (did I already say that ) BUT..........Very smooth idle...........if that is good for anything.

I tried out a Honda, Shindaiwa and Stihl...................didn't like any of them.

The Honda dealer was begging me to try one out.  I used it for about 20 min. and was NOT  impressed.  The others were tried for less time, but my review stands.

But hey....................that's just me.

Ken

PS-------I ONLY run Opti-2 for mix.  At the mix ratio I seriously doubt I am polluting any more than a 4 stoke engine.

Oh yeah............................WELCOME to the club, Seezar!  

Ken

Thanks everyone for the welcomes and the helpful info!

After reading all these replies I can see I'm not yet any closer to picking out the exact trimmer for me, but I've gained some knowledge.  That was my intent in the original post was to understand the difference in the 2 types of engines, it just happened that the reason I wanted to understand was I'm in the market to get a trimmer.

I think its going to come down to just going out and looking at a few different models, and as what was mentioned, try some out and use the return policy if needed. The last time I used a trimmer was about 15-20 years ago so I'm sure things have changed quite a bit since then.

Thanks again everyone, this is a great forum and I'm glad I've stumbled upon it.

Seezar  by the way it might be a worthwhile idea to start out with an inexpensive electric one. Then you can get the feel for what you prefer.  They serve as an excellent back-up, as in storage they don't have some of the problems you will have as with storing a gasoline one.  (carb gumming from some gas left in it, the magnet surfaces getting rusted there-by not enabling the sensor to pick up the point to fire the engine etc etc.)   I gave an old electric one to a new neighbor a couple years ago, it was about 25 yrs old, wasn't used in like 20 years, I stored in the worst way, a plastic bag.  Ran like it was new and he has been using it now for two years.

Ben07

I'm with you Ken, I'm a 2 stroke man all the way when it comes to trimmers and blowers, for the same reasons you mentioned. I do like 4 stroke thumpers though, in bikes!

Ben07,
Sorry I was so abrupt. No excuse, but I was in a hurry.

I am not an expert. I think I have owned over a thousand horsepower of two stroke machines in the last 20 years or so. I really like two strokes as a design.
Maybe I haven't been looking as close as I should have been, but in that 20 years I have only seen one two stroke engine that did not have some sort of valve, mostly reed valves.
I think the two stroke we used to think of, for the new purchaser, is gone. Most of the small, newer design two strokes look to have significant design changes to meet emissions standards. Many seem to have what we might consider a four stroke style valve, with a stem and seat. Some look like they differ on how they are actuated, but they do what they do on four stroke. Some engines seem to try to get away with what we used to call "loop charging" where the exhaust is reported to or held in the cylinder. Some seem to use a little "CVCC" thing that opens wth vacuum or pressure and closes with a spring. Others seem to use a cam and spring just like four stroke. But, for the most part, our beloved two stroke is dead. Onward and upward in the fantasy land of the EPA.

One thing with gas trimmers more than one person has indicated that they did not like was something called a split crank. I think they say you can tell by the recoil start being between the engine and the shaft. I have no idea what they are talking about. Hopefully someone that does will have some input.

Like you posted, Ben, electric might be something seezar might really want to consider.  Again, sorry, did not mean to seem like a jerk. Wasn't intentional.

hey guys...

ive been reading this since it started,and have a few things to comment on.

first is 4 strokes...in my professional opinion and im the pro here...they are all crap even the honda or maybe especially the honda cause they know better.

and the shindiawa,which is normally top quality equipment well we sell them and there is 5 pages of service bullitens that have to be done to them...thats crap to me.

as far as power the 2 stroke rules and the 4 stroke isnt going there any yime soon.

now that being said there are some real crappy 2 stroke trimmers out there.best way to tell if its any good is to take a look at where the starter recoil is.

if the starter handle is on the shaft or boom side then its a low buck special...exactly 1/2 crank in there,and also usually made of pressed and pinned sheetmetal.the crank is only supported on one side of the connecting rod.

