coil problems....it blew up

[romantic comedy]

Today I was checking spark and poof the coil blew up.

It was filled with oil so there is this light oil all over.
you can see the thicker primary windings
then there is the secondary coil of very fine wire
the this metal pieces were the core in the center

I attached the picture so I am assuming this will appear below it...

Anyway in case you dont know, I cut a coil in half. I have wanted to do it for 40 years. Today was the day. As I was sawing the oil was lubricating the hack saw...

[Al Schober]

Well, I'm glad you got THAT out of your system! Did you figure out why it failed? I take it you didn't reassemble..

Years ago, I worked a while for Rootes Motors in Coventry, UK. The factory had a garage attached for locals to bring their vehicles. A couple of vehicles had shown up with failed manual transmissions - the big nut on the input shaft to the clutch had come loose, letting the main bearing come loose. They sent me down to the transmission line to see what I could see. I found the proper station and watched the woman install the bearing - she put it in place on the shaft, then seated it with a hydraulic press. Then she took the nut, placed it over the shaft, and seated it with the press. Assembly moved on..
I asked to look in her tool cabinet and found a torque wrench - she didn't know what is was. My report? Management failed to properly train her in her job. I was rather amazed they hadn't had more failures than they did!

[romantic comedy]

Al, it was just an old coil I had hanging around. Dont know where I got it. I just felt like checking it out.

[Mo]

Yeah, looks like condensation got to it.... corrosion developed and viola. I know a keener like yourself had another one right there. Boy, I wish I was in Fl now and could go for a sail.

Our docks won't go in until early May this year so I'll put Odyssey in the same day. The boat is ready though. I did the ablative bottom paint last fall, and she just needs her electronics, sails, food, water and rum to go...about 3 hours work tops.

Fired my engine up yesterday on the hard in 28 F. I fire it up once a month now and let it run for about 30 seconds. I giver her a 10 second or so spin on the starter without the choke pulled to get some oil up around then pull the choke...she fired right up. Rick Jones, one of our members was standing around and said "prop is turning". My reply was "she's just itching to get back in the water".

Was asked by a club member about the A4 on Friday night. He's looking at a boat, moving up from a J24 and I've done work on that particular boat. Price is right, I know the engine is good, so alleviated him of the rumors of the A4 being deal breaker. I told him allot will overlook that boat and it would be gone if it had a diesel...so make the arrangements and buy it.

[joe_db]

Yeah, looks like condensation got to it.... corrosion developed and viola. I know a keener like yourself had another one right there. Boy, I wish I was in Fl now and could go for a sail.

Our docks won't go in until early May this year so I'll put Odyssey in the same day. The boat is ready though. I did the ablative bottom paint last fall, and she just needs her electronics, sails, food, water and rum to go...about 3 hours work tops.

Fired my engine up yesterday on the hard in 28 F. I fire it up once a month now and let it run for about 30 seconds. I giver her a 10 second or so spin on the starter without the choke pulled to get some oil up around then pull the choke...she fired right up. Rick Jones, one of our members was standing around and said "prop is turning". My reply was "she's just itching to get back in the water".

Was asked by a club member about the A4 on Friday night. He's looking at a boat, moving up from a J24 and I've done work on that particular boat. Price is right, I know the engine is good, so alleviated him of the rumors of the A4 being deal breaker. I told him allot will overlook that boat and it would be gone if it had a diesel...so make the arrangements and buy it.

Running the engine but not long enough to heat up the oil is not a good thing IMHO.
Speaking of itching, this weekend would have been a perfect but family stuff is going on Perfect sailing weekend - dang!

[Mo]

Every engine started in the cold goes through the same 30 seconds whether it heats up or not. 28 isn't cold, -40 is cold. My engine runs less than 5 minutes from start to shut down every time I come of the dock...idling to warm up is a myth and actually worse on engines. I own a truck with a 3306 Cat diesel engine in it and I don't let it idle. I'll shut it down if I'm sitting and fire it up again when ready to go. I know there's different views but the Society of Engineers say fire up an engine, idle 30 seconds and go. Older engines and idling...this practice became more of a tradition of the years. It wasn't because of the engines, it was because of batteries...back in the day battery quality were not great and certainly not what they are today. So people had to start the engine and allow them to charge the battery in case they stalled it out...they wouldn't be able to restart....and of course there were the old dodge engines...CHOKES, anyone remember them. If you didn't let it warm up for 10 minutes the automatic choke would stall it out in the cold anyway...my Dad had dodges and I didn't like their cold weather starts.

