Bosch Blue coil

[jack casey]

I have a Cub Cadet 102 with what looks like an oem coil. The K241 engine cranks a bit slow, 2-3 seconds, but always starts. Strong battery. Coil is attached to engine as you can see in pix and with multimeter I tested resistance, numbers flying all over. Was hoping against hope for 3.5 ohms or so. Again, the tractor starts and runs even with the flying numbers. What to do? Think the Bosch helps with cranking, what are other benefits?
Searched the forum w/o luck.
Thanks, Jack

 

[Everettlee]

Are you saying you want to replace a coil that works fine? Slow crank will still happen no matter what coil

 

[bwstevens]

It has a starter generator so slow cranking is built in. The starter wires and battery needs to be up to the task rather than changing the ignition coil.

 

[jack casey]

It has a starter generator so slow cranking is built in. The starter wires and battery needs to be up to the task rather than changing the ignition coil.

Thanks guys for responding. But what explains the poor test results, I tested post to post and get repeated crazy resistance numbers, never seeing 1.5 or even 3.4. After 10 seconds of craziness the meter settles at 1.000
Help, Jack

 

[fcurrier]

Does this help?

 

[dkirk]

Be sure you have a good multimeter. The cheap Chinese-made devices are highly inaccurate. You should see 3.4 - 4.0 ohms on the primary with a steady and consistent reading.

 

[fcurrier]

OK, Dave, are we talking analog or digital multimeter. Are we trying to take a reading with that sucker running? Merry Christmas from Northern Maine!

 

[jstich]

You will not get "correct" resistance readings unless you disconnect the the wires from the terminals, because you are "charging" the condenser. After it is charged the resistance will stabilized but the reading will include the coil and the condenser and not the 3-4 ohms that you are expecting.

 

[fcurrier]

You will not get "correct" resistance readings unless you disconnect the the wires from the terminals, because you are "charging" the condenser. After it is charged the resistance will stabilized but the reading will include the coil and the condenser and not the 3-4 ohms that you are expecting.

 

[dkirk]

Frank, engine not running and primary wires disconnected as Jerry says. Either digital or analog multimeter is okay as long as you spent $100 or more for it. Best of luck and Merry Christmas to you from Central Wisconsin.

 

[jstich]

$100 to prove that a working coil is not bad? Not going to happen in this lifetime. Ho, Ho, Ho.
Just show me a big blue spark off of the big wire and no smoke off the little wires and I'm a happy camper. I have several of those $100 meters but the big blue spark test is much more accurate.
Otherwise....
Yellow Spark=Bad Condenser
Tiny or no Spark; "Borrow" an emery board from your wife and clean the points.
Ho, Ho, Ho, Merry Christmas.

 

[jack casey]

You will not get "correct" resistance readings unless you disconnect the the wires from the terminals, because you are "charging" the condenser. After it is charged the resistance will stabilized but the reading will include the coil and the condenser and not the 3-4 ohms that you are expecting.

I searched the 'net for proper way to test a coil, one site (forget which one) said ok if wires connected. Wrong! Multimeter is a Micronta 22-184, it be old but never fails. So, ignition off, two wires and spark plug cable removed - get 04.3 ohms, just the two wires removed - get another 04.3, expected that. At another time today, earlier, got 4.8 ohms. Too high?
Jac k

 

[mgonitzke]

That resistance is within the range in the diagram fcurrier posted. Coil is fine. You seem to be searching for a problem where one does not exist.

 

[jack casey]

That resistance is within the range in the diagram fcurrier posted. Coil is fine. You seem to be searching for a problem where one does not exist.

Was concerned with slow cranking, which I find is normal. Thanks.
Merry Christmas

 

[mgonitzke]

Slow cranking would be caused by a bad battery, corroded, dirty, or undersized battery cables, bad electrical connection on any of the battery or starter cables, bad bearings in starter/generator, worn brushes or commutator in starter/generator, bad armature in starter generator, or non-functioning compression release in the engine. The ignition system has absolutely nothing to do with how well the engine turns over.

 

[dray]

I ran into a problem years ago with the switch, it would lose voltage to the coil when in the crank position but would have voltage when just in the on position . Just a thought.

 

[Beltrack]

Ignition timing too far advanced perhaps

 

[Beltrack]

Speaking of inoperable compression releases, does the K161 have a compression release?

 

[jack casey]

That resistance is within the range in the diagram fcurrier posted. Coil is fine. You seem to be searching for a problem where one does not exist.

I saw Frank's post with diagram but in my readings (online) I was led to believe that 3.5-3.7 ohms was perfect. I got 4.3 and it made me look again at Frank's. All is good. Lotta support from youse guys and I am thankful.
Jack

 

[Everettlee]

My experience is coils are either good or fail miserably. I have not found one in a gray area