My 300ex sucks

[Tyler01]

I got a 97 300ex that has a crappy motor ...

1} The thing will smoke one min and next it wont?

2} it's smoking from the topend and i can't figure out why?

3} The coberator is leaking gas out of the over flow valve but the thing is i just cleaned ithe jets and everything.


I used to have a 86 250 Fourtrax which ran 100 times better and stronger. and it 11 years older.....

[wilkin250r]

Yeah, crappy little quads.

Wanna sell it? :devil:

[honda400ex2003]

it sounds like the coberator is the issue. you should be using a carburetor that would get the gas to the engine how it is supposed to be getting there.

that coberator setup sounds like it is all cobbled up lol

Sorry a bit of carb humor for you lol. why not find a new motor or get a different 300ex carb, do some valve seals, bore it out a bit to clean the cylinder up, and do a bit of maintenance on it to get it running good again. it may just need a hone and some new rings to go with your valve seals. get a new cam chain, get your valves lapped while the head is off, possibly do a bit of porting, and get it all fixed up. steve

[fearlessfred]

you two are mean, I did have a lot of respect for both of you and now im not so sure. lol

[fearlessfred]

Originally posted by Tyler01
I got a 97 300ex that has a crappy motor ...

1} The thing will smoke one min and next it wont?

2} it's smoking from the topend and i can't figure out why?

3} The coberator is leaking gas out of the over flow valve but the thing is i just cleaned ithe jets and everything.


I used to have a 86 250 Fourtrax which ran 100 times better and stronger. and it 11 years older.....
im only guessing ,that it is black colored smoke. that would mean that it is running to rich ( fuel running out of the overflow ) . if this is the case,pull the carb bowl and remove the float ,and needle valve and clean and make sure there is no debri that would keep it from sealing. reassemble the float and needle and turn fuel on .lightly lift the floats up to see if if the needle stops the gas from flowing. if it seals up then ck. the float level . hold the float bowl on the carb by hand and turn the fuel on for 30 seconds.turn the gas off and remove bowl it should be half full. put her back together and give here a try

[honda400ex2003]

Originally posted by fearlessfred
you two are mean, I did have a lot of respect for both of you and now im not so sure. lol

i gave lots of suggestions on how to fix it up and how to spell carburetor correctly. That in itself is quite useful to search the forums correctly. it wont find anything if it spelled wrong.

instead of feeling sorry for himself he should work on it a bit and get it running good.

it sounds like the 300 needs a bit of tlc and he will be good to go no matter if it jetted wrong or not. a machine that is running too rich is not going to leak gas out of the over flow either, it will give the engine too much fuel not leak it out. he would have to change jets not adjust the settings on the bowl. Adjusting the float level will however get it to quit leaking like fred said. his procedure is correct for doing that but the diagnosis of black smoke being that the float is sticking isnt. it is not rich from leaking gas out of the bowl. maybe a carb rebuild is in order too. everything stated here and by me above can be done for under 500 bucks. you could mod it out a bit more with 500 in it. a piston and bore is 200-250 depending on the bore, carb rebuild is 15, gasket kit with seals in it 50-70, new cam chain 30, hotcam 150. that would get you a fresh top end, carb rebuild, and a bit more power with the hotcam in it. that is if you have an exhaust or something already.

what mods are done? What is the jetting?

steve

[fearlessfred]

steve i was only kidding around with u and wilkin.do not take offence .as usual u gave plenty of good advise. but i do disagree on the float thing. he stated that it smokes and then it doesnt smoke.unless this is related to throttle position than it is not jetting.but we dont know that because it wasnt stated.if the over flow is partialy plugged then yes it can come out of the overflow and put extra fuel into the motor at the same time.fixing the overflow problem and checking the float level at the same time makes sence to me.he should correct what is known to be wrong first and go from there there is not enough information given to detemine that the motor needs a rebuild of sorts.
i still have great respect for your advise

[honda400ex2003]

agreed and no offense taken. :D we do need some more info to even start to pinpoint anything. at this point, it could just need some c4 in the cylinder and let er fly. BOOM! steve:eek2:

[fearlessfred]

yea i think a red power band would do the trick

[Tyler01]

btw when i say smoking from the top of the head i mean as in .

I had to put gasket sealer into one of my bolts cuz it was pumping out of it. but now its still smoking again but i dont see no oil?

And it only smokes when i rev it hard or stomp it when im riding.

Tomorrow im gonna take the carb off again and clean the jets and bowl and hopefully it will help out.

[fearlessfred]

Originally posted by Tyler01
btw when i say smoking from the top of the head i mean as in .

I had to put gasket sealer into one of my bolts cuz it was pumping out of it. but now its still smoking again but i dont see no oil?

And it only smokes when i rev it hard or stomp it when im riding.

Tomorrow im gonna take the carb off again and clean the jets and bowl and hopefully it will help out.
what color is the smoke and and are u talking about smoke coming out of the exhuast or just oil burning off the head and pipe

[Tyler01]

Its just burning oil off the top of the head and im gonna adjust my valves tomorrow cuz that why its smoking.

[fearlessfred]

okkee dokkee, good luck on that.i guess c4 could always be used at a latter date,because its gonna take more than a red powerband

[Tyler01]

yea btw its white smoke

[Tyler01]

I went and adjusted my valves and everything went back to normal. . . . I believe i over adjusted my valves the first time and that why it had a hard time running. . . . .

She runs like a charm now but u still need to get me

1}Chain+F/R Sprocket
2}Tie Rod end

and thats it. . . .

btw . . . . which chain is the better choice. They are the same chain but one is gold and the other one is metal color and how good is it to you?

1}http://www.rockymountainatvmc.com/productDetail.do?navType=type&priceRange=allPrices&navTitle=Drive&webTypeId=36&webCatId=9&brandId=allBrands&prodFamilyId=2082

2}http://www.rockymountainatvmc.com/productDetail.do?navType=type&priceRange=allPrices&navTitle=Drive&webTypeId=36&webCatId=9&brandId=allBrands&prodFamilyId=2083


Thanks Brandon

[honda400ex2003]

imo neither of them are that good. I would go with the regular x ring though since it is rated the same as the gold one. theres no point in buying the same chain just to have a gold finish on it. I like DID gold xring the best though. steve

[Pipeless416]

is the carb still leaking from the overflow? if so, take the float bowl off, then the float along with the needle that hooks on the top of the float. the hole where the needle sits most likely has some junk in it, not letting it close all the way. when i had this problem, i did the above several times, and then cleaned out my entire gas tank.

[Tyler01]

Yea its still leaking . . . i mint to clean it out again but i forgot about it but im not doing anything to it right now until i get my parts