i got it yesterday.. rode it for a while. first thing i noticed the header was glowing red all night. (didnt start riding till 7pm and was already dark) is this normal or bad? cause i rode for 3-4 hours. my buddy said it was fine. im not so sure though.


also...it will not idle properly. tried adjusting the idle screw and it will go from running on teh verge of cutting out to revving real high at idle. and when i push the throttle itwill cut out if i dont do it slowly. thanks for the help

 

Sounds like a jetting problem to me.

 

sucks...i got rid of my truck and got a car. now i bought a ATV and need a truck againa nd dont have one right now. had to have someone pick it up for me. now i gotta have someone take it to get fixed. you'd think the dealer would have it ride ready when you buy something like this.


gonna ask if the header is supposed to glow red also

 

Well, it is hard to tell if the quad is running lean from looking at the header. With the new thin wall stainless headpipes, they pretty much always have a red glow to them in the dark. As for the poor idle, do a few things before looking at the jetting. First, clean and oil your filter. Next, check for any compromise in the intake tract, i.e. loose fittings, holes, or cracks. If you don't see anything, then try spraying starting fluid on the intake from just after the filter right up to the motor. If the motor begins to race, then you have an intake leak to fix. Also check your exhaust for leaks, make sure the header is secure to the exhaust manifold as a leak here will also cause the quad to run lean. If all this checks out, then it is time to mess with jetting. What does your plug look like? I think the first thing to do if it is lean would be to return the fuel mix screw to 2 turns out, and then up the pilot a few sizes. Changing the needle clip may help also(go further down the needle with the clip)

Good Luck!

 

ill checkall that tomorrow when its light. are there usually jetting problems from the factory? and by fuel mix screw do you mean the idle screw that you turn with your fingers? the pilot is insidethe carb right...do you know where there is a schematic of our carb online? so i can see the inside of the carb and how it works. only my second ATV .f rist was a blaster and i never messed with it mechanically.

 

also..did i get screwed? 2007 YFZ 450 for 6600$. still have to pay sales tax at the DMV too at 5.75% i think

 

That is a good price, around here they are going for $7300 roughly plus taxes. As far as it running, every YFZ I've been around has done the shut off thing if given too much throttle from idle and I have been told this is a 450 thing.

 

ok your yfz from the factory normally comes jetted a little lean, go down a size our to on the main jet. if you need help with jetting on yfzcentral.com click on the tab "tech" at the top, there is a complete jetting guide with pictures of how to do it! no matter what your jetting is your pipe is going to get red at night, your exhaust is hot, it will always be hot.. for your idle issue, how cold is it where you are?? its not going to idle very well in the cold till it gets warmed up, also you need to rejet when it gets cold out, your dealer isn't going to rejet the quad for you before you buy it, at least no dealer i have ever seen will.. if you have a garage try pulling it into the garage and let it warm up in there and then see how it idles...

 

Hold on, this thing is brand new? I would still check for leaks and such, the irratic idle is problematic. If you really get on the throttle hard(most evident at idle) the quad will bog and maybe even stall. This is due to a poor design in the FCR carb, and pretty much any motor running this carb does it. The solution is to install a new fuel pump cover, Boyeson has the original, but there are others out more reasonably priced now. Note that this is not much of an issue while riding, because who rides at idle speed and then tries to go right to WOT?

 

its below freezing where im at now. it actually doesnt start acting up until it gets warmed up. i cranked it right up yesterday and it idled for a few minutes then when i started feeling heat from the pipe it cut out and wouldnt idle