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Author Topic: Yes, my twin ran backwards today! What fun  (Read 7211 times)

cujet

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Yes, my twin ran backwards today! What fun
« on: August 10, 2013, 10:37:20 PM »
 :)

I've been getting weaker rather rapidly as I age (I'm 49)(some health issues) . I'm not exactly able to crank over my 20HP twin with enough speed to get it to start lately. But, feeling good today, I thought I'd give it a try. Two hands on the handle, crank it as fast as I can (not enuf) and release the compression. It stops and kicks back, with enough force to get it to rotate backwards with lots of speed. The engine then starts on one cylinder and belches the nastiest smoke you have ever seen, out of the air filter!!! It comes up to speed and the generator comes on line!

Handle still attached to the crank, firmly, as the drive pawl is fully engaged in the direction of operation. I'm smart enough to get away from this. So, I sit there and watch it run for a bit. Sounds nasty, smells nasty. I'm sure my neighbors love me now, with huge clouds of acrid black smoke going up.

Finally, I take stock of the situation (fuel rack was full open) and go around the other side. Reach over and shut off the fuel lever. It comes to a halt.

Now, I was under the mistaken impression that 4 stroke diesels could not operate backwards, as the series of intake-compression-combustion-exhaust must be in that order. But, it seems that I now have a Bi-Directional Listeroid.

Guess I'm getting an electric starter. I can no longer start this thing!

I'll check the injection timing and probably degree the camshaft again. Along with a careful inspection the internals for a broken timing gearset or something. I suspect nothing is wrong and I'm just weak.
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bandmiller2

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Re: Yes, my twin ran backwards today! What fun
« Reply #1 on: August 11, 2013, 02:24:10 AM »
I would say your roid goes boath ways.I used to get panicked calls from the firefighters when a Detroit diesel was running backwards.I didn't think they would run long that way but if you have  compression and injection somethings going to happen.Many of the old marine diesels such as the Enterprise were direct coupled to the props and had to be shut down and the camshaft shifted slightly and restarted to back up.
Fast cheap and easy are seductive sirens,its a rare man that does not court their pleasures.

cujet

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Re: Yes, my twin ran backwards today! What fun
« Reply #2 on: August 11, 2013, 01:59:32 PM »
I have the original oil bath air filter. However, I don't have oil in it right now. So it did not blow oil out of the unit, thank goodness.

Any thoughts on the best electric starter for a 20/2 with the big flywheels?
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mike90045

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Re: Yes, my twin ran backwards today! What fun
« Reply #3 on: August 11, 2013, 02:32:02 PM »
Any thoughts on the best electric starter for a 20/2 with the big flywheels?

Will you decompress it, or try cranking through compression?

listard-jp2

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Re: Yes, my twin ran backwards today! What fun
« Reply #4 on: August 11, 2013, 03:39:57 PM »
In the UK, early Fordon diesel Major tractors were well known for this to happen. It was usual for the engine to start in reverse when the engine became stalled under high load.
Due to having a gear type oil pump, you could easily wreck the engine if you could'nt stop it quick enough (as the bearing surfaces were starved of oil when the engine was running in reverse).
Simms the manufacturer of the fuel injection system, modified the fuel injection pump injection characteristics on later Super major and Power major tractors to eliminate this tendancy.

selmawp

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Re: Yes, my twin ran backwards today! What fun
« Reply #5 on: August 11, 2013, 10:25:13 PM »
http://www.youtube.com/watch?v=E2-R_8dRPUo
Hi, check this video simple and affective, I have 2 left.

overbore

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Re: Yes, my twin ran backwards today! What fun
« Reply #6 on: August 16, 2013, 03:34:08 PM »
Great product; highly recommend seller and unit--- 5 Stars--
Laus Deo
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Horsepoor

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Re: Yes, my twin ran backwards today! What fun
« Reply #7 on: August 17, 2013, 08:09:30 AM »
Chris, buy the starter in the video. You cant beat the price and you dont have to build your own.
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overbore

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Re: Yes, my twin ran backwards today! What fun
« Reply #8 on: August 19, 2013, 06:16:34 PM »
I have the original oil bath air filter. However, I don't have oil in it right now. So it did not blow oil out of the unit, thank goodness.

Any thoughts on the best electric starter for a 20/2 with the big flywheels?

If you purchase the great starter from Tony, I can help you ( remotely) mount it as it is easy to do.
Laus Deo
overbore