Ok I see magnum is making 4 strokes again so my question is what engine would be a better choice for my astro hog?.91 or .70,I want it to ballance with out using any weight if that helps.

Thanks

a guy at my club has a astro hog with a saito 70 in it and it flies nicely, I would put a .91 in it if it was mine

well magnums are heavy, the .70 weights 21.2oz and the 91 weights 22.4 oz. so if you can handel the 1.2 oz more i would go with the .91. if not the .70.

My experience with Magnum 4 strokes is not that hot. I tested a .30 and a .52 and neither would idle and transition well at all. I did get the .52 to work OK not great but better by shimming the valves.

In case you didn't notice, Hobby People currently has Magnums on sale. I think they are all about $30 off.

Good luck

Magnum is a great engine. They operate as easily and reliably as O.S. Same performance as O.S. only about a $100 bucks more affordable in most all cases.

I'd go with the .91 if I could.

I wouldn't recommend Morgan fuels with Magnum though- even though they will run using it. My experience isn't the same as everyone else's, but I've found they run better with Byron and Power Master. I don't know why.

Saito 82 is a good choice

I have several magnum engines, they are great engines. I have a friend with a magnum 180 it is just as reliable and runs just as well as my Saito 180, and the magnum drinks half the fuel as my Saito.

I'll second the 82.

Bob

Saito 82 $299.99
Magnum 70 $149.99
Magnum 91 $169.99

That difference is HUGE. I'd guess that price is a factor for many of us who run Magnum engines. I have four Magnums and they all run very well. I have no Saito engines. I do have three OS four strokes, and like them very much. All of them were "deals" I stumbled into, otherwise I would not have them.

cowboydfk,
the Astro Hog in my avatar had an OS 70 Surpass 1 witha 13x6 MA K Series prop. At that time I was using fuel with 10% nitro. On a grass field, takeoffs at about half throttle did not use up a huge amount of runway. There was plenty of power to do big round loops but it definitely did not have "unlimited" vertical.

My brother has a hog with either a Magnum or OS 91. He likes the performance of his plane better than he liked mine (flying one immediately after the other) but he never thought my plane was under powered.

Anyone that knows anything knows the Hog can't get off the ground without an OS .91 in it!!! Truth, you get what you pay for but buy what you can afford. Some people even get lucky and find a good running Magnum, they come up on sale at Hobby People all the time for $150.00, not a bad price for a .91, they sell a lot of them, just not to me!!

That just means more for me!

I started out with an OS 70 4 stroke on mine. Everyone told me to "open it up". I told them it IS opened up!

I parked it until my new OS 91 surpass 4 stroke arrived and I have never looked back since. Use a 14-6 apc prop and the 91 pulls the Hog around with authority. No oily mess to clean up afterwards either with the 4 stroke.

Well I guess it's gonna get a .91 then,either os or magnum I can't get a good deal on saito[&o] just hope I don't have to add weight to the tail.

Well it looks like the engine I had for my hog,.61 abc super tiger has more weight then either 4 strokes,it is 26.7, os .91 surpass is 24.2 and magnum xl is 22.4,wonder why manum is lighter then os?

From what I've read you cannot always trust the weights that are listed on the web sites. Unless you've weighed them yourself, or know someone who has, it is really just a guess.

I was just joking about the make of the engine, almost every hog I have seen has had the OS .91 in it though but that's just because the OS was the top four stroke engine where I came from. Here in NV it seems like the number one four stroke engine is the Saito or YS. A lot may depend on what the LHS stocks and sells or what is used at the field you fly at. In my area there are a lot of IMAC pilots too, not sure if that means anything but a lot of them are using the YS.

I weighed all mine , then lost the paper I wrote the weights on. [:@]

That's what my shop wall is for!!

I've owned both the OS and Magnum...I got rid of the OS due to valve spring issues...Never bought another OS 4 stroke since...

To be fair this was awhile ago, about 7 years or so...If I had a need I may buy another OS 4-Stroke as I haven't heard of this problem in a while...

On the other hand, my wife's 60 size trainer has a Magnum 91 in it since 2005. It was 4 years old then (bought in 2000 or 2001). Runs very reliably year in and year out...

Larry

Hello Cowboy, I have a Thunder Tiger 75 in mine and it flys very well.