if the starter is on the top side  away from the shaft then it is a full crank and usually has a real crankshaft 

and it is supported on bothsides of the connecting rod . 

dosent matter what kind of brand it is the one with the good crank is always better than the one without.

i have never seen a poor machine that had the full crank ,they all have good quality product and some of them have not so good product as well.

read what folks have to say here and be advised.

as far as the 2 strokes being non emission friendly,well just do your part use a good quality synthetic mix oil and dont let it go stale.

later chris  

Canada

USA



Chris, As you know many of our true two strokes are NLA here. We get more and more stuff like Stihl 4 mix engines. For instance we can't get a FS85 here. If it's not one thing, It's an udder.

I never noticed this before but it's pretty strong selling foo foo dust.


http://www.echo-usa.com/300.asp

300 Hour Certification

INDUSTRY FIRSTS | CATALOGS | MANUALS | FAQs |

With a premium brand like Echo, you expect professional-grade performance. And no engines in the industry perform like Echo. Every engine Echo produces is certified with CARB and EPA to its highest useful life* rating – 300 hours. And that’s the highest performance rating there is. Some manufacturers claim professional-grade performance and yet rate their engines at only 50 hours. Be sure to check the label and you’ll find every Echo product will have a 300 hour or “A” category rating. It’s a fact: Echo delivers the highest level of useful life in every product. * EDP is defined by CARB as “Emissions Durability Period”. EPA uses the term “useful life”, which is defined as “…when engine performance deteriorates to the point where usefulness and/or reliability is impacted to a degree sufficient to necessitate overhaul or replacement…” (U.S. Government, Code of Federal Regulations, Vol. 40, Chapter 1, Sec. 90.105, par. 5, §ii)

Rob thanks for the post,  and I am in a little hurry here, so I could come off wrong.    Now I am not kidding when I said thank you.  But I have a disagreement with you saying modern 2 cycle engines have mechanical valves, and we are talking in the internal combustion area, as my original point is they are prone to burn out there on small ope engines, like string trimmers etc. 

The engine you posted and used as an example is not a two cycle engine. It is a hybrid.   It isn't even close to a 2 cycle. it uses a 4 stroke cycle which needs mechanical valves in the combustion area..

Stihl is one of the new kids on the block with it, so I will post their info admitting it is a 4 stroke.

I have never seen any 2 cycle engine with any internal mechanical valve in the combustion area. (maybe that don't mean there are none so feel free to show me, I'm here to learn)) .  The reed valve is a trap door check valve, sometimes called a flapper valve , flow direction valve, whatever. It is normally between the carburetor and the crankcase of the engine,  In short no where near the internal combustion area.  on some two cycles it is actually incorporated in the carborator.  Certainly wouldn't want any combustion or excessive heat in there. 

The engine you are describing and posting a picture of is called a Hybrid 4 mix.  It is not a 2 cycle engine.  It is a 4 cycle engine with oil mixed in with it's gas, as they are trying to duplicate the lubrication system (and only the lubrication system)  of a reliable 2 cycle, because 2 cycles are able to run upside down and still lube themselves. I will see if I can past  in Stihl's  drawings and explanation of it.  They clearly state it is a 4 cycle engine.  That's why it has valves in the internal combustion area.  What the crazy EPA is  having these guys try  to invent  is a  substitute for the mighty and maintenance free 2 cycle, and they have went as far as throwing oil in the gasoline of a 4 cycle "Otto" engine. I only mentioned the inventor cause I wanted to say he gotta be rollin around in his grave over this. 

     All kidding aside,  I like those young engineers experimenting,  because someday they may come up with something better..It is possible.   But if they do it ain't going to be in fine print at the bottom of an advertisement.  It will be on the front page of Fortune Magazine,  and naturally it will also be so complicated and un-affordable the whole article will be, them telling us how not to worry cause we really won't have to pay for it.  etc etc. 

