Not sure where to post this

[layt 0]

So I have an early nineties 300 fourtrax 4wd.  It ran great until it didn't one day.  It just died.  I waited a while went back and kicked it and it cranked right up.  Well it happened again and no such luck. No fire and no neutral light.  I ended up pulling the safety neutral and it was dry rotted and shorted between all wires. I fixed that and ordered a new cdi and put another coil.  Now the bike runs but it hits line there's a dc voltage trying to push an ac load.  It won't take the gas but it doesn't at all seem fuel related but electrical somehow.  Can't find anything on this issue. Anybody been here before? I wish I could load an audio file

[Fishfiles 20,145]

Hi , welcome to the forum >>>300s are good 

 

What are you referring to as the " safety neutral " ?  >>>

 

Did you use a Honda CDI and coil or aftermarket ? >>>

 

 Did you clean the carb and looked at the diaphragm ? 

 

Did you try a new spark plug ? 

 

What does this mean " Now the bike runs but it hits line there's a dc voltage trying to push an ac load. " 

[layt 0]

 

Carb is good.  Safety neutral I mean the wires going into the bottom of the block that lets you start it only in neutral.  I have not made it to a spark plug yet. At least not a new one.  Aftermarket.  If you e ever tried to run an ac appliance on na dc load you'd see that it only hits like once a second as opposed to being fully powered.  That's what it's doing.  It's not that it's bogging down it's that it's missing but not in a bad plug type of way but a way I've never experienced like it's electrical  it doesn't pop and backfire it just like skips and won't take gas.  Getting plenty it just won't allow it to rev up

[layt 0]

Hoping for plug but I'll let you know later today

[shadetree 5,869]

is this '' new '' c.d.i. aftermarket ( china ) ?, or oem ?, china c.d.i.'s are junk. is carb clean ?..has it been sitting for awhile ?. is fuel reaching carb from tank ?, is the vent knob on top of tank in the '' on '' position ?. have you tested the compression?, most 300's require a min of 100 p.s.i. to run decent.

[Fishfiles 20,145]

51 minutes ago, layt said:

 

Carb is good.  Safety neutral I mean the wires going into the bottom of the block that lets you start it only in neutral.  I have not made it to a spark plug yet. At least not a new one.  Aftermarket.  If you e ever tried to run an ac appliance on na dc load you'd see that it only hits like once a second as opposed to being fully powered.  That's what it's doing.  It's not that it's bogging down it's that it's missing but not in a bad plug type of way but a way I've never experienced like it's electrical  it doesn't pop and backfire it just like skips and won't take gas.  Getting plenty it just won't allow it to rev up

Ok , then your  ac  statement you made  might make sense , from what I have read on the old 350s , the 350A was a AC electrical system , the 350D was a DC electrical system , being you say you used after market CDI ^^^^ , then you might have the wrong CDI ---- we need to figure which one you have , a A or D ---- some parts I have read that won't interchange between the 350A and 350D  is the CDI , voltage regulator  , the starter gears and a few other parts , someone will be along that knows  more about the difference between the A and D 

[layt 0]

Getting good gas.new cdi aftermarket.  I thought that it might be accdi so I made sure to order a dc aftermarket and it won't fire at all I have not officially tested the compression shade tree but it'll break your leg without the compression release.  Oh yes. Also. I have continuity between my plug wire and my frame.  That shouldn't be should it

[layt 0]

It's like a 92

[layt 0]

The old cdijust had the brand onit I believe.  I looked but don't recall any numbers

[layt 0]

There was one more thing about that cdi that I forgot. The four prong and two pro g plug are on opposite side on new one.  Could one of those wires being on the wrong pin cause that kinda symptom or would it just not run

[shadetree 5,869]

19 minutes ago, layt said:

There was one more thing about that cdi that I forgot. The four prong and two pro g plug are on opposite side on new one.  Could one of those wires being on the wrong pin cause that kinda symptom or would it just not run

tells me..you got a china c.d.i. they are junk. you are better off locating a used oem for that year/make/model.

[shadetree 5,869]

59 minutes ago, layt said:

Getting good gas.new cdi aftermarket.  I thought that it might be accdi so I made sure to order a dc aftermarket and it won't fire at all I have not officially tested the compression shade tree but it'll break your leg without the compression release.  Oh yes. Also. I have continuity between my plug wire and my frame.  That shouldn't be should it

compression sounds good to me. keep in mind, these models have a ele fuel pump, if the pump is weak ?, it also wont run good. my money is on the china c.d.i. you got. chances are, the seller you got it from '' claims '' this c.d.i. will work on all trx350's ?..no..they will not !.

[Fishfiles 20,145]

I was  confusing your 300 post with a 350 post 

[layt 0]

Plug didn't help

[Fishfiles 20,145]

Do you know about unscrewing the wire from the spark plug boot , cutting 1/4 inch off the end of the wire and rescrewing the wire into the cap --- sometimes there is a bad connection  -------    did you happen to disconnect the battery lately ad maybe reconnected a wire in the wrong place 

[layt 0]

Has no battery. And yes I've done that too.  

[Fishfiles 20,145]

Many have warned over and over that running your Atv with no battery will fry the stator.  

[layt 0]

I'd rather have the electric start but when I got it the battery compartment was in bad shape.  Alot of rust some of the previous owners handywirk.   Could this be a symptom of timing at all?

[shadetree 5,869]

On 10/29/2023 at 10:07 PM, layt said:

I'd rather have the electric start but when I got it the battery compartment was in bad shape.  Alot of rust some of the previous owners handywirk.   Could this be a symptom of timing at all?

even if the timing was off ?, you should still get spark at the spark plug.

[layt 0]

It runs. It just won't rev up. It's like it's hitting a rev limiter

[shadetree 5,869]

3 minutes ago, layt said:

It runs. It just won't rev up. It's like it's hitting a rev limiter

ok. most times this is a fuel issue ?, or a c.d.i issue ?.

[layt 0]

To me it definitely sounds electrical so I was leaning towards cdi.  I cleaned carb and everything is in order with it.  This is like a hard wall where it cannot rev up.  I am going to order an oem cdi because it at least will crank with the new cdi so that tells me the old one had to be bad.

[toodeep 1,758]

I've had great luck with ricks motorsports electronics CDI unit's, if you want an aftermarket. I personally use them and use them on other peoples machines.

 

I would clean up the wiring back in the battery box. If you have corrosion going on with one of the connectors (regulator, main fuse) it is going to mess with you. You can also take the original CDI (confirming there is no spark at the plug with it) and smack it against the bench. Most of the time that will make them work for a short while. There is also a baking process that can be done to try to make it work again.

 

Again though, if your wiring is a mess... fix it. Especially since your thinking electrical issues. The 300 is pretty simple and there isn't a lot of wiring so you might as well make sure it's 100%.