Geardaddys

Ok.. 4 stroke questions for you fellas.. I'm considering a plane for next year.. will be my 5th airplane (goldberg eagle II, great Planes Electricub, H9 Ultra Stick 60, and a FancyFoam Ultimate Bipe).. I'm pretty comfy with all of the above now and I am thinking of a 60 sized Edge 540 with a 4 stroke which I don't know much about. I see there is a huge disparity in price from the OS 1.20 Surpass w/pump (379.00 at tower) and the Magnum Magnum XL-FS120AR (269.00 at tower). Also considering the Saito 1.25..Is the OS better in quality by 100 bones? I notice that most guys with 4 strokes at the club use OS.. I'm not into the names and brands thing, but I don't like buying junk.. I'll spend more if it's worth it..

Thanks for your opinions!

w8ye

My Feedback: (16)

Stay away from the OS pumper unless you need it. The best things in life are simple.

I have a Magnum 120 and a Saito 125. They turn the same prop mighty close (The Saito has the edge.)

But the /Saito only weighs 3/4 as much as the Magnum

Kimhoff

My Feedback: (22)

You can not compare the price of a pumped engine against one that is not pumped. Mags are alright until you take them apart and really start to look at them. Hey thye run but they are not pretty. If you are in this for the lon rn and plan to re-use the engine after you crash the plane you are mounting this in, make the investment and buy a OS or a Saito. You will be glad in the long run. Take it from sombody who has been there.

GaGeeBees

My Feedback: (23)

The Magnum is a good value for the money. However, I'm sure that the old adage is correct that you do get what you pay for. I have all three engines and have no complaints about any of them.

P-40 DRIVER

The first thing is a .91 4 stroke is the equivelant of a .61 2 stroke so that might be a starting point. The second thing is that you are really dealing with 3 different engines which do different things well. The Magnum has alot less power then the other two, about the same as a Saito 100 and is of lower quality so the potencial for more problems is there; although, they run fine. The OS is the most user friendly, will last a long time and probably have the fewest issues. The Saito is the lightest by far, a little less user friendly then OS and likes a little more nitro to get the most out of it. The pumped OS .91 and 120 surpass engines are really nice, if you can afford them, but not required. For general sport flying in the long view, you will probabley be happier with the OS as a first 4 stroke.

captinjohn

Go Saito...and don,t look back....very high quality...if you cannot tune engines...have some person who does help you. Capt,n

Gringo Flyer

My Feedback: (18)

Depending on what edge you are considering change what engines you run. Is it a 3D style flyer or more of a general sport flying acrobat?

The vectorflight edges flew really nice on the 91 FS.

The big plus with the Saito is that the 125 weighs about what the OS and Magnum 91's weigh. I think the magnum 4s are good buys. The 91s match up well to the OS 91s. The 120 is a good engine but a bit underpowered. I think they are a good bang for the buck though because they are cheaper than the other engines and they run well on lower nitro. I just bought a NIB magnum 1.20 for $199 on evil bay. Thats pretty hard to beat.

I also recently bought a Saito 125. The Saito is going on a OMP Fusion for all out 3D performance. So the power and lower weight engine are a big plus.

The magnum I just bought is going on a TF P47. More of a scale flyer where all out power is not a top priority but a good running engine at a good price is.

So IMO it really depends what you are looking for... all these engines have there place (except for the OS which is way overpriced)

Gringo Flyer

My Feedback: (18)

I dont want to change the subject of the thread but I since I have both of these engines NIB I would be interested what numbers you are getting on these.

w8ye

My Feedback: (16)

I don't have a tach at this moment. My TNC has gone dead. All I can say is that they seem to be running good. I've run a 15-8 and 15-6 on both engines. They seemed to both pull the 15-8 fine.

blw

My Feedback: (3)

The neighborhood of 9400 on my Saito 1.25 with an APC 15x6. Gringo, it hauls my Epsilon 60 around like no tomorrow since I know you have this kit too. Almost all vertical lines at 1/2 throttle or less, and it is on its first gallon of fuel right now.

I have to disagree with the comment about Saitos needing a lot of nitro to get more power. 15% is plenty fine for me.

