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Discussion Starter #1
Hey johndeere guys I have a problem with my 1965 round fender. I just did a whole electrical tune up on my round fender even put on a new generator. Went and cut some grass then shut it off, came back 2hrs later put it on the truck took it home. Then I go to star it the other day and I noticed that it was spitting out the gas air mixture out the front of the carburetor. Without that was kinda weird then noticed that the motor is turning over clockwise instead of counterclockwise. What did I do wrong. I did check the valve clearance a few days prior. Any Imput would be appreciated thanks gents!
 

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That is odd, especially since it ran OK for a cutting and transport home. Can you pull the starter and check its rotation? If that is OK, it has to be something else, perhaps a stuck intake valve allowing mixture to blow back through the carb. Having said that, it would seem like it would back fire instead of raw mix coming back. Dunno...

Seems like an odd problem, but I'd begin with the starter, move on from there. Wish I had some better info for you. If you figure it out, please post your findings.
 

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I did that with a briggs and stratton motor on a tractor ,,had the battery hooked up backwards:tango_face_sad:
 

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I did that with a briggs and stratton motor on a tractor ,,had the battery hooked up backwards:tango_face_sad:
Right: If a battery is hooked up backwards and the starter is a Permanent magnet type starter it will crank backwards. Sometimes this will smoke the charging system, sometimes just blow a fuse, sometimes tha tcharging system will still be ok. Keep your fingers crossed if you hooked the battery backwards.

A automotive type battery usually won't spin backwards even is bat is reversed because the field winding and arm winding are in series.

AND it's quite common to see gas spitting back up through a carb throat on a engine that has compression relief on the intake valve

AND we do not know what engine you have???? but most generally small engines crank Clockwise like you say yours is cranking when looking at the flywheel.
 

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Though it may be possible to get a permanent magnet starter to spin "backwards" by reversing the polarity of the battery cables,if it has a bendix drive,the spiral will not let the drive gear pop up and engage the flywheel,nor would the starter drive's clutch engage..

A starter/generator might be able to spin backwards though,and since they use a v-belt to turn the engine over,I guess it could happen on one of those..
 

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Though it may be possible to get a permanent magnet starter to spin "backwards" by reversing the polarity of the battery cables,if it has a bendix drive,the spiral will not let the drive gear pop up and engage the flywheel,nor would the starter drive's clutch engage..

A starter/generator might be able to spin backwards though,and since they use a v-belt to turn the engine over,I guess it could happen on one of those..
Thanks for the correction. I forgot that even though the permanent magnet type small engine starter motor will spin backwards the Bendix drive spiral would not even engauge as you say. :tango_face_wink:

The OP has not come back yet. I suspect he might have been confused and his engine was actually cranking in the proper direction and the gas spitting up out of the carb throat confused him. (since he said it is cranking CW looking at the flywheel)
I've seen several small engines that gas will spit out the carb throat when cranking due to compression relief on the intake valve. All the gas will go the proper direction when the engine start running and turning faster.
 

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Sitting here trying to figure out how a 4 cycle engine could possibly run backwards.
If someone figures out how to make on burn air only. Thats so toxic. air.
 

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There are reverse rotation 4 stroke engines--but they only run "backwards",they cannot run in either direction...Marine inboard engines often have two V8 engines ,and one is set up with a different camshaft and distributor gear in order to run in the opposite direction of a "normal" one used in a vehicle..A friend had a big boat with two 318 Mopar V8's set up that way..I forget if the starter was a special unit so it would crank "backwards" ,I would think so..

I wonder if anyone ever put one of those marine engines in a car and ended up with three speeds in reverse and only one forward ?...

Some golf carts have 2 cycle engines that will run in either direction,and they have a starter/generator that can spin the engine in either direction ,so they do not need to have a reverse gear,they simple start & run the engine backwards to back up!..

I once had a 2 stroke dirt bike stall out while climbing a steep hill in a sand pit--it started rolling backwards,and the engine started up running backwards,and acted like it was stuck wide open..!..it was a very scary and fast trip to the bottom of the sand pit,and the cycle did a backwards flip when it hit bottom,was lucky I wasn't crushed under it,it flew right over me and landed about ten feet away..
 

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Sitting here trying to figure out how a 4 cycle engine could possibly run backwards.
If someone figures out how to make on burn air only. Thats so toxic. air.
If we did that, we'd burn too much oxygen out of the atmosphere and finally there wouldn't be enough to make the plugs fire.
 

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Discussion Starter #11
Hey guys I have figured out my problem. The problem was that I got a generator off of a cub cadet put that on kinda figured **** is a Kohler so it should be the same. Well it wasn't. I thought the John deere generator was bad but turns out I had a bad ground when I went to field test it. So now I made a rookie mistake that I have learned from now it starts and I can now cut my grass!
 

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Cub starter/generators turn opposite direction of all other starter/ generators . The cub starter /generators are hooked to the drive shaft side of engine . All other starter generators are hooked the the flywheel side of engine. I found out about that when putting a spare deere starter/generator on a cub and it turned the wrong way.

As I stated earlier ,I also had a briggs and stratton starter turn the wrong way, when hooking up the battery backwards ,,that was a different tractor
 

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There are reverse rotation 4 stroke engines--but they only run "backwards",they cannot run in either direction...Marine inboard engines often have two V8 engines ,and one is set up with a different camshaft and distributor gear in order to run in the opposite direction of a "normal" one used in a vehicle..A friend had a big boat with two 318 Mopar V8's set up that way..I forget if the starter was a special unit so it would crank "backwards" ,I would think so..

