Magnum engines
 

I was thinking of buying there 70 size 4-stroke is it any good what is up with this brand? please tell me what you know.

Flyer 202[8D]

RE: Magnum engines
 

There have been lots of positive experiences posted about the Magnum 4 strokes. Many appear to consider them a safe choice and a good lower cost choice than OS or Saito.

RE: Magnum engines
 

I agree w/ Piper --2-91s -- no problems 'cept when you run strait synthetic fuel thru it when the book states not to, but you know it all and lock up the engine like an idiot. :( Advice --10%nitro/18% oil 2-stroke fuel ; any flavor. They like a l'il castor oil w/ their nitro.

RE: Magnum engines
 

I have one of Magnum's .52A XLS 2-strokes, and it runs absolutely great. Based on my Magnum engine experience so far, I'll definitely be trying one of their 4-strokes in the future.

RE: Magnum engines
 

Magnum .91 good, Magnum .70 not as good. Magnums are generally heavier than OS or Saito, but if your application can take an extra ounce or 2 then they are an excellent value.

I have a .46 2 stroke and a .91 4-stroke. I avoided the .70 because 4 people at one of my fields had trouble with them. There are no-longer any Magnum.70's in-use among the people I fly with at any of my 3 fields (but I only fly with a few people from each field).

RE: Magnum engines
 

I am going to put this into a 40 SIG Mid Star so no power to wheaight issues.

RE: Magnum engines
 

The consensus at our club seems to be Magnum 4 strokes are good, Magnum 2 strokes are a mixed bag.

RE: Magnum engines
 

The 91 is great for the price. I have it in my Top Flite 182. Flys it just fine at 1/3 throttle for scale flight. The 120 is on my Skybolt it is a POWERHOUSE!!! Stump pullin' SOB, that engine is.

RE: Magnum engines
 

I have a 52 magnum 2 stroke that i love never had a problem with it and it rips...however a friend has a larger 2 stroke that is junk....the 4 strokes seem to run well though..i dont know anyone that has had a 4 stroke for long term so i dont know how long they last but for the mean time they seem to run well Kieth

RE: Magnum engines
 

I've been running a Magnum 70 on Power Master 10% sport fuel part synthetic part castor. Runs really good. It is heavier than a Saito but about the same weight as an OS Surpass. I've never had any problems with it i run it inverted with a OS F plug.

Dennis

RE: Magnum engines
 

I have a magnum 61fs and a magnum 91fs and been running them for 3 yrs... Never a problem... Not as much power at my Saitos and heavier... but for what I use them in it doesn't matter and they run excellent...

RE: Magnum engines
 

I have a Magnum 52 and I'm having trouble getting it to come down to an idle. Still breaking it in, but wants to keep the rpm's up. Someone suggested swapping out the carb.

RE: Magnum engines
 

How is it mounted ?
what fuel and plug are you using?

RE: Magnum engines
 

I have one of the Magnum 70 4 strokes, I ran one tank through it really rich, on the second tank I leaned it to just under 9k and adjusted the low speed needle, idle and trasnition was good so I gave the plane a test drive. It ran great, after a couple of flights I leaned out both needles again.
This is a cowled engine, APC 13x6, 15% nitro, 10200 rpm sustained, runs great, no overheating problems, idles perfectly.

I also have 2 91's and a 61 that run perfectly too, my next plane is a Hog Bipe and I have a Magnum 91 in my tool box for it right now. I think the Magnums are an excellent value.
Lots of people elude to the Magnums being less powerful than Saito and OS, I do not own any of the Saito engines so I have no opinion on them, but I do have an OS 91 and a 70 and with the same prop and fuel the Magnums get an average of 600 rpm more than the OS engines.

RE: Magnum engines
 

Im using using an OS 3, mounted upright.Carb and tank are level. Using APC 10x8 prop. I ve run a gallon through it tweaking it here and there. It just doesn t want to come into a decent idle.

RE: Magnum engines
 

cmstone

don't give up on it until you have run at least a gallon of fuel through it, mine gets better with every tank I run. Just keep it slightly rich and fly it. I put mine on an Alpha 40 trainer that I used up the Evo 46 on, it sounds better, and doing touch and goes keeps getting better and better. I will have trained 3 people to fly on this bird so far...

RE: Magnum engines
 

I have it mounted on my Somethin Extra, and haven t been able to fly much this year. But so far its coming in pretty decently.Just glad the SSE deadsticks well :)

RE: Magnum engines
 

I agree that the engine may just need more run time.
The "rules" say the tank and the carb have to be level for the engine to work correctly.
However my personal experience has been that my engines work best if the tank is lower.
Many of my planes have the tank stopper centered in the engine mount hole, with the engine mounted upright this is definitely below the carb, all of these engines run really good and will idle indefinitely.
If you cannot get a good idle after a gallon of fuel you might try lowering the fuel tank.
I will probably get flamed for that suggestion but I know what has worked for me.

RE: Magnum engines
 

Thanks for the suggestion.I ll keep it in mind.But the weather here has turned into winter finally.So it may be a few months before any decent weather can be had to fly.So, for now its building season.

RE: Magnum engines
 

I would take this as the opportunity to check the tank height as previously suggested. You can take it outside to idle test it, if you don't freeze, it might look like an opportunity to fly it too....:D

RE: Magnum engines
 

Yeah, I guess I could go waste the fuel :) irritate the wife of course

RE: Magnum engines
 

Change to an OS "F" type plug. Also, you are somewhat underpropped, and that will show particularly on idle. I run APC 12X6 on my Magnum 52 RFS in a SIG Rascal 40. A stock SSE has short landing gear, and you may need to do something with that to better match up the plane with the engine.

RE: Magnum engines
 

I knew I would have to change the prop out. But just going with the recomended break in prop. I ve been looking at changing the landing gear out. Its a real pain on the grass, wants to bounce and wobble.Need a little wider/taller gear for sure.

RE: Magnum engines
 

Change your plug to an OS "F" plug. Im running a Master Airscrew 12X6 K Stroke prop on my .52 RFS. Move up to a 20/20 fuel and it will run like a watch. Also, Ive noticed on my magnum 4 strokes (I have 4) that after the first gallon or so of fuel the valves need adjusting. You might have to do this every gallon or so until you get about 4-5 through it. Enjoy, my magnums have been great performers and I have NEVER had a dead stick on any of my magnum 4 strokes. I cant say that for the few Saitos and O.S`s I have owned.

RE: Magnum engines
 

Adjusting valves seems to be a very popular past time and I am not opposed to it at all if there is a reason to adjust them. I have never touched the valves on any of my engines. I think the oldest one just completed its 3rd flying season, with many gallons of fuel run through it. Purrs like a kitten at idle and roars like a lion at full throttle. My theory on engines is don't mess with it if it is working correctly. If it won't idle or if the power is not up to snuff that would be plenty reason to check the valves.