Hello, I have a 4* 40 and I want to use a 4 stroke. I currently have all 2 strokes. 2 O.S .40s, 1 MDS 40, and 1 supertigre 40. All run great and start on the electric starter immediantly. How hard is it to maintain a 4 stroke? Are they reliable. How hard are they to work on? I am looking at the Saito .40-.50, O.S FS-52, and the magnum XL-52rfs. Thank you for your input and for the help as I dont know much about 4 strokes.

I really like 4 strokes as I bought my first one a little over a year ago. I was a little nervous about getting it after all the horror stories I had heard. After having the engine for a year and probably 150 or so flights on it I have yet to have a deadstick. Runs great. I just followed the manual to the letter. I just recently bought 2 more 4 strokes and plane to eventually sell or trade most of my two strokes for 4 strokes. I really like the sound and prefer the throttle response.

For your 4 star a 52 will fly it but I would really look at a 72 size. When choosing a 4 stroke you have to choose a higher displacement to equal the same power of a 2 stroke. Generally speaking a 72 4 strokes equals a 40 or 46 2 stroke and a 90 to 110 4 stroke equals a 60 to 90 2 stroke. That is speaking in very general terms but that is a basic rule of thumb.

Go for the 4 stroke, you will be pleased.

My 4*40 kit should be here tomorrow. I have a Magnum 52 for it, all ready broke in on the test stand.
This is my first 4 stroke and it has been the easiest to tune. It may be under powered for this plane, but they don`t weigh much so it might be a good combination.

Personally, I'd go for the Magnum .72. They're on sale for dirt cheap right now and they're every bit as good as the OS. I have a bunch of Saitos which I love, but I don't know that I'd invest the extra money.

Make sure you take time to break it in carefully and it will be a wonderful engine for you.

-Scott

A 50 size 4 stroke will pull that plane around just fine. A 70 would be overkill.

Just like low@slow said, a .52 4-stroke is plenty of power for the 4*40.

I have a 4*40 that's been busted and repaired a couple of times, so I know it's a little on the heavy side. I have a Magnum .52 4-stroke on it and it goes like a bat-out-of-heck! Plenty fast and it will do any aerobatic I ask. Spins, snaps, knife-edge, whatever. I haven't figured out yet how to hover, and it might not have quite that much power, but I'd be afraid it would break it with a bigger engine.

Personally, I don't see what all the hub-bub is about 4-strokes.

They are a little DIFFERENT than 2-strokes, but I really don't see them as "more difficult".

You will need to bump your nitro up to 15%, which will cost a little more, but they burn a lot less fuel.

And God knows they are a LOT less messy!!!

Nowadays in the few times I use a 2-stroke, I'm just grossed out by the slime they leave behind.

Darn, I just bought a case of 10%. With so many different opinions on nitro content, I figured 10% would be a safe bet. I could add a little octane boost I have laying around for the drag bike, probably blow the head right off.lol J.K

With only 20 or so flights under my belt, I find my need for speed does not apply to learning to fly my LT40 or my Cubs. Nice and slow seems really fast to me right now and for 3D the G3.5 works great, I love the little red button.

I`ve read quit a few articles on the 4*, most were powered by your run of the mill .40 size 2 cycles and flew very well. So that's why I thought the 52 would be a good fit. And after the ease of breaking in the fourstroke, I`m switching over to them. And MinnFlyer is right, they do run cleaner.

Got to agree with Minn here. The biggest thing about 4-strokes is that it's a bit harder to "tune by ear". Get a tach to help tune the motor until you train your ear to hear the changes. Other than that they're just as easy to operate as a 2-stroke is. And yes, they are cleaner!!!!

Ken

A guy at our field has that setup a four star with a .52 4 stroke and it flies great, I dont think it would hover , but its not meant to, but it has Plenty'O'Power...Rog
I dont know about them myself but with those funky exhaust pipes I imagine they throw the spent fuel away from the plane better so they are less messy or perhaps the unburnt fuel helps to dissolve the goo on the plane..

I had just asked the same question about a week ago or so, kind off. I was asking about the four strokes since I have all two strokes and I have heard about how hard they are to tune and keep running. I was asking about the four stroke for a 4* 60.

