Buying an 04...Opinions?

[yernkie]

I keep hearing people say to stay away from the 04 and 05 YFZ's and to get an 06 or 07. Why is this? I know the motor is different and the seats suck, but what all would need to be done to an 04 to make it reliable (oiling issues, any other issues)?

[cjkranz]

Short of a couple minor changes the '04 and '05 are nearly identical. In '06 Yamaha did approx 80 changes on the YFZs. Just a few include more CCs, reported heads, better oiling of the motor, new honda style swingarm, etc.. the '06s are noticably faster then the '04 and '05s.

[400exfan19]

your good with any of the bikes, the oiling thing isnt a big issue, they wouldnt sell a bike that has a big problem and not do anything about it. Dont worry just buy any year, im in the process of buying an 04 also. Just buy an aftermarket decompression plug, its only like 10 bucks on ebay and itll save you the worry of it poppin off

[Bill Fuller]

My '04 is still running strong. I wouldn't be afraid to buy another one. Absolutley the best ATV I have ridden. Zero DNF's due to mechanical issues.

[07yfz88trx]

they are all great bikes but if you can get one that has the oil mod or oil upgrade done to it so you won't have to worry about it

[400exfan19]

i havnt heard of any1 that has had the engine destroyed because they didnt get the mod done...

[quad janern]

is it hard to put a 06/07 449cc cylinder and piston in an 04/05 ?

many things you need to change when putting in that cylinder ?

[coryatver]

you don't need a bigger piston or cylinder it is stroked bigger not bored.

[yfzrider310]

would you think that a 06 yfz (stock motor) parts listed below gettin beat by a piped 05??? jw its really close but i still lose anything i can do to go faster. its got the spark arrestor out but thats it.

[Dune Surfer]

The 04-05 suspension is Very stiff, plus the seat is rock hard. They made 80 changes between 05 and 06. Trust me, get the 06

[07yfz88trx]

do the cam mod and if you want the exhaust mod and then rejet if you do the exhaust mod

[woodsracer144]

my buddy raced a 04 and he said its the fastest quad that hes rode and raced...im lookin at a 04 but its mx ready... but the 04 to mea re just as good because i think thatyour gonna mod the motor sooner or later so your gonna put the money in the motor if its a 06 + or if its the 04-05 and to me if you jsut gonna mod it alot just get the cheaper one.. .and take your time around you can find a 04 with aftermarkets for the same as the newer ones thats stock...

[nightrider05]

If you do buy a 04, check with the owner and see if they have done any motor work to it, if not most likely you will be doing some further down the road. I got lucky and just had to replace the crank, rod, piston and cylinder..my buddy on the other hand could only salvage his tranny gears and head..I have talked to at least 5 locals that all had the exact same motor problems on their 04's.

[Toadz400]

I love my '05, hasn't given me any problems at all!

Big difference between the '04/'05's and the '06 and up is the power delivery. They changed the design of the intake port (made it smaller actually) and stroked it to 449cc. The power is so much smoother. At a track I was on my '05 piped, intake, and cam mod YFZ and rode a few laps around the track. Jumped on a stock '06 and I was able to ride twice as fast and felt like I could ride all day without being tired.

The oil upgrade (different from the oil mod) should be done on the '04-'06 models. It's highly recommended because it squirts oil on the rod where there is usually a lack of oil. It doesn't automatically mean the engine is doomed to failure but it doesn't help it that's for sure.

[yfzrider45]

i have an 04 and the power is unbelivable due to premium fuel, kfx450 oil, engine ice as coolant and a hi-flow impeller to go with that...added with a racing spark plug, k&n air filter with airbox lid off, k&n oil filter. and i have a cams done!! Thats what i have and i notice a diffrence in shifting, i can stay in each gear longer...