I'm thinking of getting a 4 stroke but one of the guys at the field said not to. He says more to go wrong with them and if you damage it it would cost the same to replace it over trying to fix it. Also, he said 4 strokes are not for beginners! I'm not a beginner, just don't have 20 years under my belt. Then they are too complicated and will just cause me trouble. He swears by 2 strokes. Are 4 strokes that complicated? But almost all the old guys have 4 strokes. Why can't a young flyer use one? I'm not young (28) just young to them. Why do they keep trying to stear me away from a 4 stroke.

I don't know, they do have higher maintenance, but not a great deal more. Two strokes have more power. I use two strokes mostly. Four strokes are good for scale, because they sound more like the real thing. Though sometimes a slow reving two stroke sounds good too.

I kind of thought the same way for a long time... Then I got my first 4 stroke and have never looked back.. Perhaps a little more intitial maintanence but once broken in and running I seldom touch the settings on mine... As for power IMHO I think they are getting pretty close... The two strokes put out more rpm and the 4 strokes put out more torque... Then there is the sound of a 4 stroke... Adds a whole nother dimension to flying....

My guess is that "old time" pilots are either trying to save you some money or grief or both. They probably had a bad expierence with thier first 4S and they are just trying to pass that experience on to you. However, IMO, 4S really aren't that difficult to setup.

4S by thier very nature are more complicated than 2S... but too complicated? Maybe for a beginner, as they already have enough stuff to learn. But if you can properly tune a 2S, you shouldn't have too many problems learning to tune/maintain a 4S.

2S are about as simple as an engine can get. But, on most 4S, the only extra adjustment is rocker clearance. On a high performance 4S, like a YS, you will also have a regulator to fiddle with. Without a doubt, this is more complicated that a 2S, but it is not overwhelming IMO. I typically check rockers after about 5 hours run time and once all needles/regulators are set, they typically don't need to be readjusted much if at all.

4S typically are more expensive compared to an = powered 2S, and they have more parts, so they are typically more expensive to fix. But the solution is simple... Just don't break it. Be sure the run the proper oil in the right % and don't lean run and you will be fine.

Try a four stroke, and have some fun. A good one to start out on is the Magnum
.91. You can put them in any 60 size plane and have a ball. They are the simplest
and easiest to tune....all the parts are available, and they go on sale at Hobby
People about every other month.

FBD.

4-strokes also take a much longer time to break-in, being ringed engines, as opposed to ABC. ABC engines, you can run a couple of tanks through them in a rich 2-cycle and they are good to fly. 4-stroke ringed engines need a good bit of slobbering rich running, then rich running in the air. I typically run 1/2 gallon of fuel with extra castor in smaller engines (.72 & less) and a gallon in larger 4-strokes on my bench, then fly. A Saito will take 2 gallons plus to be really running great. My Magnums seem to take the same time or maybe slightly less to break-in.

There are advantages to both and disadvantages. I like my screaming 2-strokes, but there is something nice about a deep throated 4 banger turning a big prop.

Prejudice.

Attitudes vary depending upon the individual club, and seldom do they coincide with logic. Dogmatic opinions on the 4 vs 2 stroke argument are ego driven and emotively based in the same vein as the mode 1 vs mode 2 debates. There are however predominently logical pros and cons you can use to determine whether a 4 or 2 stroke is best for any proposed scenario, though in the end, the decision seldom comes down to anything other than pure desire and a novelty or prejudicial driven preference.

I don't buy the "4 strokes sound more realistic" rationalisation. They sound like a single cylinder model engine period.

In the end, more than anything at this time it still really comes down to your budget, but the theoretical pros and cons are:

Four stroke
Cons
Much more expensive
Relatively fragile
Less powerful per capacity
Much poorer power to weight ratio

Pros
Lower fuel consumption
Can usually be propped quieter (diameter and RPM related)
Torquier per rated power output (not per capacity)

Differences - neither pros nor cons
slower reving
different exhaust note
novelty appeal
exclusivity &/or status appeal eg: YS


Two stroke
Cons
Higher fuel consumption
Noisier when propped for very high rpm or inadequately silenced
Peakier power curve

Pros
Inexpensive
Wider selection
Robust
Powerful for capacity
Excellent power to weight ratio
Fast

Differences - neither pros nor cons
faster reving
different exhaust note
also ran appeal & status

Bottom line is if you want one, get one and try it. You might like it. Ultimately which you choose should ideally comes down to what brings you most enjoyment, what you can afford and which is best suited to the role you have in mind for it.

