Running real bad! Help!

[HondaRacing83]

I got something wrong with my motor or carb or something. So when im riding and im goin through gears alot it would just start spitting and sputtering and backfiring and then id go to get on the throttle and its like nothings there and then it would just spit and sputter and die. when its stone cold it wont start acting up until about 20min of riding but its not even getting that hot. it would especially do it on roads real bad, not as much in the trails as longbas it wasnt getting to hot but i still had to kinda *****foot it 2nd 3rd gear in the trails. But on roads i couldnt crack it wide open i had to baby it and nurse it on the roads. i had to keep it at low rpms at a steady throttle in 4th maybe 5th if i was lucky. that was the only way i could get it to get home as soon as you let off the throttle it just spit and sputter and backfire. it wasnt overheating i was giving it plenty of breaks to cool down. its to the point where i can barrly ride it.it cant be jetting because i got my jetting spot on last year 42 pilot 152 main on a slip on and filter. im stumped and am pissed because i can barely ride it. this makes me mad because i was looking at 450s and was gonna buy one then im like nah i dont want that kind of maintenance im gonna stick to tge trusty ol 400 then this happens and makes me lose faith. it was smoking some to when doing that

[forestbrian88]

How often do you ride it?
it sounds like a carb problem for sure....
is your Pilot Circuit runing allright?(@idle)
Is air filter cleaned? is the packing in your exhaust in good shape? these little things could change your Air flow and affect your jetting, did you check your Choke lever too? these little *******s tend to get loose and give a hard time while riding...

[#484]

Check the breather tube on the fuel cap. This happened to me. If it gets plugged up the tank can't breath and the machine will run terrible after about 15 to 20 minutes of riding. Then after it sits for a while it would run fine again. When the quad is running poorly, open the fuel cap and see if it runs any better.

[DragonGunner]

Both replies above are very good tips.....old gas not run for awhile tends to varnish up a carb. Backfiring is usually a sign of being lean. I would like to see a bigger main jet in there myself.

[HondaRacing83]

fresh gas put in that day. air filter cleaned the day before. i ride alot,maybe once a week maybe more but i baby the thing. you know now that i think about i was sittings on my cousins cr125 and he was on my 400ex and he pulled that off and tried to blow through it and couldnt hes like damn is that suppose to be like this im like idk when i put it standing up i have to vise grip so gas dont leak out hes like theres still nothing coming out of the top im like **** idk lol i just thought my carb might need cleaned

[OZ-T]

fresh gas put in that day. air filter cleaned the day before. i ride alot,maybe once a week maybe more but i baby the thing. you know now that i think about i was sittings on my cousins cr125 and he was on my 400ex and he pulled that off and tried to blow through it and couldnt hes like damn is that suppose to be like this im like idk when i put it standing up i have to vise grip so gas dont leak out hes like theres still nothing coming out of the top im like **** idk lol i just thought my carb might need cleaned
How much do you baby it? Maybe the spark plug fouled. When mine was running, I rode it almost every day since it is legal to ride them on the street here, and I baby it but I typically open it up once during every ride to clear everything out of carbon buildup. It wont hurt your quad to get on it now and then.

[HondaRacing83]

No i baby it meaning i take care of it lol i beat the piss out of it. thats the thing i couldnt open it up on the road either yesterday without it dieing. i just went and rode and it started acting up so i pulled the breather off and it helped for a little bit but then started doing it again. idk im stumped

[DragonGunner]

Poor performance at high speed....fuel flow restricted>restricted fuel tube. Restricted fuel tank breather tube. Fauty fuel valve. Clogged fuel strainer in gas tank.....if fuel fows freely check carb for clogging>carb not serviced frequently enough.

putting new gas in a carb that had old gas set for a long period of time does not clean and remove varnish from carb.

[HondaRacing83]

It has never had old gad im almost 16 i have nothing better to do i ride all the time if i know its gonna be sitting a long enough time ill shut the fuel off and run the gas outta the carb

[HondaRacing83]

Someone help i wanna go to wellsville real soon do you think my carb needs cleaned or the floats stuck or something idk

[chronicsmoke]

Someone help i wanna go to wellsville real soon do you think my carb needs cleaned or the floats stuck or something idk

so take it apart and clean it?

[HondaRacing83]

is there like a sticky on it? i dont really know my way around carbs ive only been into it once and that was like a long time ag for jetting and i dont remember a thing

[HondaRacing83]

http://i1280.photobucket.com/albums/a488/brandonsmith789/null_zps3d45ff19.jpg
it might not look it in the picture but this gold plate doesnt shut all the way or straight would this be my problem? it just barely doesnt shut straight but idk

[Stickman400]

Your choke butterfly never fully closes. If it fully shut then it would kill the engine because it couldn't get any air.

