82Caddy 851 #1 Posted August 4, 2016 K341 in a D series with no spark. Prior to doing anything I have done, there was an intermittent spark/no start issue. Was generally resolved by wiggling the ignition switch. Confirmed switch was failing as the contacts were loose. Since the switch was failing and the wiring was pretty haggard, I opted to replace the switch, pigtail and all wires along with a tune up kit. New switch and wiring pig tail. New switch verified good by using it to start my commando 800. Wiring was done as follows: Ammeter is bypassed with a 30 amp fuse to eliminate that as a possible cause. Lights are not wired. Points are new and set at .020 New spark plug and wire with plug gaped at .035 Swapped ignition coil with commando 800 (K181) and creates spark/starts that tractor. Confirmed with key on: 12.5V at + side coil 12.5V at - side of coil 12.5V at points 12.5V at rectifier Result: no spark I'm out of ideas and about to rip this engine out and replace it with another predator twin. What am I missing? Share this post Link to post Share on other sites
Eric Friedrichsen 111 #2 Posted August 4, 2016 Caddy, Your schematic shows you are using a battery ignition system, not a magneto. In a battery ignition system you need to have a set of breaker points wired to the negative terminal of the coil. These points provide an intermittent ground on the coil causing the primary in the coil to collapse thus inducing a high voltage in the secondary which results in a spark at the spark plug. You need to connect the negative side of the coil to the breaker points and the high voltage connection of the coil (secondary to the spark plug. I haven't studied all of your connections closely. This is just what popped out on an initial check. Eric 1 Share this post Link to post Share on other sites
rmaynard 14,897 #3 Posted August 4, 2016 (edited) When you are checking the voltage at the (-) side of the coil, the 12.5v should go off and on as you rotate the engine (points opens and closes). Is that what you find? Edited August 4, 2016 by rmaynard 1 Share this post Link to post Share on other sites
82Caddy 851 #4 Posted August 4, 2016 (edited) 9 minutes ago, Eric Friedrichsen said: Caddy, Your schematic shows you are using a battery ignition system, not a magneto. In a battery ignition system you need to have a set of breaker points wired to the negative terminal of the coil. These points provide an intermittent ground on the coil causing the primary in the coil to collapse thus inducing a high voltage in the secondary which results in a spark at the spark plug. You need to connect the negative side of the coil to the breaker points and the high voltage connection of the coil (secondary to the spark plug. I haven't studied all of your connections closely. This is just what popped out on an initial check. Eric Negative side of coil is wired to breaker points. New wire and connectors there as well. 9 minutes ago, rmaynard said: When you are checking the voltage at the (-) side of the coil, the 12.5v should go off and on as you rotate the engine (points opens and closes). Is that what you find? I'm not sure. I'll have to check this evening. I didn't have 3 hands to hold multimeter ends and rotate the engine. I'll enlist the help of the Mrs and check. I also can't find my test light... Edited August 4, 2016 by 82Caddy Poor spelling Share this post Link to post Share on other sites
Achto 26,551 #5 Posted August 4, 2016 1 hour ago, 82Caddy said: Points are new and set at .020 New spark plug and wire with plug gaped at .035 Swapped ignition coil with commando 800 (K181) and creates spark/starts that tractor. Did you also replace the condenser? 1 Share this post Link to post Share on other sites
82Caddy 851 #6 Posted August 4, 2016 Just now, achto said: Did you also replace the condenser? Sorry, I missed that condenser was replaced with a new one. Both (I guess technically 3) start and operate the K181, so condenser is good. Share this post Link to post Share on other sites
Achto 26,551 #7 Posted August 4, 2016 (edited) Sounds like your points may not be operating properly. Here's some simple visual checks. Remove the points cover and roll the engine over by hand to prove that they are opening and closing. If that checks out, have someone try to start the engine while you watch the points you should see some blue sparking from the points. If there is no sparking try cleaning the points by sliding a dollar bill through them while they are closed. Then watch for the blue sparks again. New points some times have a coating on them that hampers their performance. Best of luck. Edited August 4, 2016 by achto 3 Share this post Link to post Share on other sites
Achto 26,551 #8 Posted August 4, 2016 2 hours ago, 82Caddy said: Sorry, I missed that condenser was replaced with a new one. Both (I guess technically 3) start and operate the K181, so condenser is good One more question, is the spark plug good? May seem to be a dumb question but sometimes we over look the obvious. Just to make sure I will stick a screw driver on the plug wire and hold it close to a ground to see if I get a spark across while cranking. Share this post Link to post Share on other sites
82Caddy 851 #9 Posted August 4, 2016 Just now, achto said: One more question, is the spark plug good? May seem to be a dumb question but sometimes we over look the obvious. Just to make sure I will stick a screw driver on the plug wire and hold it close to a ground to see if I get a spark across while cranking. On the K181 (for testing purposes) the plug and wire (from k341 and k181) both create spark with the coil/condenser from the K181 and with the coil/condenser from the k341. I tried various combinations of parts to ensure there wasn't something wrong with the components on the K341. The only thing I didn't swap was the points because I didn't want to reset the working k181. I even swapped the wiring from the k341 I made into the K181 and it fired right off. It's looking and sounding like the points are the culprit here. I can't confirm that yet, but will look tonight. 1 Share this post Link to post Share on other sites
82Caddy 851 #10 Posted August 5, 2016 Well this is embarrassing. Put all the tune up parts back on the k341 with a new spark plug, re-gaped points again (what feels like the millionth time) and turned the key. Cranked for a second and popped off. Runs great now to sort out a few other issues with this tractor before winter hits. Thabks for the help all. 2 Share this post Link to post Share on other sites
953 nut 51,677 #11 Posted August 5, 2016 35 minutes ago, 82Caddy said: Runs great Share this post Link to post Share on other sites
R. L. Addison 299 #12 Posted January 4, 2017 (edited) I have also run into a sticky push rod to points. Wiped it off with fine emery cloth & ran fine. Not a common problem, just my 2 cents. Edited January 4, 2017 by R. L. Addison Share this post Link to post Share on other sites