Here's Stihl's explanation   http://www.popsci.com/popsci/bown/2003/article/0,18881,537079,00.html

Illustration by Garry Marshall

Two-stroke engines (1) have two main benefits: They have a high power-to-weight ratio, and they can be run upside down. Yet these perks come at a price: The two-stroke configuration is valveless, and some of its unburnt fuel leaks out as exhaust. Four-stroke engines (2), though not as powerful, have a valve on the exhaust, so they are cleaner. The crankshaft is lubricated with oil in a pan, however, so they cannot be turned upside down. A two-stroke gets around this by using an oil-gas mixture for both fuel and lubrication. (3) The Stihl 4-Mix Engine takes the best parts of both engines. It uses a four-stroke cycle, so exhaust valves prevent the escape of unburnt fuel, yet its gas-oil mixture lubricates the crankshaft the way a two-stroke does, so the engine can be oriented in any direction. As the crankshaft turns, it sucks lubricating fuel into the crankcase. This keeps the entire crankshaft lubricated even when the engine is upside down.   The real problem I have with their advertisment, is how can they claim they can ever hope to get more power in the same size 4-cycle.  When all they are doing is altering the lubrication system,  (sry but getting rid of a conventional splash system just won't even come close)  My guess would be some of the same horsepower lies we have investigated in other threads, as in using horsepower in and over operating range  etc.  Who knows maybe they are talking at idle speed.  It could be true there.  What good it will do there is beyond me.   Anyhow call it up, some interesting pictures of the different styles of engines. And remember their claim of more power in the same size engine is in fine print at the bottom of the article..Sure ain't the new york times. Ben07

 

snowshoveler wrote:

Hey Chris..........................

Please don't think I'm trying to steal any thunder from you, here.   I do bow to you the professional technican!  I have a landscape maintenance company that has been in business since 1988.  I am definately an end user and not a tech., but with countless hours of use "under my belt", I know what works and what doesn't.  I've tried them all.  I can only extend the knowledge that if something stands up to commercial use, then it will likely be a lifetime purchase to homeowner use.  And, that, is money saved in the long run. 

I think that one of the greatest things about this site is the fact that all the knowledge shared results in wiser spending of our hard earned dollars by "crying once" and buying better quality OPE. 

Ken

I think I really only had two points from the beginning.

Two stroke engines have changed a lot in the last couple of years from what most of us are used to, in order to comply to EPA standards here in the US.

Even old time two stroke engines have valves, called reed valves that can fail and cause the machine to run poorly or not at all. And they do fail from time to time.

robmints wrote:

I remember my dad saying that the reed valves would get weak from "flapping" all the time and would usually be the cause of poorly running machines (usually Lawnboys) that would come into the shop.  I've worn out a few myself from back in the day when we ran Lawnboys exclusively.

Ken

Great in-action working model of a 2 cycle
http://www.oldengineshed.com/twocycthry.html

well folks the still 4mix is a carbon copy of shindiawas 4 stroke unit and neither one is much good.we sold the shindiawa 4 stroke units and after i get done doing all the recalls and updates ill be an old man.

i really hate it when a company brings out somthing and claims its te best thing since sliced bread,then we find out it went mouldy and has to come back in for repairs .

eventually they will bring in fuel injection and that will be the end of 4 strokes.

now i know some of you are saying no way but what if i tell you that your precious 4 stroke isnt so clean after all and the only reason they build them at all is so they can earn credits to play off on their not so clean units.

did you know that fuel injected  2 strokes have been tested to run at a mix equal to 400 to 1. they are variable ratio oil injected ...changes with load and rpm.

its complicated now but getting better all the time.

a fuel injection 2 stroke can run cleaner than almost every 4 stroke.

dont beleive me check out a mercury outboard called OPTIMAX...awsome engineering in that thing and cleaner than any other 4 stroke outboard.

