No fire on cylinder 4

[BackyardKrazy]

Ill try that tonight, but what I dont understand is why i have continuity between 12v and ground all the way back to the solenoid?

 

[Jiggz]

How much continuity are you referring to? The rectifier can read low resistance in forward and almost infinity in reverse. Additionally, the starter solenoid control circuit is also in parallel with the rectifier. So if you have your red probe on the solenoid positive terminal (either the large or small terminal) and the black probe to the ground, then you are reading the solenoid control coil resistance.

And since the rectifier is in parallel, if you have your red test probe on the rectifier red wire and the black probe to ground, you will still read resistance. Now if the rectifier is totally disconnected, meaning both input and output wires are disconnected, then there only be low resistance between the rectifier and ground in forward reading and high resistance in reverse reading.

Try the above test first with the rectifier disconnected and see if that will improve engine performance. if it does, most likely you need to replace the rectifier. And you can just get the Radioshack one for less than $5.

 

[Derrick Fronckowiak]

[FONT=&quot]BackyardKrazy, you should have two separate issues going on here. Your stator has three separate circuits on it. One coil (that is wrapped around half of the circumference of your stator) is your battery charging circuit (you might notice that the wire gage wrapped on the stator core is thicker than the windings on the other half of the coil). The other half of your stator has finer wire wrapped around the core and has four leads coming off of it, those are your charge coils for your ignition (a very simple magneto that uses the flywheel center magnet to induce a voltage in the coils), and that is as close as your ignition circuit comes to your charging circuit (except where the kill wires go to your ignition switch). As far as your ignition problem goes, I can share what I've recently experienced on my Force 90 (3 cylinder) engine. I had a loooooong bout with troubleshooting a non firing cylinder. Like many others I switched packs, switched coils to see if the problem would move from cylinder to cylinder. And it did, so naturally I thought I had a bad pack. I ordered and got a "new" one (ebay), swapped out one pack and my problem "seemed" to go away.....until it came back very shortly thereafter. I was frustrated. Then as I was reading out resistance in my trigger, stators, coils (everything for the zillionth time) I learned that a few of the wires that come out of the packs and connect to the trigger leads actually had intermittent opens at the terminal ends (the one that corresponded to my dead/non-firing cylinder). Through all my troubleshooting of taking off the leads and putting them back on again, over and over, I weakened the connections (made them brittle through work hardening) at the terminal where the wire goes in to the point that I was getting an intermittent open. Here's an EASY (and cheap) way to test for that (you hardly have to take anything apart). Disconnect the wire pair for the non-firing cylinder that go from your pack to your buss bar (I think it is for your #4 cylinder, right?). Take your multimeter, set it on resistance (ohms) and attach one end to the ground point on the ignition module frame (make sure you're on a good ground). Take the other multimeter lead and attach it to one of the two pack leads that you just disconnected. One of the two leads should read about 600 to 700 ohms, while the other will read just a couple ohms. But more important than the resistance reading is the continuity. As you read the resistance flex each terminal, hold the wire still and flex the terminal to see if the resistance flashes between a resistance reading and infinity (open). If it does, then either re-solder the terminal or just strip and replace the terminal. If fact, if you are in any doubt as to the terminal's integrity, just re-solder it or replace the terminal (and that goes for the packs, the trigger and the stator, or any leads) . I learned an expensive lesson from this. The old adage about troubleshooting shines through....check the simple stuff FIRST. Let us know how it goes.[/FONT]

 

[Derrick Fronckowiak]

Excuse me, I meant the outer magnet (not inner) induces a voltage in the stator windings. Again, my recommendations are based specifically on what I just recently experienced. It's a simple thing to check for (and fix if necessary) before you go replacing expensive ignition components.

 

[BackyardKrazy]

ok, so the rectifier tests bad. + to one of the ac points has 500osh ohms one way and not the other, and the other ac terminal has nothng either way. same for testing off the neg pole.


So... will this make my engine work like crap? Or just not charge? Can I run it disconnected until I get one? Summer is too short....

