MS270 coil?

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Same as above, the one from Farmertec worked fine on that saw. If my memory is correct, the coil for that saw is mounted directly on the cylinder, stupidest place to mount it as heat is the big enemy of semiconductors in the coil.
 
Have you checked you’re not getting a short to ground from the HT lead or Kill wire? It’s also also good to check the spring in the plug boot is well connected via the spike to the HT lead.
Good advice and about the only thing you can check on an electronic module using an ohm meter. Measure the resistance from the inside of the plug lead cap to the cylinder, should be over 5k and that will verify the plug lead, coil secondary and the grounding of the coil to the cylinder. Just pull the kill switch wire off the coil to see if it makes any difference to the spark.
 
Good advice and about the only thing you can check on an electronic module using an ohm meter. Measure the resistance from the inside of the plug lead cap to the cylinder, should be over 5k and that will verify the plug lead, coil secondary and the grounding of the coil to the cylinder. Just pull the kill switch wire off the coil to see if it makes any difference to the spark.
Pulled the kill wire switch off the coil, no spark.
Less than 2k ohms when checking with ohm meter??
 
Same as above, the one from Farmertec worked fine on that saw. If my memory is correct, the coil for that saw is mounted directly on the cylinder, stupidest place to mount it as heat is the big enemy of semiconductors in the coil.
The coil is mounted to the cyl. Found this coil on Amazon withe a decent review.
PARTSRUN 1133-400-1350 Ignition Coil for STIHL???
 
look over the coil for any trash, i have on more than one occasion found steel wires, drilling curls and other forms of metal against the coil causing a kill condition. I prefer a used oem off ebay over a chicom coil if they are not stupidly priced.
 
Good advice and about the only thing you can check on an electronic module using an ohm meter. Measure the resistance from the inside of the plug lead cap to the cylinder, should be over 5k and that will verify the plug lead, coil secondary and the grounding of the coil to the cylinder. Just pull the kill switch wire off the coil to see if it makes any difference to the spark.
Spot on, I think I saw a post of yours a while ago about semiconductors surrounding the primary windings or something? Giving you inaccurate readings on primary using an MM? Good advice, I’m aware that to get an accurate reading you need to supply higher current than a mm can offer. I dont understand how a semiconductor works in combination with primary windings though. I did research it but couldn’t understand.
 
Spot on, I think I saw a post of yours a while ago about semiconductors surrounding the primary windings or something? Giving you inaccurate readings on primary using an MM? Good advice, I’m aware that to get an accurate reading you need to supply higher current than a mm can offer. I dont understand how a semiconductor works in combination with primary windings though. I did research it but couldn’t understand.
In the old points/magneto system, the points opened when the current in the primary windings was at a maximum and the opening of the points started a spike in primary voltage that was multiplied to a much higher voltage by the secondary of the coil. In electronic modules, the function of the points has just been replaced by a semiconductor switch in addition to some circuitry that allows the timing curve to be modified. Without access to the circuitry, the operation of the semiconductors cannot be tested with an ohm meter, regardless of the current output of the meter. One end of the secondary winding and one end of the primary winding are both connected together and must be grounded to the cylinder to give a complete path for the spark discharge. With electronic modules, the common ground for both windings is connected to the coils' laminated core which is in turn grounded to the cylinder. If you check the resistance from the plug lead to the cylinder, you are checking the resistance right from the spark plug, through the coil secondary, through the coil core and right to the cylinder. 2k sounds way too low. Usually it is the semiconductor package that fails in these coils but the secondary can also be damaged by pulling the engine over fast with the ignition on and the plug out and no path to ground for the spark.
 
In the old points/magneto system, the points opened when the current in the primary windings was at a maximum and the opening of the points started a spike in primary voltage that was multiplied to a much higher voltage by the secondary of the coil. In electronic modules, the function of the points has just been replaced by a semiconductor switch in addition to some circuitry that allows the timing curve to be modified. Without access to the circuitry, the operation of the semiconductors cannot be tested with an ohm meter, regardless of the current output of the meter. One end of the secondary winding and one end of the primary winding are both connected together and must be grounded to the cylinder to give a complete path for the spark discharge. With electronic modules, the common ground for both windings is connected to the coils' laminated core which is in turn grounded to the cylinder. If you check the resistance from the plug lead to the cylinder, you are checking the resistance right from the spark plug, through the coil secondary, through the coil core and right to the cylinder. 2k sounds way too low. Usually it is the semiconductor package that fails in these coils but the secondary can also be damaged by pulling the engine over fast with the ignition on and the plug out and no path to ground for the spark.
 
Thanks to everyone for the replies. I am going to get the coil from Amazon & hope for the best. This is not my saw and the owner does not want to put too much money in it.
 
The more I look the worse it gets. I was told the flywheel came off while he was running it. There is a fin broken off the flywheel. What will this do to the balance running at 10,000 rpm?
 
The more I look the worse it gets. I was told the flywheel came off while he was running it. There is a fin broken off the flywheel. What will this do to the balance running at 10,000 rpm?
One broken fin won't make any difference but the fact that the FW came off while running could be significant. Might mean the FW key has been sheared and there could be physical damage to the coil when it came off. Does the coil look damage free and was it mounted with the correct gap from the FW? Gap should be set with a standard business card. VERY unusual for a FW to actually come off, but if it does, there should be damage to the starter drive and the coil.
 
One broken fin won't make any difference but the fact that the FW came off while running could be significant. Might mean the FW key has been sheared and there could be physical damage to the coil when it came off. Does the coil look damage free and was it mounted with the correct gap from the FW? Gap should be set with a standard business card. VERY unusual for a FW to actually come off, but if it does, there should be damage to the starter drive and the coil.
There is no damage to the coil, FW key, or starter. The flywheel had some burrs. I think the coil has been replaced. The IPL for this saw calls for 1133 400 1350 coil.
Numbers on the coil that's installed is "1133 1301 A" "AV 1133 " "TMO 51"
It is a Sthil coil. Also the IPL calls for a 1133 405 6600 Ring. I do not see this part on this saw.
 
I put a Pro Line coil on a ms 270 that was giving me grief. # 1133 400 1350 is the part number...
It runs as at should now, 3 plus cords of firewood on it ... It was 39.95 on Fleabay...
 
First off, thanks to all for the replies.
I installed this coil (PARTSRUN 1133-400-1350) purchased from Amazon. Installed it yesterday & the saw started on the second pull. Time will tell how long it lasts.
 
There is no damage to the coil, FW key, or starter. The flywheel had some burrs. I think the coil has been replaced. The IPL for this saw calls for 1133 400 1350 coil.
Numbers on the coil that's installed is "1133 1301 A" "AV 1133 " "TMO 51"
It is a Sthil coil. Also the IPL calls for a 1133 405 6600 Ring. I do not see this part on this saw.
The ,ring , looks like a grommet. Does the high tension wire/sparkplug wire pass through the crankcase on its routeing between the coil and the sparkplug ?
 

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