300ex problems please help?

[bigbob]

I have a 1993 300ex that is having problems. When you hold the throttle open it pulses. What I mean by that is it will rev for a second and then cut out. In my opinion I think it is a cdi box? Has anyone had this problem before? It doesnt sound like it is carb related at all. Thanks for the input.:D

[bradley300]

i'm almost postive you have water in the gas tank, drain the tank, clean the carb and i bet it will run great;)

[bigbob]

I would normally agree except the tank has been drained. The carb has been cleaned out as well. Just wondering could it have something to do with float adjustment maybe?

[plkmonster2]

The float level may be too low, and may not open enough. Also, make sure to clean out the fuel passage. If it can't open enough, it will use up all the fuel, before it can be replaced. Also, make sure you petcock is supplying a healthy flow to the carb. Take off the hose, and swith it to open, then reserve. It should come out fairly fast. And, make sure the hose isn't clogged either.

[bradley300]

Originally posted by bigbob
I would normally agree except the tank has been drained. The carb has been cleaned out as well. Just wondering could it have something to do with float adjustment maybe?

yeah, thats possible.

if the tak has been drained, it could also be your cdi as you mentioned

[ghak99]

Ok, the 250x/ 300ex for some reason will show the symptoms you described when the stator is going bad. I have seen it twice and heard of it atleast 4 more times from other people. I now have a spare stator just in case it happens again. If you run out of ideas find a good used stator and pickup and swap them out.

[efilnicafesin]

I've got the same problem with my 250x going on right now.... Is there a way to test the stator or just replace it?

[ghak99]

Originally posted by efilnicafesin
I've got the same problem with my 250x going on right now.... Is there a way to test the stator or just replace it?

This is a very common problem with the x, Sorry I don't know if they can be checked or not. I simply borrowed one from a friend the first time it happened, and shortly after bought a used one for a spare in case mine went bad.

[Bill Fuller]

Have you checked to see if the jetting is OK?Sounds like it's off at the main jet.Your sure it's not the rev limiter?Try it with out the air box lid,better or worse?

[bigbob]

I just changed out the stator and that was not the problem. While pulling the bike apart I discovered a couple of things. First off the oil had alot of fuel in it. I think that could have something to do with maybe a weak spark maybe. I also looked at the jets in the carb 122 main 40 pilot. The bike has a fmf mega max silencer and a k&n filter. I live in ky. so elevation is 100 or under I believe. I still believe the engine could not be firing right due to the pulsing of the throttle and the fuel in the gas. PLEASE HELP!!!!!!!!! I have no idea what this bike should be jetted at. Not real familiar with a honda.:confused:

[Quad Dude]

had u had ur engine apart right befor this happened???

[JDiablo]

Originally posted by ghak99
This is a very common problem with the x, Sorry I don't know if they can be checked or not. I simply borrowed one from a friend the first time it happened, and shortly after bought a used one for a spare in case mine went bad.

there is a way to check actually,forgot wat it is called though

[Snow]

i got this same "pulsing" when my jetting was off so i bet thats what it is.

[efilnicafesin]

Originally posted by 300exrida
there is a way to check actually,forgot wat it is called though

You're prolly thinking about a resistance check with an ohmmeter... :confused:

I had the same symptoms, and I found out what my problem was... :o ... I discovered that one of my adjusting studs on one intake valve had completely backed out... I found it wedged next to the timing chain adjuster.... :grr: I was planning on doing a rebuild anyway last weekend, so it wasn't a big deal for me.... What a difference it makes having all four valves working on a good cam :D

[JDiablo]

no the stupid honda guy said there is a way,but yea your prolly right there isnt:rolleyes:

[bigbob]

I did have the engine apart right before this started happening. Had to tear it down and rebuild. It was already bored before so we had to go to 80 over. Any ideas ?

[efilnicafesin]

Has it worked since putting it back together? Maybe valve timing or adjustment?

[bigbob]

The problem started right after the rebuild and has slowly got worse. Anyone else have any answers? I am going to check my valve adjustment after that I am out of ideas. If that dont fix it I am going to take it to the stealership!!!! Dont want to do that so please help.:confused:

[bigbob]

Checked all the valve clearences everything is good. WHAT IS GOING ON HERE I THOUGHT THIS WAS A HONDA SITE? NOBODY HAS ANY IDEAS???????????:(

[fastexgirl4c]

mine did the same thing.. then i put a hiperformace cdi box.and i didnt have anymore troubles wit it.. does it break up when ur in full throttle?

[bigbob]

It starts to break up at about 3/4 throttle. I guess Ill try the cdi box next.

[redrunner]

Originally posted by bigbob
WHAT IS GOING ON HERE I THOUGHT THIS WAS A HONDA SITE? NOBODY HAS ANY IDEAS???????????:(

You have gotten several opinons, be patient. You will get some more when the week starts, alot of folks are out riding.
it does sound like a cdi or carb issue. have you taken the carb of and cleaned it? check you needle postion, you may need to bump it up a notch.

[bigbob]

I just took the carb off and cleaned I adjusted the clip so it would run leaner. I am guessing it is running to rich and that is why I have gas in the oil? Sorry for being impatient Im getting frustrated with this damn thing.

[redrunner]

Gas in the oil! right after a rebuild, what about the piston/ring install any possible issues there?
Again there are many possible solutions that is why it is tough to give "the" answer here but keep trying. Have the fun is fixing these things ain't it?:D

[bigbob]

I dont think that there is a problem with the install. I have very good compression. If the rings were collapsed I dont think I would have much compression at all. Correct me if I am wrong but if the engine was not firing everytime it should the gas would just keep loading up in the cylinder. Does this sound right?

[redrunner]

That sound right, I am no expert for ya though. If the cdi doesn't get it we will need the big guns like cals400ex for a better answer.

[Quad Dude]

i have a real good idea what ur problem is because it seems to be having the exact same things happening to it as mine did after my rebuild. and if u were to ask me id put every dime i own on that ur timeing is off because thats what mine did and no matter how u adjust the valves or jet the carb it will never help.

ps on the flywheel theres three marks two little lines (ll) an side ways F and a line and then theres the side ways T with a line to set it at TDC set it at the T but u must past the other two marks before reaching the T and make sure ur on the compression stroke you will be able to feel it while turning or you can take your spark plug out and put ur finger over the hole until you feel air push past your finger. and when your done setting it at TDC adjust your cam accordingly. then put every thing back together.


GOOD LUCK

josh

[bigbob]

DING DING DING!!!!! QUAD DUDE IS THE WINNER!!!!!!! Sure enough the timing was off one tooth. Not sure how I managed to do that. Must have had too many budweisers that night.:D Thanks for all the help!!!!!!!!

[redrunner]

;)

[efilnicafesin]

Originally posted by efilnicafesin
Has it worked since putting it back together? Maybe valve timing or adjustment?


Originally posted by bigbog
DING DING DING!!!!! QUAD DUDE IS THE WINNER!!!!!!! Sure enough the timing was off one tooth. Not sure how I managed to do that. Must have had too many budweisers that night. Thanks for all the help!!!!!!!!

The valve timing was suggested a few days ago.... :blah:

glad you got it running!

[Quad Dude]

HURRAY GRATZ FOR GETTING IT RUNNING!!!!!!!!!!!
wish i would have know bout this website when i had my problems because it took me forever to find out what was wrong

PS what do i win. i could use one of those new 450s