wtf....not AGAIN.....need help ASAP

[ryanh250ex]

the ex has broken down twice in 3 rides....last time it was because the jets fell out of the carb, this time i dont really know what it could be.

alright here we go.

just for some background, the motor was already warm, and i had been riding for about 45 min when this happened. oh yeah, and it had been running great up to this point.

i was cruising kinda slowly in 3rd (but fast enough to be just barely in the power curve) because i was giving my sis a little ride back and forth..... i was on the throttle, and all of the sudden the rpms just started to drop.it would be the same as if you stopped giving it throttle.

i downshifted to neutral and let it coast to a stop. i had no idea what happened. i tried to fire it up again and it would barely start up. it would idle VERY slowly, and then slowly speed up some. but as soon as you gave it throttle, it would die.

i checked the gas, it was running a little low so i filled it up. tried to start it again, no difference.

i thought it could have been the jets fallen out again. when this happened last time, it would only idle if i took the airbox lid off. i took it off and it didn't change a thing, for better or for worse.

i tried to run it on reserve, no difference.

i then checked the spark plug......it was VERY black (2 rides ago the jets fell out, so that explains why) and it had some unused gas on it. also, some black crap came off the spark plug and onto the area around the hole in the head for the plug as i unscrewed it. the top part of the plug was blacker than the rest. i tried to clean it off the best i could with a beat up rag, and then stuck it back in the quad and tried to start it up. no success.

i'm embarassed to admit this........but the spark plug is 18 months old. i know i know i know, i should change it more often, i just didn't get around to it......oops.

so, whatcha guys think? spark plug needs replacing?

i need help asap, because i have a ride tomorrow at englishtown and cant ride unless i fix this.

any help would be appreciated.

[khen]

Did you put the spark plug against the head and check for a good strong blue spark?

[ryanh250ex]

how do ya do that? just take the spark plug and strike it against the head like you would with a match?

[AtvMxRider]

Originally posted by ryanh250ex
how do ya do that? just take the spark plug and strike it against the head like you would with a match?


lol no. put the plug in the plug wire and hold it up against the head. be carefull and only hold the rubber part. then try starting the quad and look at the plug. make sure there is a nice blue spark.

[redgrizz]

well the only thing i can come up with is, did u bump your choke? i dont know where the 400ex choke is so dont blame me if im wrong:blah:

[pnut420]

Originally posted by redgrizz
well the only thing i can come up with is, did u bump your choke? i dont know where the 400ex choke is so dont blame me if im wrong:blah:

Its a 250ex, 400ex's dont have reverse.

Change the plug man, even if it is getting a spark, that just means the electrical system is working right, 18 months is a long time, I went like 8 months and I thouht that was bad.

[cals400ex]

i would also check your jets again. even though your jet fell out two rides ago, i don't think the plug would still be black unless your rich on your jets. i would make sure it didn't fall out again.

[muff]

Originally posted by pnut420
Its a 250ex, 400ex's dont have reverse.


lol he said he put it on reserve not in reverse :p

put a new spark plug in her and go from there...if it runs but not really good then your jetting is off

[2004TRX450R]

The first thing to do when diognoseing a no start is to replace the plug. It is cheap and a lot of times is the cause. I don't think I would be so worried about replaceing the plug every 6 or 8 months. I have the stock plug in my '02. Granted it didn't get ridden much as it was my fianse's bike but I also have been running the same plug in my 250R for quite awhile as well. If the plug ain't fouling then don't worry about it so much. All you need to do is make sure the gap is right every so often. It does sound like you have a fouled plug though.

[ryanh250ex]

i just got back from my local dealer. i bought 2 NGK plugs, the recommended ones for the 250ex, straight out of the owner's manual.

if i bought them from a honda dealer, does that mean they are pre-gapped?

[pnut420]

[QUOTE]Originally posted by muff
[B]lol he said he put it on reserve not in reverse :p

:eek: Well its says 250ex in his name and 400ex's dont have reverse, hehe :devil:

[bdrue]

just gapit with a feeler gauge and plug that thing back in!

[muff]

Originally posted by pnut420
[QUOTE]Originally posted by muff
[B]lol he said he put it on reserve not in reverse :p

:eek: Well its says 250ex in his name and 400ex's dont have reverse, hehe :devil:

my 400 does :eek: :macho

[cals400ex]

you will still want to gap it even if it looks close to where it should be.

[2004TRX450R]

The new plug should be gaped right but you should still check it.

[ryanh250ex]

i would imagine that since it comes in a Honda box (i'm referring to the plugs), it is already pre-gapped. even if i did want to check the gapping, i have no tool to gap it with.

i'm pretty sure i'm set. tomorrow morning i will install the new plug, check the jetting, and see how it runs, if it runs at all.

[29FTEX]

You might have had some water and/or trash in your gas tank. Drain your tank and drain the bowl on the bottom of the carb. Clean out the carb for any trash, and check the air filter for leaks around the seal(trash entering areas). Check the gas cap vent tube as well, if it's clogged, it won't be able to gravity feed your fuel because of the vacuum created.

[muff]

you mean the gas tank isn't a trash can :confused: uh oh...

install that spark plug yet??

