I am in the process of putting together my 1st trainer (a [link=http://www.sigmfg.com/cgi-bin/dpsmart.exe/MainMenuFV4.html?E+Sig]SIG Kadet Senior[/link]). My question is this: I really like the sound of the 4-stroke engines but have heard differing views as to the added complexity, maintenance, etc. of the 4-stroke. One flight instructor I talked to said that its not that much different than the 2-stroke. Would you recommend sticking to a 2-stroke for my 1st engine? Also, any particular brand engine that I should avoid? I have been eyeballing the Magnum 4-strokes.

In my humble opioion, the biggest difference is price. I cannot speak for the Magnum 4 strokes, however I can speak for the OS and the Saito. Once they are set, they are no problem at all. I do use a different fuel on my 4 strokes than my 2 strokes and that is all about the ammount of lubrication in the fuel and I am not really sure that it is needed. Good Luck, Dave

I agree with Davidagar, there isn't much difference between a 4-stroke and a 2-stroke. If you want one go ahead and get it. The only thing I would recommend is to get a tachometer at the same time. The reason for this is that a 4-stroke takes longer for you to get the hang of tuning it by ear. On a 2-stroke the RPM changes are pretty easy to hear and pick up, but tuning a 4-stroke can be a little bit more subtle. The tach will help you to tune the engine until you get used to it. After awhile of using the tach you'll be able to pick up the changes easily.

I agree, there is nothing that sounds sweeter than a 4-stroke engine!!!

Ken

I've been running my first 4 stroke for about 3 months now... Magnum .91. From my personal experience, it is no more difficult to operate than any of the two strokes I have. In fact, I've had LESS trouble tuning the Magnum than I have had with my 2 strokes. Once it's set, that's pretty much the end of it. The only thing you need to pay closer attention to is the break in proceedure. I dont know about the others, but Magnum outlines this step by step in their manual. I run the same fuel in mine as I do in my 2 stokes (17% nitro, 18% oil). It will need an occasional valve adjustment, but that's easy to do. I would say if you want a 4 stroke, go for it. You wont have any trouble if you just follow the break in recommendations and feed it good fuel with a minimum of 18% oil.

Oh yes, as Ken said, get yourself a tach... it makes tuning much easier than by ear until you get the hang of the different sound. And what a sweet sound it is!

I'll be the contrarian and say there are are significant differences between 2 strokes and 4 strokes. Two strokes are louder, less fuel efficient, but are ever so slightly easier to maintain. Four strokes are quieter, require slightly more care with maintenance and setup, but are more fuel efficient. Are these differences a problem for a beginner? Absolutely not. So, while I'm being a contrarian, in reality, I agree with Ken and Dave . If you like the idea of a four stroke, go ahead and get one. I think it's a great choice for a plane like a Kadet Senior.

As Ken suggested, buy a tach, it will help you learn how to set the engine appropriately rich, and also help you ensure that you don't underprop it. As for buying Magnum four strokes, I see lots of people reporting positive experiences with them.

With a properly set engine, there is no difference between the engines.
If you have the engine run lean, the two stroke will continue to run but will overheat and over time will suffer significant damage. The four stroke will usually back fire and throw the spinner or propeller. Over time the 4 stroke will be damaged as well.

Ah heck, get the 4 banger. I bought seven of them before I bought my first two stroke. Get it, you'll love it.

I usually recommend a cheaper two stroke for a first engine, like a 46 LA for that plane, because sometimes the first plane that someone flies gets beat around a little. But in this case, the Senior is a slow flying and very forgiving plane. So I think it would be OK.

My second plane years ago was the Senior powered by an Fox 40. I added ailerons and it was a great plane.

I taught a student on one a couple of years ago and it was powered by an old ST 40 (round head). It was the red ARF and we nicknamed the plane the red zepplin because of the way it flew. A couple weeks after he soloed and felt comfortable with it he was attempting to land. He got backwards on the elevator and nosed it in from about 5 feet up. The only damage to the plane was the nose gear mount broke off of the firewall.

Once you get infected with the 4 stroke disease you will never be the same. The tach is very useful and I find they are easy to tune and hold settings better than my 2 strokers. The only thing I don't like about my smaller 4 strokers is that they are harder to hear when multiple planes are in the air, especially the big gassers. The only time I deadsticked a 4 stroker was when a valve keeper broke on me and the valve dropped into the engine. Just keep in mind to adjust your valve on occasion.

The only big difference, beside price, between the two is cost of repair WHEN you crash.

As a "newbie" you can definitely plan on crashing. 4 strokes have more parts that can be damaged in a crash. (Don't ask me how I know about that ). The pushrod tubes are especially vulnerable.

I can't tell you about Magnum 4 strokes. From what I have read from others, they are supposed to be pretty good.

If you want certainty get a Saito or OS.

Since there is a better than average chance of stuffing your plane, I suggest a cheap 2 stroke. When you get better, then pay the price. A two stroke can take a better beating into the ground than a 4 stroke.

Hello; I have been using four strokes since '92, Saito and OS mostly, with a few Enya's in there too. I would advise anyone to choose four strokes over two strokes. Once you are over the "familiarise-ation" phase it's all fun. Tuning is no more difficult, and once they are set, you don't have to monkey with them from season to season. I would choose a Saito 50 for your Kadet Senior, or if it's a Senorita I would choose an OS 26. Although I have no experience with Magnum (or any of the chinese brands) I have heard a lot of praise from owners of them, and I wouldn't be afraid to try one.

I use a Magnum .61 four storke on my Kader SR and it flies great with it. It was originally flying with an OS40LA.

I agree. Learn first -- spend later

I just put together a Kadet Senior with a Magnum .91 and it flies great. I am very rarely above 1/4 throttle and I think I have too much engine, especially for a beginner. I did that because I wanted to fly at a low throttle setting for noise reduction, (long story).

I think a 4-stroke, (this is my first one), is just as easy to use as my 2 strokes. Also, although the Kadet will fly nicely with a .46LA, most of the people I know have larger engines in theirs as well. Talk it over with your instructor before you make a decision.

That plane will want to stay in the air if you can't get your engine tuned to run at a low idle, it's like the wings are filled with helium or something.

I know it is more likely that a beginner, ( I am a beginner too, on my 4th plane and seeking an R/C addict's 12 step program), WILL crash at some point but, I really think you would have to almost 'try' to crash this plane once you are soloed and off the buddy-box. Mistakes can and do happen to seasoned flyers as well.

As for 'Engines to avoid'...I know there are probably a few, but most engines will run reliably as long as you care for them and break them in properly. I get sick of hearing guys say...'I'll never buy another____ engine'. It's usually the guy who runs too lean, never bothered to break it in and likes to run 20% nitro at full throttle barely controlling his plane....(No, I'm not bitter...why do you ask?).

I think you will find Magnums to be good engines for the money and you will need to learn about 4-strokes at some point. Just be prepared, as we all must be, to lose your investment. Some of the old-timers at my field say that the only plane that will never crash is the one never flown.

Go fly your plane with full knowledge of the risks invoved and ASK YOUR INSTRUCTOR. He/she will have at least met you and be able to tell better than we can wether you are going to be safe with ANY engine in ANY plane. My instructor has predicted, accurately, which students will be able to learn and which will not. (That is, before they give-up and get an R/C car or truck). No offense intended to those who choose surface R/C vehicles, our club happens to have a full-blown R/C race track and holds regular events.

HAVE FUN!!