i like 4 strokes but they have not earned their place in small hand held ope yet.

later chris

Chris,
What about Echo's Tornado power, or what ever they call it.

echo is top quality product (used to sell it) but you could look at a srm 2300 or 2500 and have a very nice machine  that will last a lifetime with little or no maintenence.

i feel that the 4 stroke are gonna be a problem after a couple of years ,especially if they dont get used much.

just check out the price of a carb kit for any 4 stroke trimmer and maybe a spark plug ...if you can find one ,and you wont fine one at walmart.

if you leave you gas get stale once its gonna be very costly,i end up replacing every second carb on the 4strokes if you even mention bad gas around one of them.

and that just makes them impractical to me.

stale gas is a way of life we all do it from time to time and  sure its anoying ,but with these ones your gonna pay through the nose

.buttlint ...how much does a carb lit cost for one of your stihl 4 strokes and how many do you have in stock...the kit i mean not the trimmer.

later chris

Well, SnowShoveler has pretty much convinced me to go with a 2 cycle trimmer.

I had been considering the Honda units, but had some concerns.  I am leaning towards the Echo 230 or possibly the PAS-260 for some flexibility with trimmer, edger attachments.  Though some say that the you should't use the PAS model for your primary edger.  I guess my question is - if you should not use it as your primary edger, what is the point?   Are you better off with a dedicated edger?

Also, liked a Husky model I saw - 326.

Not as primary edger? Bullsnot.

Mine works fine, has for years. Bottom line is, once you have a nice groove, it doesn't take much at all, you'll fly down it.

Marshall wrote:

Absolutely correct!  If you keep it up, it is a breeze to do.  You do not need a dedicated machine that will sit most of the time.

Ken

Terp wrote:

I have to say that after having the Honda dealer practically begging me to try one out, I was really expecting something.  What a let down!   I was not impressed with the handling at all, and I think Snowshoveler sums it up about this move to 4 stroke technology.  Also, I don't know of ANYONE, either in person, or on the net that uses a Honda trimmer commercially.

I havn't had a chance to run one of the Husky 326's yet, but I have handled them and checked them out quite closely and they seem to be well made.  It is light but strong where it needs it.  I know of some other maintenance guys that have them and I havn't heard any complaints.

Ken

hey guys the husky 326 is a very nice machine and if you want the edger ,just buy the split boom unit and then get any extra tools you want.

we sold the earlier version 325 as fast as we could get them...around 30 or 40 a year and thats a lot in a small shop like ours.

have next to no trouble with them...they have the green gas cap i beleive which means they have a cat in the exhaust ,makes them a bit cleaner .

they always start well and have lotsa power.

i dont usually bragg up the stuff we sell cause it seems like im pushing product and thats not right .but if you ask i will fess up.

later chris

snowshoveler wrote:

Chris,

You should check out Evinrudes new E-TEC direct injection 2-stroke engine.  The R&D that went into it is just amazing.  The technology is here, it's just a matter of the consumer needing to scream for it, or the EPA to really come down hard on the OPE industry to mandate it.    I'd love to see technology like that for snowblowers. 

Richie wrote:
I know this is not 2 vs 4 cycle but you got into Outboards and it took me here. LOL 

Check it out, wouldn't your 24" runabout just haul ass with one of these..........

Mercury HP1075 SCi

HP: 1075
kW: 790
Full Throttle RPM Range: 5600-6000
Displacement Liter/CID: 9.1/557
Bore & Stroke (in): 4.50 x 4.375
Bore & Stroke (mm): 114 x 111
Compression Ratio: 8.00:1
Cylinders: V-8
Alternator Amp: 65
Alternator Watt: 917
Ignition System: PCM 03 Distributorless
Fuel System: Sequential Fuel Injection
Fuel Requirements: 91 Posted Octane (R+M)/2 (98 RON) International
Transmission: Huber 1450 Series
Drive Unit: Dry-Sump Six Drive
Gear Ratio: 1.15:1, 1.24:1, 1.35:1, 1.42:1, 1.50:1 or 1.61:1 (right- or left-hand)
Length (in/mm): 55/1397
Width (in/mm): 40/1016 (w/CMI Exhaust System)
Height (in/mm): 30/762
Weight (lbs / kg): 1720/782
Warranty: 90-day limited for recreational boating