[hondafox440]

I have to ask this. How did your jets fall out?

[muff]

Originally posted by hondafox440
I have to ask this. How did your jets fall out?

yea thats a good question...even if it was loose you'd have to do like mad donuts for that to happen it seems

[ryanh250ex]

Originally posted by muff
yea thats a good question...even if it was loose you'd have to do like mad donuts for that to happen it seems

lol, i actually didnt.

i'm not sure how it "fell out", but i believe i didn't tighten down the needle jet enough the first time around. i was afraid tightening it down pretty good would damage the brass. i simply tightened it down some more when i took the carb apart again and for a few hours of riding i didn't have any problems.

[2004TRX450R]

if they are loose at all they will vibrate down and out. You don't have to be doing any wicked bad doughnuts to make them fall out

[muff]

Originally posted by 2004TRX450R
if they are loose at all they will vibrate down and out. You don't have to be doing any wicked bad doughnuts to make them fall out

lol i know i'm not stupid, I've had bolts that have vibrated loose that were tight, but if they did fall out cause he was doin crazy donuts that would have been funnier :p

[khen]

Originally posted by muff
lol i know i'm not stupid, I've had bolts that have vibrated loose that were tight, but if they did fall out cause he was doin crazy donuts that would have been funnier :p
That would be funny, but with that same logic your spark plug would have come out too. ;)

[Texan32]

Originally posted by cals400ex
i would also check your jets again. even though your jet fell out two rides ago, i don't think the plug would still be black unless your rich on your jets. i would make sure it didn't fall out again.

not necessarilary (sp). I have come to the conclusion that once a spark plug has fouled over, trash it. No matter how much time and effort you put into cleaning that pup up, they seem to magically foul out again rather quickly.

About the plug gap...when you took the plug out of the box, was there a little cardboard cylinder around the the electrode (the part that goes in the head)? If so, you shouldn't need to regap. That cylinder is what keeps the ground prong from hitting anything and messing up the gap. Either way, it doesn't take but about 30 seconds to check and regap (if needed) a plug! DO IT and sleep better knowing you checked it for sure!

oh yeah, 18 months on a plug isn't really all that bad. If you check it everynow and then to make sure the gap is still ok. your good to go....4 strokes don't need new plugs every other race...like 2 smokes!

[2004TRX450R]

Originally posted by Texan32
not necessarilary (sp). I have come to the conclusion that once a spark plug has fouled over, trash it. No matter how much time and effort you put into cleaning that pup up, they seem to magically foul out again rather quickly.

This isn't completely true. I have had very good luck with bead blasting plugs and haveing them last as long as if I put a new plug in. When you plast them it get's all the crap out even down to the base of the porciline.

Also I've been running the same plug in my ATC250R for quite awhile. It all depends on how you have it jeted. If jetting is correct you shouldn't foul plugs at all.

[hondafox440]

Originally posted by 2004TRX450R
This isn't completely true. I have had very good luck with bead blasting plugs and haveing them last as long as if I put a new plug in. When you plast them it get's all the crap out even down to the base of the porciline.

Also I've been running the same plug in my ATC250R for quite awhile. It all depends on how you have it jeted. If jetting is correct you shouldn't foul plugs at all.

Exactly. Moto magazines give the common misconception that 2 strokes foul plugs and won't idle and thats that theres nothing you can do about it. I have my 125 jetted right and I can leave it idling all day long and it won't load up on me or foul the plug.

[MOFO]

Junk that plug and buy a new one.... they are cheap...and it cant hurt to put a new one in.

FYI... if you are going to check for spark by putting the plug on the cylinder, make damn sure there is NO un burnt gas fumes from the cylinder. My buddy's brother was working on a golf cart at a golf course and checked for spark...well, the cylinder had a good bit of un burnt fumes...went up in his face and he got some nasty burns.

[2004TRX450R]

Originally posted by MOFO

FYI... if you are going to check for spark by putting the plug on the cylinder, make damn sure there is NO un burnt gas fumes from the cylinder.

Good point. Actually all you need to do is make sure you don't ground the plug so that it is in the direct line of fire for the fuel comming out of the cylender. It will continue to draw fuel/air from the carb with the plug out and cranking so there is no way to make sure there is no fumes in the cylender unless you pull the carb. Just make sure you don't stick the plug right in front of the spark plug hole and you will be fine. Also don't look into the hole while cranking. You will get a shot of fuel/air in your face or worse if it is hydro locked you will get a solid stream of fuel in your face at a pretty good rate of speed.

[cals400ex]

you may be right texan. i personally have not had any problems with a plug after i fouled it. i just cleaned it, put it back in the bike and it seemed to work great. i usually have 4 or 5 extra plugs on hand so maybe i just change them often enough not to have any problems. actually, since i have been riding, i have only had one plug give me problems. it was in my trx 300 4x4. i just couldn't get the bike started. i was coming to the conclusion the bike was just a POS, but i knew the bike was near bulletproof. i got a new plug and it worked great ever since. the wierd thing about it was, the plug i had in there was not that old. many people around here run the same plug for a couple years. this ngk was well less than a year old, but it went bad.