bogging and backfire

[dan42684]

i own a 05 z400, jetted, and a slip on white brothers exhaust. and im having some problems.

#1 if i leave it outdoors overnight and try to ride the next day it will take forever to start and backfire while tring to start.

#2 when it is finally started and im riding if i accelerate hard and try to go fast it will bogg to the point of almost stalling or it will stall.and it also backfires while im riding.

#3 it wont stay at idle unless i turn up the idle real high.

can anybody please give me some info of what might be going on. thanks

[jonboy]

First things first, check your gas cap vent, if it is plugged it could cause fuel starvation. Also check the gas,it could have gone bad or moisture got into it. Have you done a plug check yet?

[dan42684]

yes i checked the plug it was a lil dirty but nothing serious so i cleaned it up i also drained the gas and changed it i always use 93 octane.and i just checked the cap and hose and its not clogged.

[smoothie]

are you running it with the air box lid on? sounds like thats your problem. what do you have in there for a main jet?

[dan42684]

the lids been on since i got it and it never had problems before. it just started like 2 months ago. i got it used in like august 06. idk what kind of jets are in it. this is my first quad, i used to have dirtbikes so im new to these.

[smoothie]

oh i see, so you bought the quad with the pipe on it and stuff.. gotcha. quads are basically just like a dirt bike, when talking about the engine. You might want to just take the carb apart and clean it. that isn't a bad idea weather it is giving you problems or not. I'm almost 100% positive that your having a fuel delivery problem. I say this because it needs a high idle... well your idle adjustment only adjusts the carb not the ignition. that and you also said the plug looks fine which says it's burning the fuel properly. could be some grime down by the pet cock filter or something too.

do you know of any work that has been done with the timing chain, tightening it or anything like that? if your chain is loose enough it will throw the timing off just enough to make the engine run like poop.

[dan42684]

i just took apart the carb and everything looked like new nothing looked dirty. i also took the gas hose off that runs from the tank to the carb and replaced it with a clear one. and when i turned the gas to prime i was able to see the gas runinng through the hose it was running through the hose realy slow and then stopped and the hose wasnt even filled. so i took the pieace off the bottom of the tank (the one with the prime gas res. switch) dont know what its called, blew it out with a air hose and made sure it wasnt clogged and put it back on. then i tried running the gas through again and it still ran through realy slow. so i started it up. it started fine because it was in my warm garage. took it outside and let it idle for a bit. hit the throttle and it popped, sputterd and bogged. i let it idle some more. and i noticed the exhaust pipe was red hot like real red. i dont know whats going on with this thing. i would just take it to a shop but im afraid of how much this is gonna cost and i'd rather fix it myself to save money

[Titanium]

try running it on prime. my quad does this too but when i run it on prime it runs fine.

[dan42684]

i tried that it ran a lil better, but still ran bad.

[jonboy]

If your pipe is glowing red at idle, it sounds as if it is running way too lean.

[dan42684]

how do i fixit from running lean? and would that cause it to bogg and backfire?

[smoothie]

thats what i was going to say... it's running way lean. especially since you can see that the fuel flow is slow. not getting enough fuel and therefor running lean. the thing your talking about is called a petcock, ya weird name lol. I would try cleaning out the filter and stuff that is in the tank(when you pull out the petcock it will be right there on top of it) if that doesn't help try getting a new one. that is what is giving you problems.

[dan42684]

i found the problem. it was the petcock valve, i took it apart and found a rip in the diaphram. thanks for all the help

[huffranger4x4]

with any aftermarket exhaust/slip on you still need to pull the carb and see what main is in it....also take off the airbox lid you'll see a big difference....you also might want to richen the air/fuel screw by 1/4 or so increments...