MS201TC - No Spark

[louie3888]

Hey,

I'm rebuilding an MS201TC with a missing carb and broken handle. It was an auction saw so I do not have much history, pretty rough. With the handle on order and carb is it possible to test the spark by keeping the broken handle in which the wires look in good shape in the <ON> position not having the carb plugged in? Also, the yellow coating is pretty far removed from the flywheel, some still on no other damage to it. I have heard that not having the yellow coating can cause the saw not to signal due to magnetic field disruption. However, on older say, I can swear I remember seeing the yellow coating with no computer-aided ignition module, like corrosion protection. I don't know the real answer for that, just wanted to see if I had to have everything all plugged together for a basic spark test. Any option to emulate the solenoid with like a resister of some sort? Any thoughts? Thank you, Louie!

 

[Woodslasher]

Hey,

I'm rebuilding an MS201TC with a missing carb and broken handle. It was an auction saw so I do not have much history, pretty rough. With the handle on order and carb is it possible to test the spark by keeping the broken handle in which the wires look in good shape in the <ON> position not having the carb plugged in? Also, the yellow coating is pretty far removed from the flywheel, some still on no other damage to it. I have heard that not having the yellow coating can cause the saw not to signal due to magnetic field disruption. However, on older say, I can swear I remember seeing the yellow coating with no computer-aided ignition module, like corrosion protection. I don't know the real answer for that, just wanted to see if I had to have everything all plugged together for a basic spark test. Any option to emulate the solenoid with like a resister of some sort? Any thoughts? Thank you, Louie!

I know for standard saws you can just remove the kill switch wires to test for spark, if this is a M-tronic unit then I have no idea what the usual testing procedure is.

 

[louie3888]

Yes, it is an M-Tronic system. Look like the constant ground is good (yellow), the (black) kill wire checks out when engaged, and red also checks out to the coil terminal. Seems like the handle still works even though the backside is broken. The coil will not make a spark when connected and since I do not have the carb with the solenoid wondering if the electronic ignition module requires that to fire.

 

[Woodslasher]

That I do not know. My cumulative experience with M-tronic saws has been limited to blowing off and scrubbing down a MS362, followed by briefly test running it. Hopefully someone with more knowledge about them will chime in shortly.

 

[louie3888]

I hope so. Wondering if anyone tried to unplug the carb connector an got spark, or found some other way to test the coil? Thanks

 

[sawfan123]

I hope so. Wondering if anyone tried to unplug the carb connector an got spark, or found some other way to test the coil? Thanks

No. System must be intact. The new carb, if oem will have the sol. Changing handle without a new harness is a bad idea. Sometimes it’s better just to get the handle assy, with has the harness included. As for testing, process of elimination. Control unit is last.
There were two different style handles. They had different connection at control unit. Same with harness.
And the harness always tests good.

 

[louie3888]

Okay, thank you for the feedback. I guess I will have to wait for the carb to arrive before any additional testing. I did perform a resistance test on the harness and the different positions seem clean, even engaging the trigger for different positions. Guess as a best practice I can look at the harness, just was hoping there was a way to rule out the coil without using a manufacturer diagnostic test tool. I also, read some posts where a double AA battery was being used to simulate the solenoid.

 

[sawfan123]

I not sure it simulates the solenoid. I thought it can be used to activate it.
But I never remember one failing electrically. They leak. Now there’s
a new green one that all but solved
that problem.
Just a word of caution, just because the harness checks ok doesn’t mean it is.

 

[louie3888]

After fixing the handle, a good cleaning, replacing parts, and installing a used carb since the original was missing this dead auction saw is ready for work again. Thank you for the help. Without having everything connected no good way to test spark.
View attachment MS201TC.MOV