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Broken plane in St George, UT: help advice welcome

erikpmort

erikpmort

Well Known Member
Well, bummer. First big xc and I'm stuck at the moment. Flew down to st George from Logan on Thursday, came back today and the plane wouldn't start up. Tried to avoid over cranking and I did let it sit for a while incase it was flooded. No luck. Also tried to clear it with full lean half/full throttle etc. no luck.

Pulled cowls and checked plugs. Figured on a Newley overhauled motor it's gotta be something simple. Found a little oil in left lower plugs but none on the right side. Cleaned em and still nothing.

The thing is it never sputtered once. I felt like it was ignition related. Called my A&P and he said to take one of the top plugs out, reconnect the top and crank it to see if you can see spark. I didn't see any. I'm stuck at this point. I know very little and can't get an A&P out here to look at it until tomorrow.

Any advice welcome.
 
If there is no spark from either mag, look at what is common to both mags. If you have a keyed ignition, perhaps it's keeping the mags grounded. Try disconnecting the wire labelled GND on the back of the keyswitch, if you have one.

Bevan
 
Or just remove the "P" leads from the mags, if this works fly it home and check it out in the comfort of your own hanger.
 
Erik,

The P leads are the wires that ground out your mags until you switch them on at start. If there is an issue in your wiring you can bypass all of it by just removing the P-leads from your mags. Keep in mind you now have two hot mags all the time!! So when you get home make sure you re-connect the P leads. These two wires are pretty obvious on the side of your mags, just remove the screws and let the wires loose. Good luck!
 
erikpmort said:
Thanks!

What does the p lead do ? And how will it work without them
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If you don't understand how P-leads work please do not work on your engine unassisted. You are dealing with a potentially deadly situation. Hopefully you can find an A&P or experienced RVer who can help you get your plane home.
 
THIS!!!!!

Sam Buchanan said:
If you don't understand how P-leads work please do not work on your engine unassisted. You are dealing with a potentially deadly situation. Hopefully you can find an A&P or experienced RVer who can help you get your plane home.
Click to expand...

PLEASE!!!!
 
You should only disconnect the impulse mag, usually on the left. It has the spacer between it and the case. The other should only be disconnected AFTER the motor is running.
 
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gasman said:
You should only disconnect the impulse mag, usually on the left. It has the spacer between it and the case. The other should only be disconnected AFTER the motor is running.
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Explanation; If you disconnect the "non-impulse" mag, it will fire early during starting and could damage the starter.
 
The RV-6 I fly now would't start worth a **** when cold, but when it was warm it started no problem. Turned out to be reversed p-leads to the mag switch which disabled the wrong mag (the mag with an impulse coupling.)
 
Thanks guys. I wasn't working on it alone, I just wanted to have some good ideas to go from when I got started with the A&P in the morning. He told me the left mag is bad,(the one with impulse) so I'm sending it in to get overhauled. Lucky the A&P that sold me the plane offered to fix it for free minus parts. I'm sending it to him. Thanks for everyone's help.

It is a slick model 4272

Serial 90050012

Kinda makes me want to get electronic ignition.
 
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erikpmort said:
Thanks guys. I wasn't working on it alone, I just wanted to have some good ideas to go from when I got started with the A&P in the morning. He told me the left mag is bad,(the one with impulse) so I'm sending it in to get overhauled.

Kinda makes me want to get electronic ignition.
Click to expand...

Check out Robert Paisley at EFII. Great electronic ignition and great to work with!
 
erikpmort said:
Thanks guys. I wasn't working on it alone, I just wanted to have some good ideas to go from when I got started with the A&P in the morning. He told me the left mag is bad, so I'm sending it in to get overhauled. Lucky the A&P that sold me the plane offered to fix it for free minus parts. I'm sending it to him. Thanks for everyone's help.

It is a slick model 4272

Serial 90050012

Kinda makes me want to get electronic ignition.
Click to expand...

Or you could just replace the other (non-impulse) mag with electronic ignition, especially since you'll be getting a new/overhauled impulse mag back. That way you get most of the benefits of E.I. with the least amount of capital outlay! And you'll have two sources of starting ignition. :)

Glad to hear your almost fixed, safe flight home.
 
results

so the Fbo diagnosed it as a bad mag. they told me its hard to find people to work on them and that i may not be able to find anyone to overhaul it. Well come to find out these guys don't know their stuff because the other 2 A&Ps i know were willing to look at it, and guess what? it ended up only needing the contact points cleaned! my local A&P said its unusual for something like that to be the problem, but he also checked the condenser and everything else looked fine.

Anyway, frusterating :mad: that the FBO there wasn't even willing to open up the mag. the guy i sent it to had it working in 15 minutes. I could have flown home the same day. Glad it wasn't worse, but gee sometimes its hard to find good help....

