04' YFZ 450 Q's

[krizo88]

I took the air box lid off and the spark arrestor out on my YFZ 450. By taking the spark arrestor out it gave it alot better sound. I was wondering if taking the arrestor out will damage the motor any. And is there a chance I have to rejet? I havent rode it yet because I heard that it could damage my motor. Any of you guys have one of these machines? If so what are some quick mods that can be done to them? Am I gaining any power by taking the air box lid off and removing the spark arrestor? Thanks Chris

[trikerider2oo7]

taking out the spark arrestor shouldnt hurt anything...except if you are ridin thru a nice dry field and a spark comes out, the whole thing is on fire before you know it

[yater]

I ran my 200x without the spark arrestor and never had a problem. Might want another opinion on such an expensive machine though.

[KASEY]

a bigger concern would be running lean and burning your motor up,,, taking the lid off and the spark aresstor out changes airflow,, which in turn means a jetting change,,, i would put it back on and leave it ,,, more noise does not more power on a stock machine,,,,, call and talk to your yamaha dealer,,, i am sure they will try to sell you hop up parts,, but at least you will be informed about nessesary jet changes that need to be made........................

[krizo88]

I called and the guy that I talked to said I dont need to change jetting, but then he said even if I put a aftermarket pipe on it, I woouldnt have to re jet, which I think he is wrong. What do you think if I put the lid back on it and left the aresstor out (bent it up pretty bad taking it out). Its hard to tell if its running lean because the thing never smokes. Maybe I should just put it all back together and buy a pipe after the motor is good and broke in.

[cliff2302]

read your plug, it will never let you down. should be light gray to tan color. if it is too lean it will look white. heres a link to look at.
http://www.triumphspitfire.nl/plugs.html

[KASEY]

so i have to ask,,, what would the reason be ,, to start stripping stuff off a BRAND NEW $7000 machine before its even broke in???

[packhamstruck]

I would change it back to stock at least for break in,

question for you guys though if you put a YZ450F cam in the quad will it add much if anything, there is a used one for sale and it said it has it done and its the fasted quad you can buy? is this true

[KASEY]

i have ridden with several 450's and the fastest one i have seen ,, had a full exahust system , airbox mod, and the cam mod that yamaha does,,, same cam different timing,,
it was plenty fast too,,,

[krizo88]

Well the main reason I took the spark aresstor out is to kind of give me an idea of what it would sound like with aftermarket exhaust, and the reason for the lid was just to see if it would give it a bit more power (which it didnt) so I put it back on. I am trying to get the 450 to keep up with my R. Anyways I just couldnt see myself spending 7 grand on something and not tinker around with it. Thats how you learn. Taking it out to our local track today to burn around. You guys think 10 dollars a day is a bit steep to ride a track? And 15 a day for dirtbikes? The place used to have a membership for 27 bucks a season, but this year they arent offering a membership. I am going to have to buy up some land and make my own track. :D

[BLAZERONE22]

If you want to tinker with it, pop the lid, drop the needle down 1 clip, jet up a couple sizes, and yank the arrester, My dumbarse buddy just did it to his 7000.00 quad and he said it made a difference. He's insisting on a hard breakin. Bluetraxx.com is a good site for the YFZ, I like the quad, not bad for a golfcart.