I wonder if anyone ever put one of those marine engines in a car and ended up with three speeds in reverse and only one forward ?...
Probably, but it wouldn't last long if the accessories were changed to the automotive variety. The water pump, power steering pump, and alternator would also be turning backwards.

Old school marine engines, like old school automotive engines, could be reversed on the fly. Spark timing was controlled by a manually operated lever that could be thrown over for reversing the engine. The engine did have to be idled down to low rpm to be successfully reversed without actually stopping and restarting. Those old engines were started by manually spinning the flywheel (marine and industrial), or turning a crank at the front of the car.

Modern marine diesels for cargo ships are also reversible. The weight of a reversing gear box that can handle many thousands of horsepower is better utilized for paying cargo.
 

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Old school marine engines, like old school automotive engines, could be reversed on the fly. Spark timing was controlled by a manually operated lever that could be thrown over for reversing the engine. The engine did have to be idled down to low rpm to be successfully reversed without actually stopping and restarting. Those old engines were started by manually spinning the flywheel (marine and industrial), or turning a crank at the front of the car.
Interesting, I was only aware of the reverse rotation for a twin-screw scenario. How is the camshaft/valve timing issue handled?
 

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I have no idea. I've seen two in operation. The first was before I had much knowledge of mechanical things when I was about 10 years old. The second one, I had an opportunity to run as a teenager, but my interests gravitated more towards getting my pilot's license at the time than figuring out antique engines.

I would have to assume that the camshaft would be symmetrically ground to provide the same valve timing in either direction of rotation. The only change necessary then would be to the manually controlled spark timing. (I think.)
 

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I have no idea. I've seen two in operation. The first was before I had much knowledge of mechanical things when I was about 10 years old. The second one, I had an opportunity to run as a teenager, but my interests gravitated more towards getting my pilot's license at the time than figuring out antique engines.

I would have to assume that the camshaft would be symmetrically ground to provide the same valve timing in either direction of rotation. The only change necessary then would be to the manually controlled spark timing. (I think.)
I couldn't quite rationalize this one as the sequences of the came lobes on a 4-stroke engine are roughly (again, roughly) 90 degrees, not 180. Reverse the rotation without changing the came, and the exhaust becomes the intake, the intake the exhaust. Timing of the valves is not a true 90 either due to overlap in exhaust/intake strokes. After googling (could not find a reputable source) this, seems they may have been diesel engines where the intake and exhaust become relative to the direction the engine is turning. Given diesel have always been fuel-injected, adjusting the timing of the pump is simpler.

Or perhaps they were two-stroke engines and it simply was just a matter of changing the spark timing...

Interesting concept nonetheless.
 

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I couldn't quite rationalize this one as the sequences of the came lobes on a 4-stroke engine are roughly (again, roughly) 90 degrees, not 180. Reverse the rotation without changing the came, and the exhaust becomes the intake, the intake the exhaust. Timing of the valves is not a true 90 either due to overlap in exhaust/intake strokes. After googling (could not find a reputable source) this, seems they may have been diesel engines where the intake and exhaust become relative to the direction the engine is turning. Given diesel have always been fuel-injected, adjusting the timing of the pump is simpler.

Or perhaps they were two-stroke engines and it simply was just a matter of changing the spark timing...

Interesting concept nonetheless.
Try this. The cam timing gear is normally keyed to the camshaft. What if it could move on the cam and drove a stop block on the cam instead? Depending on the relationship of the stop block, cam timing could be changed 180°.

Since the rotation could only be changed at dead slow speed, the impact would not be great since much of the energy from the cylinder that fired out of sequence would be soaked up by reversing the mass of the flywheel, crank, and reciprocating parts. Once cam timing was changed, the rest of the cylinders would fall into sequence and spark timing could be adjusted for proper spark advance in the opposite rotation.

Just a thought. The mechanics, machinists, and engineers of days gone by created most of what we use today. We just advance the development that they started.

Yup, it's an interesting concept. I hadn't thought of those engines for almost 60 years. That generation did for mechanicals what the current generation is doing for computers. Gotta wonder if the any of the current crop of computers will still be working 100 years from now. Yesterday, I saw a Model T driving down the road into town, and it wasn't a hot rod judging by the wood spoke wheels and slow acceleration.
 

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Try this. The cam timing gear is normally keyed to the camshaft. What if it could move on the cam and drove a stop block on the cam instead? Depending on the relationship of the stop block, cam timing could be changed 180°.

Since the rotation could only be changed at dead slow speed, the impact would not be great since much of the energy from the cylinder that fired out of sequence would be soaked up by reversing the mass of the flywheel, crank, and reciprocating parts. Once cam timing was changed, the rest of the cylinders would fall into sequence and spark timing could be adjusted for proper spark advance in the opposite rotation.

Just a thought. The mechanics, machinists, and engineers of days gone by created most of what we use today. We just advance the development that they started.

Yup, it's an interesting concept. I hadn't thought of those engines for almost 60 years. That generation did for mechanicals what the current generation is doing for computers. Gotta wonder if the any of the current crop of computers will still be working 100 years from now. Yesterday, I saw a Model T driving down the road into town, and it wasn't a hot rod judging by the wood spoke wheels and slow acceleration.
Along with the interesting discussion on this the one thing that stuck out to me on an engine running backwards was what about the oiling system? Obviously this doesn't apply to all engines but in a conventional setup the pump would run in reverse.
In a situation where you could actually get the engine to run backwards I guess you'd have to have some different oiling setup.
 

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