N252MK

Starting problem

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I have a starting issue that began a few times before having the starter replaced and has continued since. This is a 1997 Bravo. The engine turns over when pushing in the key in starter position but doesn’t fire until I release and turn the key towards the off position. I’m not exactly sure if it’s firing on pressure release or from when I start to turn it off (which I think it’s when turning towards off position). So far I haven’t tried a hot start this has been with a cold or slightly warmed engine. 

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I don't know a thing about the Bravo engine.  Does it use a shower of sparks or an impulse mag?

Starting when the key is released is a classic symptom.  It's been covered several times before.  Try a Mooneyspace search using Google.

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Here's how it works on many Pipers and Cessnas.  One mag has an impulse coupling to help start the engine.  The other does not, and as it is set at XX before TDC, it is grounded during cranking to prevent firing and kick backs from that mag.  Now if the impulse coupling mag is not working, then when you release the starter 'on' switch, the engine is turning fast enough to start on the other mag, or kickback on the other mag.

Now there are many variations on the above, two impulse coupling mags, shower off sparks etc.

 

Aerodon

 

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The Bravo only has one impulse coupling. It is on the left Magneto. Recently I was having starting problems and it was found that my impulse coupling was only working intermittently. I know of one other Bravo owner that had the same problem with hard starts due to the impulse coupling.

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Also, reversed P-leads can do this. The switch grounds the right mag and allows the left mag wirh the impulse coupler start the engine. When they’re reversed, the impulse mag is grounded and the other mag isn’t spinning fast enough to spark. When you release the key you unground the left mag and it lights off and starts the engine. 

Edited by jetdriven

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My issues with this switch was not of a technical nature, but rather one of frustration.

The mechanics of fiddling,  turning, twisting pushing et. al, ad nauseam just became too much and not at all necessary.

A&P installed a twist to start sw. that is now slick easy and effortless to use,  or as they say in Kentwood,

"Like socks on a rooster".

Just my thoughts. 

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My challenge with the socks on the rooster style...

Its hard to tell which position the key is actually in...

One more click to the left during the run-up... the engine suddenly quits.

One more from both, the starter gets power?

Not bad, if you have a really strong memory of everything you do...

Where is Clint...  did I use five or did I use six?  :)

I'm starting to like the idea of the two switches and a start button routine.

Best regards,

-a-

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On ‎10‎/‎22‎/‎2017 at 7:56 AM, N252MK said:

I have a starting issue that began a few times before having the starter replaced and has continued since. This is a 1997 Bravo. The engine turns over when pushing in the key in starter position but doesn’t fire until I release and turn the key towards the off position. I’m not exactly sure if it’s firing on pressure release or from when I start to turn it off (which I think it’s when turning towards off position). So far I haven’t tried a hot start this has been with a cold or slightly warmed engine. 

I just had this happen to me on my M20F.  I realize it is a different engine but the operation of the mag is similar.  My issue was all the leads were in the correct position and the switch tested good.  What had happened is that one of the "P" leads was not making a good contact inside the magneto.  Apparently this is a common issue and a little bit of silver solder fixes the issue. Might be worth checking.  I spent months tracking down a stupid fix.  My symptoms were IDENTICAL to yours.  Reminded me of an old Ford that the ignition bypass wire was broken and would only start on the key return to accessory position  if you caught the engine in time while it was spinning. 

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