interesting...

Y

ysr89

Member

Dec 4, 2007

108

0

• Mar 30, 2008

• #1

Funny thing happened today, I took my 87 CR125 out for a quick test run (Just got it running, it ran and idled very good.) All was well, was riding for about 10 minutes when all of a sudden something very interesting happened. I stopped for a few seconds, and when I went to start again, I was going backwards! I guess something must have happened to start the crank turning in the opposite direction, but I didn't notice any misfiring. It ran perfectly fine backwards, but I shut it off because I don't know if it could harm the motor. Does anyone know how to fix this? I haven't tried anything yet, but I was thinking of taking off the flywheel cover and just turning it in the right direction. Has this happened to anyone else here?

 

A

atkkid250

Uhhh...

Mar 18, 2008

177

0

• Mar 30, 2008

• #2

wow

lol, never heard of this but ive thought about it, i have no idea how it happens or why but it sounds strange, will it go fast back wards, like 5th gear back words? lol, get good at riding back words and make a world record. sorry.

 

XRpredator

AssClown SuperPowers

Damn Yankees

Aug 2, 2000

13,504

19

• Mar 30, 2008

• #3

I've never had it happen with a motorcycle engine, but I did have a 6V92 Detroit "Screamin' Jimmy" Diesel 2-stroke run backwards once. I shut it down quickly before any damage could happen.

The reason it happened to me was that I'd dynamited the brakes and my foot slipped off the clutch, making the engine kind of "bounce off" the brakes and end up going backwards. I would imagine it would take the same kind of "bounce" to make a motorcycle engine run backwards as well . . .

curious

 

Y

ysr89

Member

Dec 4, 2007

108

0

• Mar 30, 2008

• Thread starter
• #4

I'm not sure how it happened, I've heard it could be off ignition timing, but it ran awesome backwards. I got it going normal again, and it cooks. It runs perfectly. All I did was take off the flywheel cover and turn it in the right direction a few times by hand. Definately a memorable ride! Maybe this thread could become the "How do motorcycle engines run backwards" thread. The only thing I can think is somehow the crank started turing the opposite way, reversing the primary drive gear, clutch and tranny. But I didn't feel or hear any misfiring. Just riding, stopped, and suddenly riding backwards. Maybe Rich knows?

 

Shaw520

Damn Yankees

LIFETIME SPONSOR

May 14, 2000

1,082

6

• Mar 30, 2008

• #5

The old Ossa's and Bultacos were noted for this, most common when starting, the compression stroke would cause a kickback and the engine would start in reverse.
I havnt heard of this happening to newer bikes.

 

F

fatboyslim

Member

Apr 11, 2006

255

0

• Mar 31, 2008

• #6

Check the timing mark and woodruff key to see if the mark is lined up and if the woodruff key is sheared off.

 

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adamchatum

Member

Jun 17, 2007

7

0

• Apr 1, 2008

• #7

Ski-doo's and polaris's snowmobiles run their engines in reverse, to reverse! Also check out this guy on youtube on his IT175 engine in reverse http://www.youtube.com/watch?v=0ZbgUPvcW1s

 

Y

ysr89

Member

Dec 4, 2007

108

0

• Apr 2, 2008

• Thread starter
• #8

The IT video was neat! It's running normal now, but I'm having some issues with it. It runs, revs and idles perfectly, but feels like its struggling to pick up speed when its moving.

 

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BigRedAF

Member

Jan 9, 2005

739

0

• Apr 2, 2008

• #9

I had a Hodaka that would run backwards half the time. I used to let my drunk friends try and ride it, quite a laugh.

The cause is your timing is advanced to far, check that your marks are lined up. Modern bikes shouldn't have this issue.

 

oldguy

Always Broken

Dec 26, 1999

9,411

0

• Apr 2, 2008

• #10

Not really all that unusual about once a month we get this same post
http://www.dirtrider.net/forums3/showthread.php?t=161875

 

Y

ysr89

Member

Dec 4, 2007

108

0

• Apr 2, 2008

• Thread starter
• #11

Yeah, I searched after posting, I did things a little out of order! I still think it's interesting that it happened, and pretty funny! Surprised the Hell out of me, that's for sure!

 

U

Uchytil

LIFETIME SPONSOR

Jun 29, 2003

814

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• Apr 2, 2008

• #12

FYI, 2 cycle 1 cylinder engines can easily run backwards. The yamaha golfcarts run in both directions by means of the cranking motor being reversed thus eliminating the need for a reverse gear as in 4 cycle carts. Some of the big (old) ships I worked on also ran their engines in reverse by rotating them backwards with DC motors, again 2 cycle.

 

Y

ysr89

Member

Dec 4, 2007

108

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• Apr 2, 2008

• Thread starter
• #13

So it's not bad for it to run backwards?

 

Shaw520

Damn Yankees

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May 14, 2000

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• Apr 2, 2008

• #14

So,.. once they start putting all the r&d into getting them to run backwards,...... could you imagine how fast they would be forward!

 

J

_JOE_

~SPONSOR~

May 10, 2007

4,697

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• Apr 3, 2008

• #15

It's definately worse for the rider than the bike, lol.

 

Y

ysr89

Member

Dec 4, 2007

108

0

• Apr 3, 2008

• Thread starter
• #16

Shaw520 said:

So,.. once they start putting all the r&d into getting them to run backwards,...... could you imagine how fast they would be forward!

Click to expand...

One can only imagine...