Sachs won't turn over

jay cohen · December 29, 2006, 12:53:50 PM

I've started my Six Days a bunch of times and it generally starts after a few kicks when cold. Wouldn't start today so I pulled the plug to see if it had spark. When I went to spin the engine with the kickstarter it wouldn't budge. Tried to kick it and it still won't move. What's up? Did I flood it so much it won't turn over?

Dwight Rudder · December 29, 2006, 01:07:44 PM

Was the plug wet ? If so be careful and not bend a rod or break something. ALSO, BE SURE TO GROUND THE KILL BUTTON. YOU DON'T WANT TO THE SPARK PLUG TO SPARK NOR DO YOU WANT TO BURN UP THE MOTOPLAT OR THE BIKE!
Dwight

Dwight Rudder
7 time ISDT / E medalist
8 time National Enduro Class Champion.

jay cohen · December 29, 2006, 04:18:15 PM

I pulled off the sidecover and tried to rotate flywheel. It wouldn't budge clockwise but would turn counterclockwise. Then tried again clock and it turned motor. I gently tried the kickstarter and it turned over the engine now. I was worried a wristpin clip could have come loose and jammed in the bore somehow. I pulled the head to make sure the piston went up and down and all looks and sounds good. I did not pull the cylinder. Should I pull it off? Could it have been something with the kickstarter? As always, thanks for any help, much appreciated. I received my new Penton calendar today, thanks Randy. It'll go in my classroom at school, I'm a high school science teacher. I'm almost home on this project. Was hoping to ride it today, but now need a new screw plug for the oil drain on gearbox sidecover. Not in any huge hurry because I want all perfect before I try to ride it. I needed to order an extra long, 132 link chain to go with my new 60 toother in the rear/14 front and will pick up the chain tomorrow. Hope the 132 fits as a 130 was too short.
Jay, Restoring to ride and race a '72 Six Days

dkwkid · December 29, 2006, 05:27:12 PM

Could you have knocked some dirt-mud or other into the sparkplug hole while removing the plug? I would be VERY careful about starting the bike up until a positive reason for the lockup was determined.
If you are running the Bosch magnito carefully inspect(remove flywheel).Maybe the trigger coil on the Motoplat hit something.Sometimes the flywheel picks up little washers and such while you have it off for a reason and you do not see it when you re-install.That can cause problems too.
Just my 2 cents.
Glenn

Larry Perkins · December 30, 2006, 07:17:51 AM

Jay,

My gut feeling is that your gas valve is not shutting off and the cylinder is full of fuel. That is why clockwise it won't turn because it can not compress the liquid. When you turn it counter-clockwise then it can go down. Might check this out. The KTM motors have a crank drain but unfortunately the Sachs motor does not.

Larry P

t20sl · December 30, 2006, 09:32:19 AM

Jay:
I would agree it could be something keeping flywheel from turning or maybe the primary drive gears on left side. (clutch basket and crank gear). Your guess about kickstarter gear could also be the case. I would probably pull cylinder just to be sure nothing found its way in there from intake or pin keeper too.
Larry:
I know you have a lot of knowledge on these but have you ever seen a 2 stroke hydraulic lock from gas??? 4 strokes for sure, but wouldn't gas run out the exhaust port or down the transfers before that could ever occur? On a 2 stroke it would have to fill bottom end completely first and then up the transfers, out the exhaust, fill up the exhaust pipe to a level even with the carb. This would also assume the exhaust was sealed good enough to have the tiny stream of gas coming from a leaking float valve to overwhelm the exhaust pipe gasket to cylinder leak that would probably be occuring. I don't think it could happen. Ted

Larry Perkins · December 30, 2006, 10:44:22 AM

No, I have not seen that much but know of and had one KTM motored MC5 that completely filled the crank and would not turn. Probably just flukes and your thoughts seem more likely after more thinking.

Larry P

jay cohen · December 30, 2006, 05:19:26 PM

Thanks for everyone's input. I checked it out and the only answers I have are that either it was related to the kickstarter or the engine was flooded. When I put it together and before I put the tank on it, I gave the kickstarter a little swing and it fired right up and sat there and idled w/o the tank on it. I just got back from riding it around for about an hour and it ran great. If I could figure out how to add pictures of it I'd put it on asap.