Gringo Flyer

My Feedback: (18)

blw I forgot that you had one of those. I just recently bought one. Its going on a OMP Fusion. If the Saito hauls the Epsilon around good its going to be fantastic on a fusion.

angrycookieman

Yeah, Saito all the way. The OS engines are nice but you can't beat a saito for a four stroke. They even sound a little tougher to me. My saito 100 yanks the ultra stick 60 around like it's not there. Do the research and you will see why they are so popular. Now if you wanted two stroke, the OS would be my choice.

w8ye

My Feedback: (16)

been around a OS 91FX Tower 75, and a OS 120AX this summer. They have run flawless.

I've been running a OS 52 Surpass and Saito 50 and 56's this flying season and they have run good also.

Hobbsy

My Feedback: (102)

Barry, did you mean an APC 15x8, a couple of days ago I was testing with a TurboHeader on the 1.25 and put an APC 15x6 on by mistake and my 1.25 turned it 10,450. It turns an APC 15x8 at about 9,250.

Gringo Flyer

My Feedback: (18)

Hobbsy what boost are you seeing with the turboheader?

Hobbsy

My Feedback: (102)

GF, there is no discernible gain on the 1.25, most likely due to the huge pipe and muffler that come stock on the 1.25. The turboHeader does give the 1.25 a very distinctive, deep sound. As you can see in pic. #1 the stock muffler is huge.

NM2K

My Feedback: (14)

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I'm curious as to why you are not comparing the unpumped OS FS-1.20's price to the other unpumped 1.20's? That would make more sense. Yes, the pumped model is worth more money easily, but you are comparing apples to oranges, unless I missed something.

To me, this is just my opinion, the Magnum 1.20 is way over priced. It should be selling for around $200 to $225. It is not in the quality league of Saito or OS - period. It is a usable engine and it does a fair job, but it is not the long lasting engine, nor power producer, that the OS and Saito 1.20's are. The USA importer still has his head in the nether regions concerning their four-stroke engine prices.

RCU is a haven for Saito enthusiasts. I like both brands of engines, OS and Saito, but I do not see any "clear advantage" to owning a Saito over anything else. Yes, they weigh less, but this lower weight comes at a price - increased maintenance, as one would expect for a lighter engine producing the same power at the same rpm as its heavier competition. Rossi engines are heavy for a reason. That same reasoning applies to four-stroke engines as well.

So, if a few ounces less weight are more important to you than greater MTBF, buy the Saito. If you're not a 3D enthusiast and the weight of an OS is just fine, why not enjoy the longer MTBF (Mean Time Before Failure) of an OS? I have both brands and I use them in the situation that profits most from their particular advantages.

Ed Cregger

blw

My Feedback: (3)

Dave- now you have me second guessing myself. I'll have to pull the spinner and look again. Maybe it is a 15x8.

Ed- what do you mean about higher maintenance on these engines?

youngun

Then you will want to read up on all the problems - especially in regard to Saitos vibrating.

Some try to down play any problems with a Saito - I'm guessing because Saitos cost so much and many believe that the high cost automatically makes them good. And this couldn't be more wrong in this case. You do not get what you pay for with Saito. When you have problems, usually the only help you can find is on these forums. And I haven't found anyone yet that can tell me what is wrong with my Saito 100, or any way to fix it. There are many well meaning people that say adjust, adjust, adjust. But mine has been adjusted, adjusted, adjusted - and adjusted even more. Bottom line - problems can't be adjusted out of a bad engine.

My advice - would be stay away from the 4 cycle engines until you can find one with all glowing reports. And most important - one that does not vibrate - ever. The vibration problem is more important than some small difference in power. Good engines, with a balanced prop, NEVER vibrate. And also - looks can be deceiving - anyone can polish up aluminum to look shiny. How it runs is what's important.

I lucked out with a Saito 1.20. It never vibrated. It turns a 17X6 APC prop at near the max RPMs listed for this engine. If you're interested - look up the specs on the 1.20 engine and subtract about 500 rpm and you'll have it. That's what I remember.

On the strength of that 1.20 - thinking it was a typical Saito - I bought two more - a 1.00 and the, then new, 1.25. There were already many reports of vibrating 100s. Being the optimist I am, and I was always good at tuning engines, I was sure that any problems could be adjusted, or tuned, out of it - WRONG! Then the reports started rolling in about the 1.25. - many with the same vibrating as was reported with the 100.

My 1.25 is still new in the box - and will be sold without any running by me. The reason? I now have first hand experience with the 100 and it isn't good.