Beautiful here today for sailing as well. It was 52 F here today. Unfortunately, I ended up washing 3 cars, mats and carpets where salt was tracked into them. A spring day here today...but we always get a wicked snow in March, never fails.

EDIT: After thought: I did miss the biggest reason people idle their cars these days. In my dads day had to sit in the Chrysler and keep it running as those choke were just murder to set up. Those chokes were notoriously junk...I'd be the boy who had to dress up and sit in it at -30 to keep it running. If I let it die I better not let her die the second time or she'd need a boost the third. Today's fuel injection has ended all of that. The main reason engines idle after startup today is comfort, convenience and safety. My wife idles the Subaru every morning she's headed to work...she starts it 10 minutes before she leaves. It lets the car warm up, heated seats warm the seats, windsheild clears , defrost the rear etc... it's not about the engine even though that thing bangs like a diesel on a good day...boxer engine.

[sastanley]

....and of course there were the old dodge engines...CHOKES, anyone remember them. If you didn't let it warm up for 10 minutes the automatic choke would stall it out in the cold anyway...my Dad had dodges and I didn't like their cold weather starts.

Mo, My first car, a 1978 Civic, had a manual choke just like my A-4 does.

We had terrible auto chokes in some GM vehicles when I was little..my old man was always fiddling with them.

[joe_db]

Every engine started in the cold goes through the same 30 seconds whether it heats up or not. 28 isn't cold, -40 is cold. My engine runs less than 5 minutes from start to shut down every time I come of the dock...idling to warm up is a myth and actually worse on engines. I own a truck with a 3306 Cat diesel engine in it and I don't let it idle. I'll shut it down if I'm sitting and fire it up again when ready to go. I know there's different views but the Society of Engineers say fire up an engine, idle 30 seconds and go. Older engines and idling...this practice became more of a tradition of the years. It wasn't because of the engines, it was because of batteries...back in the day battery quality were not great and certainly not what they are today. So people had to start the engine and allow them to charge the battery in case they stalled it out...they wouldn't be able to restart....and of course there were the old dodge engines...CHOKES, anyone remember them. If you didn't let it warm up for 10 minutes the automatic choke would stall it out in the cold anyway...my Dad had dodges and I didn't like their cold weather starts.

Beautiful here today for sailing as well. It was 52 F here today. Unfortunately, I ended up washing 3 cars, mats and carpets where salt was tracked into them. A spring day here today...but we always get a wicked snow in March, never fails.

EDIT: After thought: I did miss the biggest reason people idle their cars these days. In my dads day had to sit in the Chrysler and keep it running as those choke were just murder to set up. Those chokes were notoriously junk...I'd be the boy who had to dress up and sit in it at -30 to keep it running. If I let it die I better not let her die the second time or she'd need a boost the third. Today's fuel injection has ended all of that. The main reason engines idle after startup today is comfort, convenience and safety. My wife idles the Subaru every morning she's headed to work...she starts it 10 minutes before she leaves. It lets the car warm up, heated seats warm the seats, windsheild clears , defrost the rear etc... it's not about the engine even though that thing bangs like a diesel on a good day...boxer engine.

Totally different issue but not always applicable to old engines.
1: My point is that unless you run the engine long enough to warm the oil, all you are doing is adding contaminants and water to the oil. If you are going to run the engine, it should be allowed to heat up. Running engines just briefly to get on and off a mooring is really tough on them, they need to get run hard for 30 minutes or more every now and then.

2: Warming them up before use is another issue. Modern cars with synthetic thin oil hardly need to be warmed up unless the car is so cold-soaked the transmission won't shift. Old boats and airplanes are another matter. Many airplanes have an oil pressure gauge with a green arc and there is too low and too high. In cold weather you should let the engine run a bit at idle until the oil pressure comes down off the peg and into the green arc. Among all the other reasons it is bad to fly off with thick cold oil is the engine oil also controls the prop pitch and if it is too thick, the prop governor can fail to function. My A4 will peg the oil pressure gauge when started on a cold day. I always let it run at idle until the gauge moves down to 60 or so before moving out of the slip. if I start the engine first thing it usually has done so by the time I get the shore power cord put away and start releasing lines.