I did buy a O.S.91 four stroke and put on my 4*, the only reason I went with O.S. is because all my two strokes are O.S. and they all run great so I wanted to stay with O.S. So I am not saying O.S. is the only way to go, but I am very happy I did.

I did the break in just like O.S. says to do with out one problem. After break in I started to fly it and I only have 10 flights on this four storke, since I just got it ready to fly last Sunday, but so far it runs perfect and it sounds great.

I would say go with a four stroke you like and you will love it and they are not really any harder to run than your two strokes. If you have not heard this before, you will, and that is once you run your first four stroke you will be buying more. I have heard that and I am buying more, they are worth the extra money.

Wow, thanks for all the responses. I will stick with what Sig says and get a .52. Now the only question is which brand???. Thank you

Ut oh, now you went a did it. There well be Saito , O.S, Enya, Magnum ThunderTiger and Y.S guys at eachother throats about that question lol

Four strokes run just fine on 10%, Don't get sold on that high nitro BS.

[quote]ORIGINAL: jagnweiner

Personally, I'd go for the Magnum .72. They're on sale for dirt cheap right now


If Magnum Engines are for sale dirt cheap, can you please tell me the links or websites for those? I think the manufacturer is the same for Magnum and ASP.

Thanks

Mody

Armody-

There may be multiple places with the sale price, because it is apparently sponsored by Magnum. I know that Hobby People has the sale. Website is www.hobbypeople.net. The sale runs through April 1. Tower does not have them on sale, but with their end of month sale, they could probably be close in price.

They are backordered at Hobby People, but it appears they will honor the price if ordered now. 52 is $119, 70 is $129 and 91 is $149. Those are incredible prices for good 4 strokes.

-Scott

I've run my Enya 53 and OS 70 on 10% with no problems--starting, idle, transition, nv adjustment all seem fine. Jim

I have heard you have to adjust the valves every once in awhile? How hard it this.

Very easy. You just take the cover off the top (dont know the official name of it) of the rockers and adjust the clearance with a spark plug gap measurer (not sure what that is called either). You are supposed to check the clearance before breaking it in and then every 10 or so hours of flight. Its pretty easy.

That would be the valve cover and a feeler gauge...Rog

My 4*40 currently has a Saito 45. Definately not overpowered, nice gentle flier. Saw another fly with the Magnum 52 and it did well. You may want to consider how/if this engine will be used in the future. If you went with Saito 72/82, you won't lack for power and your choice of future planes is wide open. In comparison, the 45 is more limited as to working well in other planes, slightly heavy compared to power output. I think the 56 or 62 would be a whole lot of fun.
Have fun, MikeB

There you go.

I could of given you the names in spanish though

My thoughts exactly. It will fly with well with the 52 but a 72 sized 4 stroke gives you a lot more options in the future and will be fine on the 4*40. Also for puttin around the sky unless you are wanting a higher performance 4 stroke for later down the road I would go with one of the more economical 4 strokes. I really like the magnums. The run great and are a great bargain. They also run great on 5%.

Thanks Scott for telling me about the website, hobbypeople are really offering good prices. Well, I hope I would be able to buy it from there or from my country. It's been a month I have been seriously trying to buy a 4 Stroke engine.

I have used on 2 stroke engines, I know one thing, once 2 stroke starts bothering they turn out to be a real problem, pretty hard to set them running good. About 4 stroke I heard that great Idle and best transition. Similary I've been told that 4 strokes are real Headache, once they start bothering you, then no way you can fix them. Specially their needles. I know there is one carb needle, other needle below it I saw and honestly I don't understand what does that needle do. I really wanna buy one 4 stroke engine and check it, that 4 strokes do run without trouble and they are not a HEADACHE, much better than 2 strokes. Should I really go for a 4 stroke? as I wanna buy ASP or Magnum which are same .91 4C engine for my 60 size easy sport. I would like to know the Pros and Cons of 2 Strokes and 4 Strokes. If I have repeated it, sorry for that.

Thanks in advance for recommendations.


Mody

10% nitro is fine for 4 strokes, I used it for two years before I got a deal on a couple of cases of 15%. The 15% fuel gave me 500 - 900 extra rpm depending on the engine so I will stick with it from now on, but the 10% worked fine.