[ben300]

so take it apart and clean it?



exactly...

you need to clean the your carb really good. its not hard to do. you just take it apart. clean it of any dirt or debris from riding. blast it with carb cleaner. inspect your jets and the floats. make sure that the tube from the air filter to the carb is completely clean to. youd be surprised how dirt builds up there.

make sure your air filter is properly cleaned and is oiled properly and that your running your outerwear over the filter as well.



i rarely ever cleaned my air filter. and never oiled it. mothers day we had the sencond round of the PAXC series. the first lap i completed, quad was running great, but i got about half way through the second lap and the my quad started acting up, EXACTLY how you are drescribing yours. i barely got the qaud back ot the pits and had to quit after one lap. i took it home, took the carb off, COMPLETELY cleaned it, COMPLETELY cleaned and oiled the air filter, checked my valve adjustment, and COMPLETELY cleaned the air box through out. thing runs fantastic now. no spurts and sputters at all. took it down to the mountaineer GNCC, and took 4th in my class with it.

everything in the carb, especially with a four stroke, has GOT to be clean.

[HondaRacing83]

Just a couple days before i went riding saturday i tore my airbox and intake tube out and cleaned them completely and cleaned my filter and oiled it. im pretty good with cleaning and oiling my filter but it is 8 year olds and the carbs never been cleaned. just adjusted my valves last fall so im guessing its the carb. i went to take it off last and was going to take the side cover off to take the throttle cable out and those screws are really soft i wasnt thinking and was in a hurry and really boogered up the head of a screw abd idk what to do about it now. Id like to have it running by saturday because i wanna go to the gravel pits with my buddys

[HondaRacing83]

Just tore my carb apart. Virtually spotless. Very clean. Now whats the next possibility it could be?

[chronicsmoke]

Just tore my carb apart. Virtually spotless. Very clean. Now whats the next possibility it could be?

did you take all of the jets out and blow them out with compressed air?

Have you tried running it again?

[01boneless]

sounds like needle clip fell off to me.

[HondaRacing83]

Yup i took all the jets out, float owl, float, i mean i tore it all apart. Yeah i put it back together last night after i cleaned the carb *no leftover parts, theres a success itself lol* but it runs but i only ran it up and down the driveway a few times to made sure it still ran after i tore it all apart. It spit and sputtered a little but i wont know for sure till this weekend when i go riding. i blew the whole carb out with compressed air i cleaned it, it was very clean. nothing significant stood out to me while doing it so im assuming thats not the issue and problem not fixed

[forestbrian88]

you just need to set it correctly i think

[HondaRacing83]

you just need to set it correctly i think
what do you mean?

[DragonGunner]

If you tore it apart and cleaned everything did you set the air mixture screw back right...how many turns out from all the way in..? try adjusting it a littl at a time....also try a new spark plug if you haven't already and let us know.

[HondaRacing83]

i didnt touch the air mixture screw, would that be the reason it ran weird because it wasnt set right?

[KKiowaTJ]

You have to tune them for seasons from time to time. The a/f screw should be around 2-2.5 turns out.

Did you by chance leave you gas on and in ran into the oil? Have you changed it since? That and draining the gas out and putting in fresh gas never hurts and is easy to do. Is it getting the fuel or starving for it?
What size jets and what notch is the clip/needle?

[HondaRacing83]

152 main 42 pilot. idek what the needles at pretty sure it was never moved from stock

[KKiowaTJ]

IMO id put a bigger main in it and start with 2-2.5 turns out. A plug wouldn't hurt, But sounds like you just need to tune it or bump the main up and tune.

[KKiowaTJ]

I read the OP. If its dialed in and everything is clean id look into the coil and see if its loosing when it gets warmed up. Look at the electrical side since its clean and dialed in with your mod's, R/R coil etc. I put D-grease on damn near all connections and imo the butt dyno noticed some response.

[DragonGunner]

i didnt touch the air mixture screw, would that be the reason it ran weird because it wasnt set right?


Yes....heres the problem, you didn't take the air mixture screw out and carb clean it, it can get dirty and varnished up in there just like the jets and everything else....yet you claimed you tore it ALL down and cleaned everything. I'm not saying thats your problem but its getting more difficult knowing what has been really done an hasn't been done. I have a 400EX that wouldn't run right, checked the spark on the plug and it was making spark ok.....still didn't run right, did everything else and then remembered my Dad telling me yrs ago a plug can show spark and still be weak or bad.....got a new plug......ran like brand new.

[HondaRacing83]

Like i said carbs arent my expertise i hate them and tore it down as best as i could to my knowledge. I dont even know what screws the air mixture screw

[KKiowaTJ]

Like i said carbs arent my expertise i hate them and tore it down as best as i could to my knowledge. I dont even know what screws the air mixture screw


Just go to youtube and type in 400ex carb clean and set. It will give you many options, Plus it don't have to be a Honda, Most carbs are the same. The a/f is the middle top/bottom is bowl but a vid will help and save you $$.

That's what I did when I had to install a new bearing carrier, Watched the vid a few times to know what to lube, How to assemble etc and im 100% problem free. I did the same on my pit bike carb, Watched vid until it was automatic on 'what to do'/'steps to take' until finished. Good luck either way

[DragonGunner]

Been there like you....best advise is to get a Manual.....my riding buddie always think I'm good at trouble shooting, they ask for help about their 250r and Banshees......I ask what the thier manual says how to do it....they look so confused.....a few bucks for a manual and even bonehead me was even able to tear down a 400EX transmission to the bone and put it back together....and it still working 7 yrs. later!!! I'll say it again....."Manual."

[HondaRacing83]

I think i have the little book up in my room that comes with it when you buy it but i dont have a service manual if thats what you mean i think