I like the idea of one mag and one EI. i may do that at somepoint. thanks for the advice. Now i gotta go fetch my plane 500 miles away
 
erikpmort said:
so the Fbo diagnosed it as a bad mag. they told me its hard to find people to work on them and that i may not be able to find anyone to overhaul it. Well come to find out these guys don't know their stuff because the other 2 A&Ps i know were willing to look at it, and guess what? it ended up only needing the contact points cleaned! my local A&P said its unusual for something like that to be the problem, but he also checked the condenser and everything else looked fine.

Anyway, frusterating :mad: that the FBO there wasn't even willing to open up the mag. the guy i sent it to had it working in 15 minutes. I could have flown home the same day. Glad it wasn't worse, but gee sometimes its hard to find good help....

I like the idea of one mag and one EI. i may do that at somepoint. thanks for the advice. Now i gotta go fetch my plane 500 miles away
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I like that idea too, but currently I have two impulse mags, both are hot at start, it you had this you would have started the engine and the dirty points would have cleared by the time you got to the run-up area and you would be home, also very handy in the back country where you need it to start and work every time, at least on one mag.
 
erikpmort said:
Good point. Can I add an impulse coupler or whatever you call it to my existing R mag ?
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I cant say for sure but I don't think you can, I think you would need a new impulse mag and the gear and the spacer, I think they sell them in a kit. If I had to do that I would just get EI on the non impulse side.
 
Russ McCutcheon said:
I cant say for sure but I don't think you can, I think you would need a new impulse mag and the gear and the spacer, I think they sell them in a kit. If I had to do that I would just get EI on the non impulse side.
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And maybe the hardest part would be replacing the studs in the case to fit the impulse mag.....
 
I have a question. If I replace the right non impulse mag with a e-mag model P, what is the relationship between the electronic ignition and my existing mag ? Do I only get 50% of the EI benefits because I don't have both sides ?

So I'm stuck on a broken plane to go get my broken plane today. (Skywest) fun stuff !!
 
erikpmort said:
I have a question. If I replace the right non impulse mag with a e-mag model P, what is the relationship between the electronic ignition and my existing mag ? Do I only get 50% of the EI benefits because I don't have both sides ?

So I'm stuck on a broken plane to go get my broken plane today. (Skywest) fun stuff !!
Click to expand...

I'm not a P-mag expert, but basically what you'll have are two ignition sources that will fire at TDC for start, both will fire at 25° BTDC at takeoff, and the P-mag will advance the timing up to some maximum (on mine it's 42° BTDC) depending on manifold pressure and RPM. So at high altitude you'll get a more efficient and more complete burn. The mag, of course will still be firing at 25° BTDC, but it adds something to the burn such that if you turned it off at high altitude you would probably notice it. I think you would get most of the benefit of having two E.I.'s, I've heard 90%, but 80% sounds reasonable too. Also, with the P-mag, it should be a fairly easy install since you won't have to change studs; you might want to convert to auto plugs for the P-mag, which will require the inserts for the plug holes. But that is strictly your choice, aviation plugs will work too, but you'll have to re-gap them.
 
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I have an O-320, first I had two mags, then one each, then two P-Mags. With one each, I got all (as far as I can tell) of the benefits of quick starting, better idle, and saved 1 gph in fuel burn. With two P-Mags, I get perhaps a little better idle (I idle at 400 rpm and it is very smooth) and I gained 4 mph top speed, and a little higher cruise at any setting. I gained very little in fuel burn with the second P-Mag, maybe .2 gph. The first one is the biggest deal, performance wise. YMMV.

Bob
 
Perfect thanks ! Got my plane home today, and even had nice tailwinds. 175 kts most of the way woo hoo. Looking forward to the upgrade. Gotta pay my darn sales tax first :(
 
erikpmort said:
What could my right side non impulse slick mag sell for ?
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How much time on it? Model number? I would look up the new price and figure about 50% for a quick sale, depending on time, of course. I think the current model number would be 4370 for the non-impulse, seems like you might have an earlier model #.

Keep in mind that these are 500 hour mags and used to be called "throwaway mags." However, they can be overhauled for a couple hundred bucks.
 
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Pat Hatch said:
Keep in mind that these are 500 hour mags and used to be called "throwaway mags." However, they can be overhauled for a couple hundred bucks.
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People keep saying this and it’s not accurate, these require a 500 hour inspection, they do not need to be replaced or O/H at 500 hours, I have one with about 700 hours, I replaced the points for $50 last year, otherwise it was and is in good condition and running well.

Still 50% price of new at most.
 
Slicks can be rebuilt just fine

I've had two Slicks rebuilt at Magneto ER in Searcy Arkansas. He was very reasonable and super fast turnaround. Their phone number is (501) 724-2225

The slicks worked OK on the O-235... but the 200HP IO-360 loves those big old Bendix mags.
 
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