HP1075 SCi

Mercury Racing is pleased to announce the release of the HP1075 SCi sterndrive - the world’s most advanced big block performance sterndrive and latest innovation to come from the world leaders in advanced marine propulsion systems.

The Mercury exclusive Propulsion Control Module (PCM) 03 microprocessor is the brain behind the brawn, giving this monster motor a friendly personality. Based on a high performance 557-cubic inch V-8 cylinder block, the 1075 SCi features a pair of Lysholm twin screw super chargers with multiport fuel injection (two injectors per cylinder). This combination provides sport boaters with turn-key starting, great overall running quality and incredibly smooth idle quality for a high horsepower big block. The engine’s 800 RPM idle speed makes shifting into and out of gear smooth as silk, making docking much easier with less chance of stalling and other low-RPM drawbacks normally associated with big horsepower.

Mercury Racing, along with its parent company Mercury Marine, is the first marine engine manufacturer to be ISO 9001:2000 certified. The ISO certification is a reflection of Mercury Racing’s high standards and dedication to continue its leadership position in the marine industry. No other high performance marine engine manufacturer puts more time and attention to detail into product development. All products undergo numerous hours of grueling validation tests before they receive the Mercury Racing name.

The 1075 SCi is the first engine to be accredited by Mercury Racing’s TEAM (Total Engine Application Management) initiative. The standardized TEAM process ensures proper installation of the engine with factory-specified components, providing maximum performance along with unmatched quality and durability. The 1075 SCi will only be sold to accredited OEM boat builders and dealers.

Mercury Racing engineers designed the 1075 SCi for ease of installation. Every component is strategically placed with an end package that is as compact as possible. The twin screw compressors, which require less power than traditional roots blowers, sit on a corrosion resistant charge air cooler and induction system designed exclusively by Mercury Racing. Their low-profile design helps to reduce overall engine height and center of gravity. In fact, the 1075 SCi is eight inches shorter than the HP900 SC Dry-Sump, allowing boat builders to replace air scoops for sun pads.

Super charger induction noise levels are controlled by twin carbon fiber Helmholtz air inlet resonators. Twin flame arrestors act also as air filters, keeping the engine’s air induction system clean and efficient.

Super charger boost is variable. A boost bypass control valve, electronically activated by the PCM 03 microprocessor, continuously adjusts the amount of boost needed to provide consistent horsepower. Under optimum ambient conditions, the boost bypass control valve will open to adjust for the lower boost required to obtain 1075 horsepower. The PCM 03 controller closes the bypass control valve, to provide the additional boost required to maintain a consistent 1075 horsepower when operating in sub-optimal running conditions and limited higher altitude environments. The 1075 SCi’s ability to provide a consistent horsepower in any condition or locale eliminates the hassle of re-propping the boat to match conditions. The PCM 03 computer also enables individual cylinder control. This ability to optimize fuel, spark timing and knock control independently for each cylinder enhances engine running quality, performance, fuel economy, and durability. The use of eight independent ignition coils, one per cylinder, helps eliminate spark plug fouling.

