Magnum 25XLS?

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Big Dog
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Re: Magnum 25XLS?

Post by Big Dog »

BTW at HC prices I can go electric before I spend $130 for an OS
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Blue Note
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Re: Magnum 25XLS?

Post by Blue Note »

Got my Magnum 25XLSs today. Look good. Eager to test them out...
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David Drowns
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Re: Magnum 25XLS?

Post by David Drowns »

Mine should be in this week. I hope it's as good as the test engine we got to fly. It was impressive.
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Re: Magnum 25XLS?

Post by lightning »

Mine arrived today. It's on a plane (after I took it apart to see how substantial it looked inside - I was quite impressed).
I like how everything is hex head bolts, not Philips. I like the OPTION of a remote needle valve.
I LIKE the removable prop backplate (unlike their 15XLS which is a press-on) and the fact that the mounting holes are the same as a 25FX. Again, unlike the 15XLS which has different hole spacings from the OS LA15.
Looks good.
Not sure about the break-in instructions saying it needs 45 minutes of running before it goes in the air though.
I have a feeling it might fly rich for a few flights!
Does anyone have a spec on the power output? I can't find mention of it in the paperwork. I am curious to compare it to the published .84HP for the 25FX.
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Re: Magnum 25XLS?

Post by Blue Note »

Keith,

If you look at the break-in instructions for the 15XLS, you will also see the suggested 45 bench running before flying. I have done this on all of mine and they all tune within 200 RPM of each other. That is pretty outstanding for consistency. One problem I have seen with the 15 is that I am over taching more than most other guys...all I can assume is that the break-in procedures vary. We may be faced with a similar RPM dilemma as with the 25 XLS when it comes to Limited B or 2948, but for Open B considerations, I will probably do the bench running. Just my $.02.
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Re: Magnum 25XLS?

Post by David Drowns »

lightning wrote:Does anyone have a spec on the power output? I can't find mention of it in the paperwork. I am curious to compare it to the published .84HP for the 25FX.
Don't know what this one is rated at but the test engine outperformed my Norvell 25 BB with a power rating of 1.1 Hp.

And I don't blame you on expecting it to fly rich. Just today I was wondering what the breakin recomendations were. Not sure if I'd have that much patience.

Mine is at Hobby People waiting for me to pick it up Friday.

Waiting for your review.
patience...patience...
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Re: Magnum 25XLS?

Post by lightning »

Hi David, the break-in instructions say to run it rich for 10 mins, then let it cool for 10 more. Run again for 10 mins leaned out a little, but still rich.
I see no reason those 10 minute intervals can't be in the air. It's not like the engine needs to be leaned out for 10 seconds, then richened again - it's a consistent ten minute run.
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Re: Magnum 25XLS?

Post by boiler »

The 10 minute runs are to get it hot and then cool to seat the piston and sleeve. I used to do that with the LA 15 using an APC 6x2 prop for 90 seconds and then cool. Repeat 2 more times and it was ready to go. You can wait 30 minutes before you put her in the air. You won't be late for work. :wink:
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Re: Magnum 25XLS?

Post by lightning »

Bob, the recommended break-in prop is a 9x5. That is not exactly going to let the motor spin up real fast!
I still don't see the difference between 10 mins slightly rich in the air or on the ground.
My issue is my neighbors will get upset if I do it at home and our other club members will get upset if I run 45 mins on the ground at our field.
Unless I can go out there on a real windy day when most of them are too chicken to fly!
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Re: Magnum 25XLS?

Post by Yankee Samurai »

Sorry but there is a difference between in the air and on a test stand. You load the engine when you fly it where you don't on a test stand. Read Dubb Jett's article on breaking in engines on his web site to gain valuable information. As someone who reworks engines all mine are broke-in on a test stand first before being mounted in an aircraft. Just my $0.02.
Randy Shiosaki
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Re: Magnum 25XLS?

Post by mad »

http://georgiacombat.com/ABCEngineBreakIn.htm This is from Lou's Georgia combat site. Has a link to Dubb's site.
Its been the norm down south for a long time
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Re: Magnum 25XLS?

Post by David Drowns »

Good info Michael, Thanks.
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Re: Magnum 25XLS?

Post by lightning »

OK guys, thanks for all the info, but I'm now even more confused. :? :? :?
The Magnum instructions say to run for ten minutes at a time, with a 9x5 prop, and cool for 10 minutes, gradually leaning for each run for a total of 45 mins running time. I figured they knew what they were talking about as they build and warranty the thing!
No peaking, no pinching, no wild rpms for a few seconds - just run for 10 mins at a time.
THAT is why I figured 10 mins in the air is not much different.
25FXs - I have maybe run one tank on the ground, then flown them rich. I don't have a bad one out of 20.
I was figuring I would do the same with the Magnum.
Randy's comments about LOADING in the air also puzzle me - seems to me there have been many discussions about how much engines UNLOAD once air-borne, so I figured it would not be working as hard as on a test stand. In fact the Magnum instructions specifically state we should expect an rpm increase of between 10% and 30% in the air. Doesn't sound like "working harder" to me!

Now I'm not sure WHAT to do!

Unfortunately the backyard/flying field noise comments are still valid.
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Re: Magnum 25XLS?

Post by Yankee Samurai »

Pitch the nose up you load the engine as it works harder to go up hill (like when you run up hill). Pitch the nose down and the engine unloads ( run down hill not as hard ). Lou's article is a good one to follow.
Randy Shiosaki
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Re: Magnum 25XLS?

Post by mad »

Keith,
There are multiple ways to break in an engine. for our use we want max RPMs. the short prop, very high rpm for a short time method will give you a motor that will turn up higher than one broke in the manufactures way. Remember it is not important to heat the entire engine just the piston and sleeve so it does not need to run a long time. I have an old 5x2 I have used for break-in on 25s and 15s for a long time
Michael DeWoody
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