While I disagree with a few of the PROS/CONS I think it also depends on what your putting it on. Some applications are better suited one way or the other. On the whole people who are anti four stroke havn't owned one in the last 10 years.
What plane are you wanting an engine for?

David

I have both, most of my 2 strokes are converted to diesel since I fly sport and scale both the 2 strk diesels and the 4 strks are
propped to turn approx 8000 to about 9500 which make them pretty quiet I have had no problems with the 4 strokes, and they
run as reliable as my diesels 30 thru 1,2 on the 4 strokes and thru 90 on the 2 strokes < My latest 4 strk a neat little enya 40 open
rocker I like the sound will have to find a plane for it martin

Nice list Sigrun.

Agree wholeheartedly - if one has the surplus income for budget not to be an issue in the case of preferring a 4 stroke. Most applications can be addressed by either type without undue compromise if personal preference and prejudice is laid aside. Bottom line is that two-strokes as a general rule undeniably offer more bang for the buck.

I think that''s rather an overgeneralisation about as accurate as saying that the anti two-stroke brigade are all are elitist snobs. ;P

Suck and blow - who needs intake - pause - compression - pause - power - pause - and exhaust - pause - do we really need all that extra scrap metal clanking in unison to achieve half the power in twice the time?

Ehehehehehe..........now you're making me cry Dan. Waaaaaa. Oh ...for some diesel fuel!

An Extreme Flight Edge 540.

Definately 4 stroke material! An EF edge is perfect for a 4 stroke. After getting my first YS 4 stroke I havent looked back! The only thing they are not suited for is quickie 500's or any other plane you want to go real real fast. Otherwise If you have a few extra $$$ try it!
Now for the new debate..... which 4 stroke????

4 strokes all the way... Obviously some people have not tried/heard of YS, Laser etc when it comes to power... I also run 4 strokes in my car. Some of the stongest engines around..

You don't need 20 years under your belt to tune a four stroke. In fact, younger guys tend to be better at tuning a four stroke than an old geezer. A four stroke has a low end adjustment screw and a high speed needle valve just like a two stroke. YS four stroke has an extra adjustment screw to tune the midrange, but that's about it. Tuning a four stroke is like taking a walk in the park.

Yeah, thinking OS 70.

Damn, still can't decide on 2 or 4. OS 70, MVVS .49, OS 50SX,, the list goes on........

My second engine was a 4-stroke, an O.S. 91 Surpass. They are no harder to tune than a 2-stroke, like Richard L. said they have the same adjustments. I use 4-strokes on everything, except my giant scale (2-stroke gassers). I doubt I will ever buy another 2-stroke. The argument about 2-strokes being lighter and more powerful doesn't hold that much weight anymore. My Saito 82a 4-stroke is as light as any .46 2-stroke and swings a 14" prop at 9000 rpm. That's light weight with lots of power! If you want speed take a look at the YS. Richard L. runs YS 63's in his warbirds and will attest to their performance. In my opinion, for an aerobat such as your Edge, a 4-stroke is the best choice. Good luck!

I have the OS 120 4S with pump and it has ran great for over a year now. I see OS has a 70 with pump also which should be a good engine. Having had both 2 and 4 stroke engines I enjoy the sound 4S puts out and feel it is worth the investment.

sigrun, go price a Jett 60 and a YS 63.

Snob appeal has nothing to do with anything.

I would say that maybe 80% of the people at my field wouldn't know that Jett was more expensive than the YS. So yes snob appeal does have something to do with it. That said the Jett's are not as good with low speed torque as some other engines. A Fox .60 or .74 would out pull the YS .63 at rest, not sure the Jett would do the same.

- body txt deleted by sigrun -

4 Stroke all the way on that plane. You won't be sorry.

David

quote:

ORIGINAL: ChuckAuger

sigrun, go price a Jett 60 and a YS 63.

Snob appeal has nothing to do with anything. [/quote]


I don''t know whether you're dyslexic or simply not very bright? But if you really think "snob appeal has nothing to do with anything", it leaves little doubt that it's the latter. Suggest you read what I wrote again, and this time make an effort to comprehend it before the testosterone kicks in.

Well, not dyslexic. Maybe not too bright.

But bright enough to read this:

And I would also not agree with this:

And in case I missed something, I offer up this bit:

So it's not snob appeal?? Oh, just a misunderstanding!

BSE .61L R/C with muffler** AAC
15,000
11x6
16.8
$315.00


See, there are high end sport 2 stokes. I don't think people who own them are snobs. I'd take a while longer to dissect your comments, but I get the gist...If I run 4 Strokes, eg YS, I am an elitist snob. Cool.[8D]

go for it.