The 1075 SCi comes equipped with the digital SmartCraft Controller Area Network (CAN) system, a network of sensors that proactively monitor engine functions. The next wave in boating, SmartCraft Integrated Marine Technology from Mercury links power, controls and internal and external sensors to provide precise data on all boat functions at a glance. The system monitors a variety of vital engine functions including fuel flow, fuel range, fuel used, and RPM, along with water depth, trim angle, water pressure and battery voltage. Boat functions monitored include fuel tank levels and water and waste tank levels. The CAN enables the PCM 03 to communicate data to optional SmartCraft SC5000 System View and System Link gauges for real-time data on multiple engine and boat functions.
The PCM 03 also drives the exclusive Engine Guardian™ System. Engine Guardian monitors engine functions to forewarn of possible problems that could lead to engine damage. This “smart” technology not only detects and alerts the boater of a problem; it processes the data and reduces power to a maximum, safe level that allows the boater to continue operation. Engine Guardian also has the ability to proactively help prevent engine overheating by sensing not only engine temperature but cooling water pressure as well. By sensing water pressure, and temperature, the system can provide advanced warning to the PCM 03 control module, which then reduces engine power before temperature related engine damage takes place.

Similar to the Mercury Racing Super Cat and Super V offshore race engines, the 1075 SCi features a dry-sump lubrication system. Three scavenge pumps and one pressure pump keep oil off the crankshaft, reducing friction for enhanced power and performance. A remote oil tank separates air from the oil and gives it time to settle, providing the pressure pump with a constant supply of oil. The oil tank also reduces foaming, improving overall oil lubrication, even in the most adverse sea conditions.

Custom sealing systems, developed by Mercury Racing, enhance engine durability. The use of corrosion-resistant engine components and treatments enhance engine quality and protection against the corrosive saltwater environment.
An all-new, thermostatically-controlled, high-velocity cooling system uses a combination of a circulating pump and sea pump to keep the engine at an optimal operating temperature and peak performance. The system utilizes a three-stage sea pump. Two stages feed cooling water to the engine block and cylinder heads while the third stage feeds the charger air cooler.

Longer valve train life is the result of Mercury Racing dynamic optimization utilizing in-house valve train dynamics test rig.

A high-output, 65-amp alternator provides increased power at idle and full power. The increased charging capacity makes running a variety of electronic accessories worry-free.

The 1075 SCi is built from the bare block to completion in Mercury Racing's four-cycle Race Shop. Technicians use specialized components throughout the engine, from the heavy-duty valve train to the custom fabricated steel oil pan. Engine packages come standard with the Mercury Racing dry-sump Six drive.

Mercury Racing

Marshall wrote:

Hi Marshall,

Exactly my point.  I was amazed at how efficient Evinrude's technology is, not to mention they actually raised the bar on 2-stokes.  I only wish our OPE 4-strokes engines could also be brought into 2005 as well.  I'd certainly expect to pay more for a machine, but you can't beat an efficient combustion chamber design.  I'd like to see carburetors disappear altogether and a more efficient piston and cylinder head design as well.   Ski-doo and Artic Cat snowmobiles have been very successful using two types of fuel injection on their 2-stokes, I'm sure it's a matter of time before the OPE industry catches up.  It will require a new engine design as soon as some of the newer emission standards start kicking in. 

thats exactly my point guys...

i used to be in the marine industry and was certified for OMC as well as mercury and mercruiser.

have you ever heard a 900sc mercruiser (predecessor to the one marshall posted)just sitting there idling.was the sweetest thing i ever heard...and i got to work on it.

which brings me to my point.

the 2 strokes can make lots of power and burn cleaner than a lot of 4 strokes ,the technology is  there .we are just waiting to have it .

later chris

Too bad Evinrude didn't compare their H.O. 225 E-Tec against Merc's OptiMax 225 Pro SX.

I know I have lost my mind. But after having 2 strokes from a 5 HP Wizard to a 200 Yamaha to now a 140 Johnson, if the Johnson ever wore out, I would look at this Honda. The only thing I like better about the 4 stroke outboards is they are quiet.

Rob,

I think the 4 stroke outboards also get a little better fuel consumption rate.

                                                                                                                        Fred   

Rob, those Honda's are darn nice engines for family pleasure boating! Great fuel economy, quiet and reliable.