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Whoops, deleted topic Ignition!


FlyingMonkey

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I will repeat my last question here:  Has anybody had a failed "soft start" module, or are all the failures confined to the older modules?  In other words, is replacing modules a "one and done" item, or can we expect to drop $2k to keep the airplane starting every few years?  If that latter, this *significantly* increases the per hour operating cost of a 912-powered airplane.  

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1 minute ago, Tom Baker said:

I had a customers soft start module fail on his flight home from maintenance, but it was no fault of the module.

I don’t understand this statement Tom! ?

It failed but it wasn’t the fault of the module!!

Can you elaborate Thank!

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20 minutes ago, Buckaroo said:

I don’t understand this statement Tom! ?

It failed but it wasn’t the fault of the module!!

Can you elaborate Thank!

I knew that would raise an eyebrow.

Let me first start by saying I did not do the hose change on this airplane.

A piece of hose debris made it to the inlet of one carb blocking the fuel to that carb. Suffice to say that the engine doesn't run smoothly on 2 cylinders. There was also an improperly secured free end on a Band-it clamp. Due to the extreme vibration and the improperly installed Band-it one bundle of leads coming from the module were severed.

After the incident I replaced the 1/4" hose from the fuel pump the divider. I cut the old hose open and there were chunks of the inner hose liner that were loose. I think there was a bad batch of hose back then.

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Well Stanley, you've really done it this time!  Who will admit they're old enough to know where this quote came from??  Ahhh, but I digress.  I sent in a request to Carmo, the module rebuilding company, to send me information on their rebuilding of the Rotax module.  ZZ Top posted Carmo's reply to my request here on this thread.  I have no idea why this reply ended up on the forum instead of in the form of a emailed reply back to my email address.  If ZZ Top is there, I'm wondering if he/she might be the Carmo contact or a person who is associated with Carmo?  If you could please clear this up it would help me keep my contacts straight.  Also, the post by ZZ Top provided information on the cost and timing of Carmo's module repair.

Update:  Andy, I happened to have bookmarked this thread before you deleted it and the following link, at least on my computer, shows the old thread thru page 3. 

I was hoping that it would show ZZ Tops entry but it does not:

http://ctflier.com/topic/4523-912-ignition-modules/

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I just got my replacement modules from Lockwood yesterday evening.  They also make a "Y" cable for enabling the soft start functionality, which I purchased.  The instructions are a bit fuzzy, but it looks like you just pop out the rubber blocks on the unused pin on the pin block connectors, and slot one of the (I think female) pin connectors into each of the blocks, then connect the other end of the "Y" to the starter solenoid.  Seems pretty simple, and it looks like if it fails or you get it wrong somehow you just lose soft start and the modules will still start the engine.

Hopefully I will be back to flying by the weekend.   

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I’ve heard that in flight if you lose one of the electronic ignition modules the other will continue you to a close airport with just a slight rpm loss like you get during mag check. 

Then a person with experience with Rotax said if you lose a ignition during flight the engine will shake so bad you’ll have to land ASAP. He said only half the engine will run.

Which is true?

 Thanks 

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I got my replacement modules installed yesterday.  The hardest part is getting the new soft start wires into the connectors; Rotax only gives you about an inch and a half of wire between the ignition coils and the connectors, so you have to be a contortionist with your fingers to get them inserted.  

Once it was all back together, I reconnected the negative battery terminal and attempted a start.  It fired on the second blade, ran normally.  I might have been able to tell a slight difference on startup with the soft start feature enabled, but it's pretty subtle.  I let the engine get to takeoff temp, then did a 4000rpm runup and did a mag check at 3200rpm.  Everything acted perfectly normal.

I didn't have time to fly yesterday, but I should be able to Sunday if the weather holds.  Everything seems great at this point.  Except my wallet, of course!

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The standard modules started at 4 BTDC and then after the engine hit 850 rpm it switched to 26 BTDC. So the engine was starting on a piston up stroke.

The soft starts modules start at 3 ATDC for 5-6 seconds and then switch to 26 BTDC. Now the engine starts on the downward stroke of the piston and not the up stroke. The engine may feel a tad rough in those first few seconds, but then you should hear it smooth right out and pick up those few extra rpms.

What's unique about the Rotax plug firing is it fires on every stroke of the piston while most 4 strokes only fire on every other stroke. This adds a bit of safety and redundancy. 

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