I called The Source ( Canadian Radioshack) and they no longer sell the rectifiers.

Ebay has this:
Will it work?

 

[BackyardKrazy]

will this work?




Its a 3 post, it just uses the base as ground. I can get this through my work in 3 days.....

 

[Jiggz]

Yes, before spending more $$$. Disconnect the rectifier on both sides, input and output. Just make sure the disconnected wires are insulated and not shorted to ground or to each other. And yes, the motor will still run without the rectifier albeit it will not be charging. The charging circuit is only for aux equipment. The motor has its own electrical power coming off the stator 2nd circuit (blue yellow wires) connected directly to the CDMs.

 

[Jiggz]

Definitely do not need a regulator considering the charging circuit is rated only at 7 amps or a total of 84 watts. The rectifier you posted does not show the voltage and current ratings. But if it is rated for 12Volts and at least 7 amps or higher it should be OK.

 

[BackyardKrazy]

OK, Small update. I drove over to the lake, and backed the boat into the water. Since it was a smaller lake and i didn't want to interrupt the fishermen, I ran it on the trailer so i could put some load on the engine in gear. It "seemed" to be better, although I didn't have a tach to go by but when listening to the engine it sounded smoother. It didn't stall going into gear like it had been idling too low from not firing on all four cylinders.

But it also didn't want to shut off with the key.... Strange?

Im going to search high and low today to for a rectifier, and also make sure the AC wires aretn shorted to ground like Jiggz has mentioned.

Thanks for all the advice guys, I'd be lost otherwise.

 

[Jiggz]

Double check the shut off wires from the engine terminal. This is the two white wires to make sure it is not loose. Additionally, you can check the ignition switch to make sure it also works. To do so have another person operate the key or you can just do it yourself except you have to go back and forth between the ignition switch and the engine terminal board.

With the ignition switch in the "Off" position, read continuity between the white wires on the engine terminal board to ground and there should be a very good continuity.

Next, with the ignition switch in the "On" position, read continuity between the same wires and ground and there should be NO continuity.

Do the checks multiple times to ensure the ignition switch is not loose and intermittent. Remember, the above checks should be done with the "Kill switch" (Lanyard switch) set to operate and not activated. To clarify, when kill switch is activated, i.e. removed, it will "Kill" or shut down the motor. It does this by hard grounding the white wires to ground. You cannot re-start the motor without re-setting it. You can crank the motor alright but it will never fire because the CDM's are grounded.

 

[Derrick Fronckowiak]

Jiggz - Could his ignition switch have an open to the kill wires? That switch should be grounding out the ignition when the key is turned off, and speaking of grounding could that also be part of his charging problem (faulty, inadequate or otherwise intermittent ground) that may have jacked up his rectifier?

 

[Jiggz]

Exactly the reason why you do continuity test as delineated in the previous post. The charging circuit is totally independent of the ignition circuit. It maybe in parallel but independent and shares no common wires except at the solenoid terminal.

 

[BackyardKrazy]

Hey Guys, I got my new rectifier today. Started it in the driveway on the muffs, and it really didnt run that well. Remembered it wouldn't turn off with the key, and started following the directions Jiggz had given. Switch worked perfectly, i joggled the key... tried it 20 times. Worked normal. So I started following the kill wires over the engine, and looking around noticed the main ground wire that bolts to the coil bracket broke off! Im not sure why it even ran, the coils weren't grounded..

I replaced the wire (it was turning black inside) and hit the lake. Idling shortly after being started, it coughed repeatedly. UGH... I got out into some deeper water and it took off perfectly! Smooth acceleration straight up to 5000 RPMS. Fantastic... but at idle, it missed and coughed.

Got home, put the muffs on, and noticed to get my idle up to 1200, I had my idle adjustment cranked out which also move the timing ahead. So i turned that back out, and readjusted the cam bolt on the throttle To use more carb and less timing to achieve idle.. Fine tuned it and it seemed to be a lot better-in the driveway.

Im going fishing tomorrow come Hell or High water, ill keep you posted afterwards.

 

[Jiggz]

Good on you and enjoy!