Here's a thread about it if any are interested. [link=http://www.rcuniverse.com/forum/m_6477274/anchors_6477274/mpage_1/key_/anchor/tm.htm#6477274]Saito 100 problems[/link]

Anyone trying to down-play or minimize vibration problems is doing a dis-service to fellow modelers and flyers. It's a serious problem that will crash you plane, given time. And when it goes down, it could hit someone. None of us need that.

Any that want to argue about this - find somone else! I'm not arguing. The facts stand and can't be changed, or wiggled out of, by a bunch of rhetoric.

Buying a Saito - you may get a good one like my 1.20 (which they discontinued, by the way ). Or you may very well get a vibrator. I don't know the odds - for you gamblers out there. But many reports are there, and they are just what a few people took the time to report on the internet. I'm sure there are others that haven't been reported.

Buyer Beware!!

Hobbsy

My Feedback: (102)

Young, you're the one who needs to read more, Saitos do not vibrate more than any others when the needles are set correctly and there is no way they require more maintainance, They simply need fuel and a plane to haul around.

NM2K

My Feedback: (14)

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How often do you hear of OS users replacing valve springs, rocker arms, ball bearings? How many times have you seen an OS four-stroke swallow a valve? Or have a bent valve stem?

If a person lives and operates (flies models) in an area where Saitos are most popular, it is reasonable to expect a person to go along with the crowd and favor Saitos. But I've been to other parts of the country where many clubs are lucky to have more than one or two Saito engines in the entire club. So, popularity varies according to region/locality. You would not be able to determine this to be true just by reading RCU's heavily Saito biased engine forum.

I have never had ANY problems with my four-stroke OS engines. But, to be fair, I've never had ANY problems with my Saito or Enya four-strokes either.

However, do a poll on RCU and I think you will see that Saitos are far more problematic than OS engines, if you use RCU as your sole database. Ever since Saito changed their designs and then changed those designs to accommodate more nitro, they have not been equal to their more solidly built predecessors. Just my opinion.

I'm not Moses, so nothing is written in stone that utters forth from this keyboard, nor am I trying to get anyone to switch brands of engines. I own all brands and I wouldn't want to give up any of them. But I get a little distressed (worrying about others' ability to perceive reality) when I see folks acting as though Saito is the only engine to own. It simply isn't true.


Ed Cregger

Gringo Flyer

My Feedback: (18)

I was planning on buying one because the advertisement claims around a 200-300 rpm boosts. Thats pretty substantial on a 15X6 prop on a 3D plane. But it sounds like I will just stick with the stock muffler then.

blw

My Feedback: (3)

I'm not sure of what design changes you are talking about here, Ed. Compression used to be higher on them. You can still run them on very little nitro and they run fine.

youngun- I've suggested a couple of times that you change your cam gear back to the way it was when new. That may be where all of your problems are.


edit for grammar

NM2K

My Feedback: (14)

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I'm talking about bent valve stems, busted rocker arms, ball bearing replacements, fixing intake manifolds that are problematic. You know, all of the things that are listed right here on RCU in the Saito engine forum.

How many times have you seen anyone say these things when compared to OS? The ratio is definitely in OS' favor.

To be fair to Saito, a lighter engine will appear to have more vibration than the same size/power output heavier engine. It is simple physics. If you go for the lightest engine, expect to experience more apparent vibration. Yes, if not dealt with properly, it can damage a fragile model. If dealt with properly, it can be acceptable, but the difference in apparent vibration (what the model sees that has not been damped by increased engine mass) can be a very real problem for some folks. Again, I'm not saying that the engine is vibrating more than its heavier equivalent. I am saying that the same amount of vibration is not being damped with more engine mass.

I know it must be impossible for some folks to believe, but lightness isn't everything except to those flying competition or 3D. The vast majority of steady R/C'ers, those that will still be flying in ten years, fly 3D with much more relaxed standards than some of the super enthusiastic butterflies in our midst.

Ed Cregger


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Again, this is just my opinion - when Saito switched to the lighter engines utilizng non removable cylinder heads is what I'm referring to, Barry.

Remember back when they used to go to the trouble of putting a bushing(s) in the connecting rods? Those engines were the good ones in my book. The later stuff is cheap goods sold at high prices by tons of marketing hype. Anything will crank up with lots of nitro. Let's go back to the days of using 5% nitro truly see who comes out on top.

w8ye

My Feedback: (16)

There's most likely tenfold more Saito's in service than OS four stokes?