Mantis-20 tiller

[mony0_8]

My mantis isn't firing, does anyone know what the ohms should be for the cdi and coil?

 

[grcauto]

It's a mag isn't it? Just replace it.

 

[billr]

I find very little info for a "Mantis 20"; and am surprised it would have CDI. What makes you think it is CDI? Maybe post pix of the engine/ignition components. Does this coil have two windings (primary and secondary), or is there only one high-voltage winding?

 

[mony0_8]

It's one of the first models, magneto and coil separate. Was running fine and quit. Not firing and hard to find parts.

 

[mony0_8]

Have resistance but not sure if its correct.

 

[grcauto]

Resistance checks on coils is only valid if the test fails. That means only no resistance or open is valid.

 

[billr]

Secondary maybe 10K ohms, or more. The primary will only be an ohm or two, too low to measure accurately with a common multimeter.

Does this have breaker-points; have you chased that black to find out what it connects to in the crankcase? Where is the flywheel/magnet in that picture?

To me, "CDI" means "Capacitor Discharge Ignition", much more complicated than what appears in the picture, and much more expensive than justified for a small engine like this. Again, why do you think it is CDI???

 

[mony0_8]

Haven't pulled the flywheel but can see part of the magneto under it. I've been building 2-stroke 66/80cc bike engines for a few years and they have the CDI is why I thought it was one also.

 

[mony0_8]

It is a CDI. 4.9k at coil and .64k at magneto.

 

[billr]

Well, I read-up enough on Kioritz/Echo/Yamabiko engines to believe that is CDI, not Kettering. I better leave you be. I have no clue what all the bits and pieces of that system are, much less what typical coil resistance would be.

 

[grcauto]

Weak spark or none? If the magnet is strong just throw a coil on it.