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Discussion Starter #1
First off, thanks for allowing me to join in. I have not messed with cycles since about 1980. I recently purchased a 1995 Honda fourtrax 300 fw. I bought it not running. I am not getting a spark. I have tested and checked and tested until I am tired of testing. I found a online manual with a wiring diagram and troubleshooting. My wiring colors do not exactly match. I have figured out on the 2 wire connector at the cdi box I am not getting ground on the grey[manual says light green] wire. I do have battery voltage on the black/yellow wire. My neutral light does come on and the engine spins over. I have a brand new Honda cdi box, no change. Coil ohms out to be good as does the alternator. Any help would be greatly appreciated. Thanks in advance.
 

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Welcome to the forum.

I will be glad to help you find spark. Let's start by giving me the VIN. That will help me determine which wiring diagram to use. Typically there is 12v on the black wire with the key on. There is 12v on the gray wire only when the LH lever is pulled in (if the original lever assembly is intact) and the diode is not shorted.
 

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Discussion Starter #3
Thanks for your time in helping me. I think this is the VIN. 478TE1505PA525517. I am using a wiring diagram I found on manualslib.com. It looks pretty close except some colors do not match. Also using troubleshooting from the same place.
 

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You have a 1993 Honda TRX300 FW

90-92 had the same wiring and 94-97 was the same - 93 used it's own wiring diagram separate from the rest

I'm curious, where did you get the new CDI box? What part number did you get? The CDI box you need was only used on 89-93 TRX300 and TRX300FW models. It is a DC CDI - if you got an AC CDI, it will not be of any use. A lot of people make this mistake no knowing there's a difference.
 

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The CDI box you got (30410-HM5-505) is for 94-97 TRX300 and TRX300FW

The CDI box you need is 30410-HC4-770 - they are both DC voltage modules, but they are not compatible or interchangeable. They are designed to operate with different values of peak voltage. They have the same plugs and wires except the 93 has a blue/white wire and a gray wire where the 94-97 has a black white and a green wire on the two pin connector. If you trace the wires, the blue/white of the 93 plugs into the black/white to the handlebar engine stop switch (the 94-97 plugs into the same place they just used different color wires). The blu/wht of the 93 and the blk/wht of the 94-97 both have 12v+ on the wire when the handlebar engine stop switch is in the on or run position.

You should have ground on the gray wire only when the transmission is in reverse.

However, before you get a different CDI module, you need to have a peak voltage tester to determine what the problem actually is. Retest everything using the old CDI box and if you determine the CDI box is the culprit, then get the right one. See if you can rent or borrow a multimeter with a peak voltage function - or an oscilloscope - or a peak voltage adapter for a standard multimeter. Checking resistances is one step of the process, but knowing the peak voltages is key to determining the problem. With a peak voltage tester, you can actually measure the output of the coil to the spark plug.

Generally, the stator fails, the flywheel key shears or another component is responsible for loss of spark. Frequency of failure resulting in loss of spark is; 1) spark plug 2) spark plug cap, 3) wiring connections, 4) switch, 5) battery, 6) stator, 7) pulse generator, 8) CDI module, 9) coil, 10) flywheel key (spark timing), 11) something else.

What have you tested and what were the results of each test?

I can email you the manual or pages from the manual if that would be helpful. Just PM me your email address.
 

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Discussion Starter #8
Thank you for getting me the manual pages I need. Will get back with you when I get around to testing some things.
 

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Discussion Starter #10
Started through the troubleshooting by the pages from the manual. Going down the list on CDI inspection, 17-3, all of the items on that page are within spec. I get to page 17-4,ignition coil, primary coil resistance is .2 ohms. The secondary coil resistance is open, with plug cap and without plug cap. I got a so called good used one, but it ohms out the same way as my original. Do I need to bite the bullet and buy a new Honda coil? Thanks for any help!
 

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Coils are pretty simple - it's just a transformer - 2 windings, sometimes separate and sometimes a center tapped single winding. The coil you are testing is the center tapped variety.

If you did the test right, it sounds like the coil is bad, but coils are very durable and failure is seldom an open winding. I'm not sure that you could have done the test wrong, but what kind of meter did you use - digital or analog? Is the meter self ranging or do you manually select the range?

What the book specifies and what you read are two different things. The only way to get the same readings as the book, you have to have a NEW coil and use the same (or at least the same brand and model) meter that was used when the specs were published. I just checked a good used coil and got 1.0 ohms on the primary and 4.62 on the secondary with the plug cap removed. If you were on the wrong scale, it's possible the resistance was higher than the selected range was capable of reading.

The OEM Honda coil has an MSRP of $61 - dealer cost is $40 - I've had good luck with aftermarket coils - here's one on Ebay that includes a spark plug cap Celox and here's one from a trusted supplier for the same price, but without the plug cap Caltric

If you want to "bite the bullet', I can get you a new OEM coil for $40 plus shipping (about $7)
 

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Discussion Starter #12
Finally got around to digging a little deeper with the troubleshooting. Appears my pulse generator is no good. Any suggestions on purchasing one? I have found some used complete assemblies, stator, alternator, pick up coil, on e-bay. should I go that route or just replace the pulse generator? I do have the side cover off and know that it is a 12 winding. Thanks in advance.
 

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Pulse coil is part number 30300-HA0-033 @ $35 from Honda - it has a plug on it and is easily replaced without replacing the entire stator - according to the information I have available, the stator has 16 poles
 
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