Check6

My Feedback: (427)

Magnum seems to have good prices on their 4 stroke engines. I have never owned one. How do they compare with the big name engines OS and Saito? Longevity, starting, smooth running, quality?
Thanks,
Fred

liquid_TR

I tested the Mag 91FS, from break in to idling perfectly took relatively short time.

After the tach readings, and transition tests, I came to conclusion that Mag 91 is as powerful, smooth, economical, easy to start, reliable, long lifed as a OS 91 surpass..

OS 91, looks a little better, as it has superior machining tolerances and a little better quality castings - but this is not enough to justify the price difference..

carrellh

If you use the 'search' function you will find several threads just like this with dozens of replies.

My brother and I have about 6 OS and 10 Magnum four strokes. We do not have Saito. The OS and Magnum seem to have similar power and smoothness. Some of the Magnums needed a fairly long break-in. All of the OS were ready to fly after a couple of tanks. Magnums seem to have a 'coarse' or 'blunt' needle valve. One click can make them much too rich or or too lean. Sometimes it's a little harder to find the 'sweet spot' with the Magnum. This is not a big deal witha lot of planes since many are very overpowered. Just run rich. My brother has a bipe that's pretty heavy and it really needs to be in the 'sweet spot' to fly well for him. During July/August it was tough.

One other thing. He has had two crankshafts break in Magnum 91s. Global has repaired them for free. we cannot totally rule out operator error but he runs them the same as the OS and the OS have not had any issues.

Marcol

Ask yourself why all the Chinese copies are copies of the O.S.


Therein lies your answer.

errie

True Marcol, very True

goirish

I have the 52's, 70's, 91's and the 180. They idle, transition and peak as good as any OS that I have. Will buy more when I get planes to put them in.

Sport_Pilot

Actually some are copies of ST, the Tower engines for example. The early Enya's and OS copied K&B and Fox. When OS came out with their first schnurle engine people were saying they copied HP and Fox, probably just because they had schnurle engines first. And OMG Fox copied the Supertigre carb when he made his MK series carbs. So what?

Marcol

If you read the orriginal post. the comparison was between the 2 companies' 4 stroke engines. Nothing to do with 2 strokes.

bigedmustafa

My Feedback: (2)

I have a Magnum XL .52 RFS and a Thunder Tiger F-91s that I've flown quite a bit over the last couple of seasons. I think both engines are terrific with regard to power, ease of use, and reliability.

Thunder Tiger and Magnum both deserve to be on your 4-stroke shopping list.

ProBroJoe

You don't want me to answer that question right now. [:@] (See the Mag .30 thread a page or so back.)

Long story short, the Chinese engines are hit and miss as far as quality and performance is concerned - i.e. somewhat of a gamble. The few dollars you save won't make up for the time, effort, and frustration you'll go through should you be one of the unlucky ones.

-Joe

Gringo Flyer

My Feedback: (18)

Magnum versus OS. Go magnum every time. They are good engines expecially for the price. They are great sport engines for sport flying, trainers, etc. OS is great too but the price difference is enough to make me choose a maggie everytime.

Magnum vs Saito. Saito engines are lighter, more powerful, and beautiful engines. I like the saitos for 3D planes where power vs weight it important. There are worth the price but on my budget I dont put them on every plane.

I have 2 magnum 91's, one 72, one 1.20. That are on sport planes, trainers and warbirds. They are great for those uses.

I have a saito 125 on my fusion and its a blast. Good fit for a 3D plane. Plus I just like to look at it!

Campgems

Dollar for dollar, the Magnum is my choice. I have had three O.S. four stroke, one I have yet to fly, a 120 Supass II pumper, and two 52 four strokes, RIP for one of them. I also have a 52, two 70's, and two 91 Mag four strokes. There have been two issues pop up with the Magnums, both carb related. One is the stubby taper on the high speed needle valve. The second is too deep groves on the idle mix O ring grove.

For some reason, Magnum put a blunt needle valve in the 52 four stroke, even though the PN for all of there High Speed needles are the same. I swapped a needle from a Magnum 60 two stroke I had into the 52 four stroke and solved the troublesome sweet spot. T

The over cut o-ring groves on teh 52 were solved with a neww mix valve.

I've got a 70 now that is just getting broken in, having survived it's second crash, and the mix vavle on it is loose feeling. I'll replce the O-rings or needle depending on what I find.

These are minor agrevation issues. Paying a $100 to $150 more for the same engine is not a good solution in my mind.

Don

laiosto

I have O.S, Enya, Magnum, M.D. S and thunder Tiger engines.If money is not a limitting factor,always go with the O.S or Enya . My other engines all run fine but with O.S you have the confidence of quality,they always seem to run right first time.The only problem I have had has been with a crappy MDS.61. Until I bought a new Perry carb for it it was impossible to tune. They cheaper the product the bigger the gamble.Simple. For me from now on it will be O.S Engines all the way.

blw

My Feedback: (3)

This isn't true at all. There are some excellent and superior engines out there that are cheap in price when compared with the big name ones. They run rings around the better known and premium priced 'big boys'. Throwing out more money doesn't always get you the best engine.

submikester

My Feedback: (6)

Magnums are great buys for the money, in my experience they do tend to need a bit more attention and a longer break in. My belief is that the carb is not as good as the OS Carb but the rest of the engine is fairly equal.

The OS engines, in my experience tend to be more reliable out of the box - again I believe it is the superior carb that does all this.

I have a few OS 4 strokes when I can afford them but mostly Magnums. 3 of the 91s and 1 of the 61 RFS.

AJsToyz

I had a 70 that was having problems, sent it to Global and no problem , they took care of it. After I got it back it ran like a gem , but it wasen't what I needed. I needed something really light with a little more power , got myself a Saito. I did fly the Magnum on my stick though and it started very easy , idled excellant , and sounded very cool. If I have a project calling for that type of engine , I wouldn't mind having another.

Andy