300ex troubles

[josh79z28]

I have a 1997 300ex It will run if you push start it but will not fire up if you use the starter. what could it be ? Also it has a full curits sparks pipe what size jet kit should I use with it ? Any help at all would help.




thanks .......josh

[justen08]

What does it do when you try to fire it up?It could be your battery,or starter.Get a tester and test your battery and go from there thats what i would try.As far as jets go im not to good at jetting.Hope ths helps.


Justen

[josh79z28]

Its like it is not fireing at all,I have had the coil tested it is good and the battery is good also. It cuts out and pops and cracks when it does run also gets very hot.



thanks ......josh

[justen08]

I dunno what it could be maybe try to clean your carb. Wish i could help out more man.


Justen

[josh79z28]

carb is clean .Its got me stumped:cuss: :cuss: :cuss:

[Imbroke]

make sure its in nuetral mine doesnt start unless its in nuetral unless you meen it is trying to start and it just wont then i dont no what to tell you

[josh79z28]

I have it in nuetral it just wont start

[josh79z28]

now it dont want to start if you push it what can it be??? plz help

[Tommy Warren]

check the coil/spark plug then if they work fine i'm gonna say its your jetting maybe trya larger pilot jet. put a size 40 pilot and a 126-128 main jet and see if thet works.

[josh79z28]

coil and spark plug is good i try the other thanks

[josh79z28]

what would make it not fire? it rolls over but no spark could it be cdi box?

[John451]

If you have a continuity tester unplug the 2 wires going into the back of the coil and put the positive in one and the neg. in the other and that'll tell you if its the CDI if it's not the coil. If you get a reading over 1 volt or any amperage then it's the coil, if you get nothing its the wiring or cdi.

[josh79z28]

i will try that thanks

[ochsclewis]

did u get ur stator tested thats what went bad in my 250x which is the same thing as a 300ex exept its kick start

[John451]

how do you get it tested? or where?

[ochsclewis]

just take it to an atv dealership they should test it for u idk how much it cost but its worth a shot

[John451]

oo aight.. i'm stilll thinking mine's a wiring or cdi problem because it ran, sat for a week, then I took the side cover off to see how the clutch was, then put it back on and put a new starter in. The starter cranks over so i dont think its the reverse or neutral indicators but i'm going to ground those out just to be safe then get rid of the light box becausue the last guy took the lights, ignition, and basically everything else that didn't have to do with the ignition and just twisted the wires up. The quad stopped working for a while during the day while i was rididng but i just picked the front up and dropped it and it was fine.

[ochsclewis]

yea u never know just trial run thats what i did with mine.

[josh79z28]

i tested my stator it is good

[josh79z28]

i think it is the cdi box because it rolls over but no spark and it ran fine

[ochsclewis]

alright well best of luck fixing it.

[josh79z28]

ok it ran fine wine i got it the person i got it from took the lights off and the key switch off he was sat up for mx but i dont ride mx i ride in the woods

[John451]

Originally posted by josh79z28
ok it ran fine wine i got it the person i got it from took the lights off and the key switch off he was sat up for mx but i dont ride mx i ride in the woods

LOL same here, except for the woods one, I stunt ALOT and I love mx.. But when he cut alll the stuff off he just stripped and twisted the wires together without tape so i think it grounded out and blew my CDI, when i first put the starter on and plugged the battery in it started cranking over because one of the starter wires was touching the frame lol. I'm just gona borrow my friend's CDI and try it.

[josh79z28]

good luck i think it is the cdi because wine it gets hot it breaks down it starts spiting and spuder

[John451]

Nice, i just put my cdi on my friends 300 and it started up which sucks cuz I wanted to upgrade and cuz its the easiest thing to fix. But im thinkin its the wiring...

[josh79z28]

i got the cdi today and that fixed the problem but my 4 wheeler still spits and spuders at half open and it backfires to what could this be? it's got a full curtis sparks pipe and uni airfilter do you think it is the jet's? i need help plz

[John451]

Well, it could be the jetting but your cam chain may have skipped a tooth or the reverse indicator could be messed up. Is it making noises like when you put it in reverse? Now that i think about it though, its problably not the cam chain because it sounds like it idles..

[baker420ex]

have you checked your plug in awhile? run it and then take it out see if it smells like gas...may be fouled up...or you could have water in your gas. other than that sounds like you need to jet your carburetor appropriately for your bolt ons...you could put your stock muffler back on and see if that fixes the problem. you need to check the basics before you can pinpoint ur problem man.

[josh79z28]

cam chain is fine i check it today and it's not making no sound wine i put it in reverse and i don't have the stock pipe i got it that way its fixed know it was the switch i cut it off know it don't have no spiting and spuder and i do need jet's there stock

[John451]

So it was the reverse switch? and if it's not bogging or breaking up or making the plug white i'd say your jetting is fine.

[josh79z28]

it is not the reverse switch it is not bogging or breaking up it was the switch to start the bike some one mest it up and started puting wires together and that is why i cut the switch off.it is fine now but wine i go to give it gas it sometimes don't what to take the gas what could this be? thanks josh

[John451]

sounds like your main jet is too big and it's bogging. try taking your airbox lid off and see if that helps it at all. Also make sure your choke is off.

[josh79z28]

ok what does the main jet look like?

[John451]

main jet... did you try without the airbox lid?

[josh79z28]

ok i will take the carb off this week i am going to a atv race with a friend this sunday so i dont have the time thanks

[kd450r]

You shouldn,t have to take your carb off. There should be a cap on the bottom of the carb and with a 6mm socket you should be able to get the jet out. You need to verify lean or rich before doing anything though. Lean is a white electrode on your spark plug, rich is a black electrode and brown is perfect.

[John451]

Yeah, sounds too rich to me, ya know? You can only swallow so much like the quad, he said it wouldnt take the gas aka bogging aka more gas than it wants.

[josh79z28]

i have a problem it is poping back thru the carb and pipe and it is not wanting to take the gas what could this be need help? asap

[josh79z28]

the pipe gets hot in a instant as soon as you start it up what could this be?

[John451]

Originally posted by josh79z28
i have a problem it is poping back thru the carb and pipe and it is not wanting to take the gas what could this be need help? asap

Either your exhaust is plugged up or your exhaust valve is stuck shut due to the camshaft or broken spring.. Start by taking the exhaust off and start it then if it still does it take the 2 valve caps off and look in, your rocker's rod could be broken then take the whole valve cover off and check to see if the cam is damaged then push down on each valve if you haven't found the problem yet. If it is the valves they will not go down.

[John451]

ohh... hahh jk it's problably your intake valve is stuck open.. so it sucks the gas in then it ignites it with to much oxygen so it burns really lean and overheats the exhaust and some exhaust goes out the carb. So start with the valves..

[josh79z28]

will do thanks