1999 Honda fourtrax300fw no fire

[Outdooreagle 11]

Thanks Jeep 

[Fishfiles 20,145]

You do have a 1999 right ^

Blue / Red = L/R

Brown / Yellow  = ? 

 

you are right the Blue/Red ( L/R ) does go to the thermo sensor

 

I don't even see a brown /yellow on the color code chart on the right , what wire did you ohm? 

 

I believe the way it goes is , in 98-2000 the alarm box and the CDI are one box and the L/R wire goes into the CDI box , on 94-97 there are two separate boxes for alarm and cdi and the L/R wire goes into the kill switch

 

What that all means is , I don't know , yet 

[Fishfiles 20,145]

Wow , in the short time I was gone , there were like 10 post in front of me when I posted  -------  I know Jeep knew about that Rancher CDI  

[Outdooreagle 11]

The blue red ohm out at 17k ohms, however, it’s not 77degrees. I love in south ga so it’s around 60degrees when I tested it. 

[Outdooreagle 11]

Yes Sir. It’s a 1999

[Goober 1,555]

Keep in mind the oil temp sensor Circuit does go to ground through the sensor BUT there is a specified ohm range for the sensor. Normal i think is 9.5KOhm?—so put a lead on the sensor connector and one on the case you should read some resistance.

 

Have you done a circuit test on the kill switch? To access the connector you have to pull the fender and unscrew two bolts from a little plastic box forward of the steering head

[Goober 1,555]

5 minutes ago, Outdooreagle said:

The blue red ohm out at 17k ohms, however, it’s not 77degrees. I love in south ga so it’s around 60degrees when I tested it. 

If warmer then resistance should be less.

whats your service manual say it should be 9.5kohms?

[Outdooreagle 11]

9.5-10.5 at 77 degrees 

[Goober 1,555]

21 minutes ago, Outdooreagle said:

9.5-10.5 at 77 degrees 

Okay! I can’t say that high resistance value would inhibit ignition but it’s way out of spec. Maybe you could remove it test it and see if you get a better reading. Otherwise change that puppy and try again eh?

[retro 4,048]

3 hours ago, shadetree said:

i'm guessing you mean the oil temp sensor ?, this is always grounded

 

Nope, a grounded oil temp sensor is a shorted oil temp sensor, its junk. @Melatv provided the correct specs and testing procedure.

[retro 4,048]

1 hour ago, Outdooreagle said:

The blue red ohm out at 17k ohms, however, it’s not 77degrees. I love in south ga so it’s around 60degrees when I tested it.

 

That is a high measurement but the temp is lower than 77 degrees so thats expected. For an accurate measurement the sensor should be 77 degrees F. Then if it measures over 10% higher than 10.5k Ohms OR 10% lower than 9.5k Ohhms @77 degrees F the sensor is failed is out of spec.

 

But that high measurement will have no ill effects on your CDI, since the sensor is not shorted. Keep looking....

[shadetree 5,880]

7 hours ago, retro said:

 

Nope, a grounded oil temp sensor is a shorted oil temp sensor, its junk. @Melatv provided the correct specs and testing procedure.

then why does the wiring specs show it in the wiring diagram to ground ?.

[Fishfiles 20,145]

Let me take a stab at this , the sensor is grounded when screwed into the case , at low temp ,  resistance inside the sensor doesn't allow the ground to go  thru the  sensor  , when the temperature hits the predetermined degree which the sensor is set for ,  the ground is allow to pass thru --------  so it is grounded but only after a certain temp is reached --- I have never tried it on this application but would think , if you were to take the wire off the sensor and ground it  , then the temp light should come on and that would show if there was problem with the wire or the sensor 

[shadetree 5,880]

7 minutes ago, Fishfiles said:

Let me take a stab at this , the sensor is grounded when screwed into the case , at low temp ,  resistance inside the sensor doesn't allow the ground to go  thru the  sensor  , when the temperature hits the predetermined degree which the sensor is set for ,  the ground is allow to pass thru --------  so it is grounded but only after a certain temp is reached --- I have never tried it on this application but would think , if you were to take the wire off the sensor and ground it  , then the temp light should come on and that would show if there was problem with the wire or the sensor 

now this ^^^ makes sinse to me !!. but if the sensor is bad , would this stop the c.d.i. from working ?.

[Fishfiles 20,145]

On the 3rd gen , I am not sure if a high temp reading from the sensor will stop the spark or not  , on a 2nd gen if the temp light comes on ,  the engine still runs ,  but looking at the way the 3rd gen  is wired it may , but I doubt it , remember the 98-2000 is a different animal , the alarm box is built into the CDI and that thermo sensor wire goes into the CDI and not the kill switch like on earlier generations ---- I got one 99  and it has never run hot and has the original CDI in it as far as I know ------ I know a way to find out if it cuts the spark on high temp , if I were to pull the wire off the sensor and ground that wire and see if spark disappears 

 

I don't know if the technology was around back in 99 , but todays equipment is pretty sophisticated and when a sensor is disconnected the controller knows because the signal it is looking for is not there   and will flash a code telling you  , the days of by-passing things are getting harder 

[shadetree 5,880]

5 minutes ago, Fishfiles said:

On the 3rd gen , I am not sure if a high temp reading from the sensor will stop the spark or not  , on a 2nd gen if the temp light comes on ,  the engine still runs ,  but looking at the way the 3rd gen  is wired it may , but I doubt it , remember the 98-2000 is a different animal , the alarm box is built into the CDI and that thermo sensor wire goes into the CDI and not the kill switch like on earlier generations ---- I got one 99  and it has never run hot and has the original CDI in it as far as I know ------ I know a way to find out if it cuts the spark on high temp , if I were to pull the wire off the sensor and ground that wire and see if spark disappears 

 

I don't know if the technology was around back in 99 , but todays equipment is pretty sophisticated and when a sensor is disconnected the controller knows because the signal it is looking for is not there   and will flash a code telling you  , the days of by-passing things are getting harder 

ok, but the problem he has is, he can't get spark to start with ?, so grounding the sensor in this case wont work. now..if it was already running ?, and he did ground the oil temp wire to engine, then yes, its posb it would stop firing ?, but the problem here is, he does not have spark to begin with. yes, I do know the c.d.i and alarm is all built into the main c.d.i. on this model. what I dont know is, would a bad oil temp sensor kill the engine ?. I do know for a fact, on the old school trx350's, seeing how they have a separate fan control unit box, in the case of an over heat, the fan control shuts off all power to the c.d.i. I dont know ( or remember ? ) if this is the case for his 1999 trx300fw or not ?.

[shadetree 5,880]

when all this back and forth posting comes to an end ?, I still have my money on it needs an oem c.d.i. from honda, I'll wait for the answer..lol.

[shadetree 5,880]

also, incase most missed it ?, the flywheel and stator was swapped out at one point , this very well can also be a problem for why it wont fire ?.

[Melatv 788]

Hi:  No spark -- You should go over these -- ignition coil getting over 100 volts DC (with peak voltage adapter) -- pulse sensor .4 volts min.  (with peak voltage adapter) Full charge on battery -- Exciter voltage -- good spark plug.

[Outdooreagle 11]

I told y’all we should have listened to Shadetree. 😂😂😂 new factory cdi, no firing problem SOLVED. thanks guys

[bcsman 1,381]

Thanks for posting your fix, really helps those who have been helping you out by knowing what got her going...

[jeepwm69 7,600]

Now get you a voltmeter and check your battery terminals with it running.  Make sure your voltage isn't way high from a bad regulator!  That will fry a CDI pretty quick.