"ATV Smart" people only!!!!!

[Blaster250x]

Ok,I have gotten so many different opions on what is wrong with my quad. I need someone who knows alot about this stuff to answer my question. It is a 250x with a 350x motor in it. It runs real bad. It won't start by kicking it,you have to pull start it behind another quad. When it starts,it pops and cracks and runs real rough,and if you let it idle for a while it will die. It goes real slow when it does run and has no power,and when the throttle is at 1/2 way in,if you push it in all the way so it is hammered,it wont accelerate,it stays at about the same speed as when it was at 1/2 throttle. I changed the jetting,put in fresh gas,took off the muffler,and nothing worked. I don't know what is wrong with it. I thought it might need to be rebuilt but it has good compression. Some one says it needs to be timed or the valves need ajustment. The de-compression cable is broken,so I held it open with a hose clamp for easier starting,and when i took it off,it seemed like it became easier to start. I weigh 115 puonds and i am 5'11 and i am pretty weak,and i can kick it over pretty easy. You think i screwed up the mechanism in the decompression? please help!

[DEAL]

Its either your carb or wiring. Take the carb off and make sure you have a steady stream on gas coming out when you hit the throttle.
Make sure all your grounds are good for your wiring. Change your spark plug. If that doesn't do anything make sure you have spark coming from the spark plug boot.
If you have weak spark coming from that you most likley have a wiring problem.

[redzoomer]

This may be a long shot but it sounds as if your carb. or gas line has a blockage.. Check both to make sure it isn't stopped up. I had an 87 250X with a 350X motor years ago....boy it was quick!

[96300ex]

Sounds like somethings screwy in your carb... I cast my vote for something with the choke seein' how it wont start unless pulled...

pull your plug out and see if it's got oil on it or if it's a glossy black... if so you've been running around with your choke on or you're running real rich... if it's white then you're running lean

Also, one time i had my filter off to clean it and K&N says you have to let it dry naturally before your oil it so i stuffed a rag in the air intake tube and left it sit. My dad started it up to move it adn i couldn't figure out why it wouldn't run for the next few days. then it hit me, there's a rag in the carb:eek: ! stupid stuff like that can cause tons of frustration, check it out...

[Wingnut]

I have no idea what your carb's design is, so this is a REAL long shot. Make sure the slide is moving. Some screws inside my carb vibrated loose one time and your description sounds like what my 400 was doing. Just pull back the airbox boot and push (twist) the throttle to see if the slide moves, and go from there.

[phatswinn]

i have the exact same problem with my friends quad and im stumped too!! :confused: :confused:

[Blaster250x]

Well,the plug is real black when I take it out,i put a new one in,started it,and when I took it out it was completely black,like someone dipped it in a bocket pf flat black paintt,it isnt glossy.

If i was you, I would take my carb off and clean it. Make sure everything is working alright in it.

[96300ex]

Carbon on the plug? is it dry or wet? Are you sure you haven't been running around with the choke on?

[nakomis0]

It could be any number of problems with the carb.
I would take the carb off, take it apart and spray it with carb cleaner.
Fix the jetting, you have it jetted very rich (assuming the carb is good, and working correctly) Get a smaller main jet in there. What size main jet do you have?
Does anyone on here know what a good main jet size would be for his set-up?

If I was to take a guess, about the main jet size, I would probably say a 152 main. Heh, even though I have never worked on a 350x, Just 400exs, Blasters and Banshees.:rolleyes:

[BANSHEEadam]

I had a pretty similar problem with my 300ex..the CDI was all messed up, and now my banshee too. Not sure if it's "CDI" on a 350x, but the black ignition, control box, thingy, whatever the name of it is, sounds to be your problem. Should be on the frame under the front end, somewheres between the engine and a-arms. You can pick up a used one pretty cheap too..

[Blaster250x]

I am running a 135 main in there now,but i will make sure the choke is off,and if that doesnt work ill try to get a new black box...

[honda400zx]

id say just rejet and go from there i dont no how the cdi would effect that because the cdi is part of the electrical system:confused:

[BIGRED400]

It may not be getting enough air and too much gas for your motor and maybe that is why it is running too rich and your plug is fouled , sometimes a lil "plug reading" will help you out ,hope that helps, I was using too much air filter oil and was having problems with my plug getting black and rich.Hope that helps