Oil & Fuel Anyone else had a backwords running diesel motor

[Lawnjocky]

I used to own a Jacobsen mower that had a 21hp Kobota engine. I started it and the motor sounded weird. When I pushed the pedal to go forward the machine went backwards instead. After shutting it off and restarting, it ran fine and never did it again. I was just wondering if this has ever happened to anyone else? Also I have forgotten what it's called when this takes place and why.
Lawn

 

[boomer4snow]

When I was in the service we had to push start an OLD duece and a half with a big ol 5 ton. Popped the clutch on her and it fired. sounded weird and black smoke rolled out the intake. Put it in gear and it shot straight back. Shut it down and refired it after another down hill pop the clutch run, and it was fine.

 

[BigAl]

Yea it can and does happen . It is great for getting rid of Mosquitos from all the black smoke it spews out . /forums/images/graemlins/grin.gif Usally it involves the timing pump from being out of time a little bit .
Allen

 

[skent]

It happened to me once on a Yamaha 360 dirt bike with a 2 stroke engine. When I kicked down on the starter pedal, it kicked back (as it often did) but started. Sounded ok thou. Popped it in first and started to let the clutch out and it went backwards - two on-lookers were amaized that I had a mo-cycle with reverse. I shut the engine down and restarted and it was ok.

 

[AntrimMan]

I saw that happen to the same model Yamaha. The operator did just what you said, kicked, revved and popped the clutch and scared the heck out of both of us. This happened on a paved road with me standing alongside. Weird stuff.

All the best,
Martin

 

[bczoom]

My dad got his to run backwards once but what was unique is that the tractor was running forward at the time.

He was using a Farmi logging winch off the back and trying to drag a log out. He was standing to the side of the tractor pulling on the rope that runs the winch (and looking at the log). Something didn't sound right all of a sudden so he looked behind him at the tractor. The front end was about 4' off the ground. /forums/images/graemlins/shocked.gif Before he could do anything, the engine stopped running forward and started running backwards. He shut it off and restarted with no problems.

 

[MRHURT]

semis can have the same problem, usually happens when trying to pull off up steep hills and you stall it and roll back with the clutch out. we used to cut it off and try the hill again. lots of fun with 9 gears for reverse.

 

[Jagmandave]

I worked on Import cars a lifetime ago, and we had a 2 stoke SAAB come in on the hook one day, same problem, engine running backwards. All it took was a new set of points and setting the timing correctly (before TDC instead of after) and it ran fine. It was interesting have 1 really low forward gear and 4 in reverse...........

 

[roccon31]

its a pretty neat thing to see, but just remember one thing. if it has a pressurized oil system (most modern 4 stroke engines), it has NO oil pressure while running backwards. if not for that, you could run them forever like that.

you will also lose your oil pump prime, and depending on the engine, this can be a big pain-in-the-butt when you restart it.

i saw an ol' Mack dump truck doing it one day at the shop i used to work at. it was interesting to say the least!

 

[TractorLegend]

I believe its all in the timing as others have said. Too early of ignition on the power stroke in the 4 stroke cycle can send pistions careening in reverse.
On a diesel I could see where early injection on the power cycle could do the same.