Dwight Rudder · December 29, 2006, 01:07:44 PM

Was the plug wet ? If so be careful and not bend a rod or break something. ALSO, BE SURE TO GROUND THE KILL BUTTON. YOU DON'T WANT TO THE SPARK PLUG TO SPARK NOR DO YOU WANT TO BURN UP THE MOTOPLAT OR THE BIKE!
Dwight

Dwight Rudder
7 time ISDT / E medalist
8 time National Enduro Class Champion.

jay cohen · December 29, 2006, 04:18:15 PM

I pulled off the sidecover and tried to rotate flywheel. It wouldn't budge clockwise but would turn counterclockwise. Then tried again clock and it turned motor. I gently tried the kickstarter and it turned over the engine now. I was worried a wristpin clip could have come loose and jammed in the bore somehow. I pulled the head to make sure the piston went up and down and all looks and sounds good. I did not pull the cylinder. Should I pull it off? Could it have been something with the kickstarter? As always, thanks for any help, much appreciated. I received my new Penton calendar today, thanks Randy. It'll go in my classroom at school, I'm a high school science teacher. I'm almost home on this project. Was hoping to ride it today, but now need a new screw plug for the oil drain on gearbox sidecover. Not in any huge hurry because I want all perfect before I try to ride it. I needed to order an extra long, 132 link chain to go with my new 60 toother in the rear/14 front and will pick up the chain tomorrow. Hope the 132 fits as a 130 was too short.
Jay, Restoring to ride and race a '72 Six Days

dkwkid · December 29, 2006, 05:27:12 PM

Could you have knocked some dirt-mud or other into the sparkplug hole while removing the plug? I would be VERY careful about starting the bike up until a positive reason for the lockup was determined.
If you are running the Bosch magnito carefully inspect(remove flywheel).Maybe the trigger coil on the Motoplat hit something.Sometimes the flywheel picks up little washers and such while you have it off for a reason and you do not see it when you re-install.That can cause problems too.
Just my 2 cents.
Glenn

Larry Perkins · December 30, 2006, 07:17:51 AM

Jay,

My gut feeling is that your gas valve is not shutting off and the cylinder is full of fuel. That is why clockwise it won't turn because it can not compress the liquid. When you turn it counter-clockwise then it can go down. Might check this out. The KTM motors have a crank drain but unfortunately the Sachs motor does not.

Larry P

t20sl · December 30, 2006, 09:32:19 AM

Jay:
I would agree it could be something keeping flywheel from turning or maybe the primary drive gears on left side. (clutch basket and crank gear). Your guess about kickstarter gear could also be the case. I would probably pull cylinder just to be sure nothing found its way in there from intake or pin keeper too.
Larry:
I know you have a lot of knowledge on these but have you ever seen a 2 stroke hydraulic lock from gas??? 4 strokes for sure, but wouldn't gas run out the exhaust port or down the transfers before that could ever occur? On a 2 stroke it would have to fill bottom end completely first and then up the transfers, out the exhaust, fill up the exhaust pipe to a level even with the carb. This would also assume the exhaust was sealed good enough to have the tiny stream of gas coming from a leaking float valve to overwhelm the exhaust pipe gasket to cylinder leak that would probably be occuring. I don't think it could happen. Ted

Larry Perkins · December 30, 2006, 10:44:22 AM

No, I have not seen that much but know of and had one KTM motored MC5 that completely filled the crank and would not turn. Probably just flukes and your thoughts seem more likely after more thinking.

Larry P

jay cohen · December 30, 2006, 05:19:26 PM

Thanks for everyone's input. I checked it out and the only answers I have are that either it was related to the kickstarter or the engine was flooded. When I put it together and before I put the tank on it, I gave the kickstarter a little swing and it fired right up and sat there and idled w/o the tank on it. I just got back from riding it around for about an hour and it ran great. If I could figure out how to add pictures of it I'd put it on asap.

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Sachs won't turn over