jamesroutledge

I had a very similar engine to Fiery's , a Magnum Pro 45 which ran like crazy , but regrettably was totalled in a crash.
I eventually drew a blank on getting a spare crankcase and built all the undamaged parts over into
an old OS FSR 40 crankcase. It took an evening of machining, but now it's my "cheat" engine, packing way more punch than a standard FSR 40.

skrez

My Feedback: (15)

Hi Guys,
Just purchased my 1st Magnum, a XL-91RFS . Brand New in Box. Really got a good deal on it 120.00 shipped to my house. Have you had good luck with this motor? I`v owned Saito`s and YS in the past, but for 120.00 could`nt past it up!
Frank

tkline

I've got three of them in .60 sized warbirds and they do a great job and are very dependable.

skrez

My Feedback: (15)

That`s what I bought in for, 60 size warbirds. What warbirds are you flying and what prop are you using with the 91`s?
thanks,
Frank

tkline

I have them on a top flite AT6 a hanger 9 corsair and a hanger 9 hellcat all running 15x6 master airscrews on 15% powermaster fuel

N1EDM

My Feedback: (2)

Hi Everyone,

Someone donated a NIB Magnum GP-44 2S engineto our Club for use in a trainer. All of the parts are there except for the Needle Valve.

Can someone point me into the direction of where I could find one, or if you have one you'd like to sell, could you let me know? I'd like to get this engine into one of our trainers to replace its aging OS 40FP.

I presume that a 10x6 or a 11x5 is the go-to prop for this engine on 10% nitro??

Thanks a lot,

Bob

The Raven

Cam timing is simple. Set the piston at TDC or BDC, then line the dot on the cam so it's aligned with the pushrods.

The Raven

OS needles generally fit....at least on the four strokes.

N1EDM

My Feedback: (2)

Thanks for that, Raven, but this is a 2-Stroke. I see the similarities between OS and Magnum and I also see differences. I am not comfortable using the needle from one manufacturer into the carb of the other. The two needles have different tapers which could lead to problems.

I wonder if I used a OS carb that had the right throat diameter???

Still and all, I'd prefer to use an original needle valve for this magnum GP-44 if one could be found.

Thanks,

Bob

The Raven

Just compared an old ASP 40 needle with one from an OS 40LA. Identical to the eye and both fit either engine.....and I've swapped OS/Magnum needles before (albeit not with your specific engine type).

I understand you're concern about different tapers etc, but believe me they do swap and will work fine. Provided you can tune the engine adequately, a slightly different taper (if it exists) isn't going to hurt anything.

Most engine manufacturers use an industry standard angle because it simply suits the machining processes. Who's going to spec an specific odd taper?

Using different carbs may work, but if you think the needle makes such a huge difference why consider swapping a whole carb?

Yes, I'd like to use an original needle (like you) but I wouldn't get carried away hunting one down if a common OS part fits.

N1EDM

My Feedback: (2)

Thanks for that, Raven.

As far as the carb swap is concerned, if I have a OS carb that has mounting dims that will fit the Magnum, then the it won't hurt anything - the engine will either run great or poorly.

My worry is that with a HSN that isn't the same taper as the socket on the spraybar, things could gall up. But it bears consideration.

Thanks for that,

Bob

The Raven

Yep, you're wise to consider it. However, I'd suspect the taper is fairly standard for ease of manufacturing. Probably some easily divisable angle.

airborne14830

I have recently gotten a mag 1.20 2-stroke on an ultimate120. During break-in it seems it will not hold pressure in the tank, and on the low end the engine will quit due to no back pressure in the tank thus no fuel to the engine. Does this engine requires a fuel pump to eliminate this problem? the tank has been rechecked and is not leaking.

N1EDM

My Feedback: (2)

If you have the engine set up so that the pressure line is running to the tank directly from the muffler, then the tank will not hold pressure when the engine is not running. This is normal. I don't know if I've answered your question or not, or if you had something else in mind for that 120.....

Just my $.02

Bob

airborne14830

Yes the pressure line is from the muffler to the tank. when the engine is running at full throttle it runs fine, but when I chop to low throttle the engine runs for less than a minute and quits with plenty of fuel still in the tank.

N1EDM

My Feedback: (2)

Thanks Airborne... my point was that unless you had a check valve in line, your tank is not going to hold pressure when the engine shuts down. It will just vent out to the muffler. Or, did I read your post wrong and just make a complete idiot of myself by answering the wrong question....

Bob

airborne14830

My question is that the engine will not idle. It runs fine at full throttle, but when you go to low throttle to idle speed it quits like there is no back pressure in the tank. The tank is not leaking and the tank cap is on properly. Also, each time I go to start the engine I have to place my hand over the muffler exhaust so the engine will start up. I heard about opening the Low speed end cause new engines may have been closed more than normal, and the use of a check valve on the exhaust line, which I have never seen done before.
Your thoughts and thanks

N1EDM

My Feedback: (2)

I am thinking that the low speed needle (aka LSN) is just not adjusted correctly. If you can keep the engine running for a few seconds at low throttle (before it quits) perhaps you could pinch the fuel line going into the carb. If the engine speeds up, then the LSN is too rich. If the engine dies immediately without speeding up, then you are too lean and need to richen it up a little.

Low Speed Needles are a little tricky to adjust in that you should only adjust it about 1/8 turn at a time. It just takes a little patience and a little time. Give this a try and let us know how you make out.

Bob

Angi_H

I have a magnum GPA .46 and I need a carb for it what can I sub for it? It's going in a old kit I just started a mark eagle 2 kit.
thanks
Angi
KF5ULI

jstanton

My Feedback: (14)

I believe a carb for a OS46LA should work for it. I would take it to my LHS and see if they will let you try a carb for a OS46 on it. If it fits it will work just fine. Good Luck. You could also try a Perry Carb on it. They are good carbs also.

N1EDM

My Feedback: (2)

Hi everyone, it's me again...

I'm rebuilding a Magnum XL-91 2-Stroke engine. I'm having a helluva time finding head gaskets for it (p/n S91112). I tried an OS 91FX head gasket just for fun but it's much thicker than the two S91112's that are called for and slightly larger in diameter.

Also, can anyone verify that the Magnum woodruff key (Magnum p/n S91218) is the same as the woodruff key that's used on the 91FX?

I just can't seem to find anyone with stocking parts any more. I found a woodruff key at Hobby People but no gaskets (which are what I need mostly).

Thanks,

Bob

Prop_Washer2

My Feedback: (26)

Harbor Freight has a complete selection of Woodruff Keys for a few bucks, and an ASP Brand motor's parts will work as well, they are the same engines... I found these links in 10 seconds...

http://www.gravesrc.com/category_s/247.htm

http://globalservices.globalhobby.com/part/210970.asp

I believe you have an XLS-91...

http://www.amazon.com/Magnum-Parts-G.../dp/B001AETNG2

http://www.globalhobby.com/public/mfr/MAGXLP24.asp

N1EDM

My Feedback: (2)

Thanks. I didn't know about APS and never thought to check Amazon. For some reason, neither Graves or Global Hobby showed up when I searched in Yahoo or Google.

I appreciate it.

Bob

Ernie Misner

Yes, ASP......

N1EDM

My Feedback: (2)

...my bad