Are the YFZ 450s reliable

[2500258]

Hello, I right now have a 2004 440ex and i love the power, Performance and suspension however i hate this air cooled ****. I am looking into the yamaha YFZ 450s but i have a few questions. Are they reliable, are they built well ( hows the engine bolted together, screw head bolts or regulars) also whats the deal with the valves always having to be adjusted. i am mechanically inclined and am capable of adjusting them but how often does this need to be done? any help would be great thanks.

[Trxracr]

are you looking at the standard or the new r model i dont have any experience with the r but i love my 08 ull be amazed at the power with just simple mods as for reliability ive never had problems with mine and ive had it for almost a year of riding hard every day where i ride if im not turning its wide open so i no it can take abuse. with the valves the book says to check em after break in then every six months but after ten months mine are still in spec. about a month ago i rolled her at about 60mph and all that happend was bent plastic n bars and it rolled about 5 times so theyre tough! just outta curiosity have you ever had that 440 on a dyno?

[Toadz400]

Why are you sick of "this air-cooled sh*t"? What's wrong with it? If you're happy with the power and suspension of your 440EX then I would stick with it.

YFZ450's are going to be just as reliable as anything else if you take care of it. Do regular maintenance, etc., etc.

As for the valves, I've never had to put shims in mine and it's got at least 300+ hours on it. Still in spec the last time I checked it. Mine's an '05 and everything is original besides a-arms, axle, and handlebars. Still runs as strong as the day I brought it home.

[WoodsRacer16]

A 450 IS A RACE BIKE WITH A RACE MOTOR. THEY RUN HOTTER AND REV FASTER. THIS MEANS MORE PROBLEMS. IF YOUR NOT GOING TO RACE IT DONT GET IT. WHY GET A RACE BIKE IF YOUR NOT GOING TO BE ON THE TRACK EVERY WEEK. I RACE A YFZ450. I HAVE ALOT OF FRIENDS GETTING YFZS CUZ THEY WANT TO BE LIKE ME BUT THEY DONT RACE.THEY DONT TAKE CARE OF THERE YFZ'S AND THEY HAVE ALOT OF PROBLIMS OUT OF THEM. I EVEN HAVE ALOT PROBLIEMS WITH MINE AND I EVEN TAKE CARE OF MINE. ITS ALOT OF MONEY TO KEEP THE 450S RUNNING MAN. BUT I MUST SAY THE YFZ IS THE MOST reliable 450 out there.

[B-rad D]

the yfz isnt just for racing, they dont have lost of problems, just the people that dont know how to keep them running good have problems

[shawn3389]

i sold my 400ex and got a 05 yfz450 and love it

[BakerRacing40]

i haven't had issues out of mine, well maybe a temper tantrum or two, right before the races...

and with any quad, a clean quad is a happy quad!

o and another muddy sandy water muck stuff is the absolute worst thing you could to any quad, and for those that are like " i go through that kind of stuff and i don't have problems?" i hope they never have to tear it down, cause it can turn into a pain in the rear real quick like.. lol

[yamahahaha]

they absolutly are, just dont hold them wide out for more that a mile or so, it will more than likely pop. keep up with oil changes, or ull b replacing a clutch...take it from someone whos done it

[Toadz400]

Originally posted by yamahahaha
they absolutly are, just dont hold them wide out for more that a mile or so, it will more than likely pop. keep up with oil changes, or ull b replacing a clutch...take it from someone whos done it

I can hold mine WOT all day long and nothing will ever happen.

WoodsRacer16, please don't yell.:D

[mbx5]

I have owned both.... I had a 426EX with works shocks and Roll Design arms, etc.. I was not happy with the power, but it handled great... I ended up going with an 07 YFZ 450... The stock YFZ's require some more work as far as handling IMO - they are less forgiving, and are harder to maneuver on tight trails.... But it isnt even fair to compare power... The YFZ stock motor revs higher, produces a 2-stroke-like power band, and rips better than a highly modified 400ex hands down.

My current YFZ has ARS-FX long travel suspension, Ohlins shocks, -1/2" rear swing arm, and the Z-bros link...set up for XC racing... It handles unbelievably well especially in tight trails with the shorter swingarm...

If you are after more power, and plan on racing - go with the YFZ... If you are happy with your current setup, stick with it - I am not sure a stock YFZ will make you happy w/o modifying the suspension to get the handling you are used to....I wouldnt make the switch based on air cooled vs water cooled alone....400ex's are great reliable trail bikes....

Maintenance wise I havent had many issues with my YFZ other than a bad neutral switch and some broken parts from racing...its been pretty solid...but I take very good care of it and do regular maintenance...

IMO Yamaha's valve train is a great design...they have a 5 valve setup opposed to most other 4 valve...the valves are smaller and do not get beat as bad as the larger 4-valve setups...not to mention they are hardened titanium...thats pretty trick for stock!!

[Ride1Rob]

Honestly, in stock trim if you race your gonna have issues. I bent A Arms, bent two axles, and cracked my swinger all doing MX. Had to spend money on aftermarket parts to fix that problem. Then the bikes with the extra motor mods would run away from me so I had to spend more money lol...

2500258, you don't have to race to purchase a 450. If you want the bike get it whether you race or not! If it's just field riding you do buy it, if it's trail riding but it, if it's jumping or stunting buy it! All these 450's are good for all stated above and 100 things more. Not just racing ;)

On the other side, if you have a bike like you have that you have invested alot of money into I don't know if I'd do it. Depending on what all you have done to that 400ex you may not gain much performance wise by making the switch.

[400grl]

For one thing, the YFZ450 is not only a great race quad, it's also a great trail/dune machine as well. I went from a Honda 440 to an 04 YFZ450 and never looked back. The air-cooled machines lose power after they get hot, and this used to frustrate the hell out of me!

Yamaha makes some of the best machines in the business, and you won't regret getting a YFZ, believe me! I have had two now, and currently own a YFZ450R.

Yes, they are reliable - they were designed/built to be that way for the average consumer. Start modding it improperly and messing with it, or driving it like you don't give a cr@p about it, or don't ever take care of it properly, and any machine is going to give you problems....

I raced the snot out of my 2004 YFZ450 for over two years - that is riding/racing twice a week for that long....half of that was when it was totally stock. It never gave me any issues.....I also duned it for dune season, and people thought I was crazy to be out there with my race quad in the sand....but again, no problems whatsoever.

The only reason I ever got rid of my YFZ450 was to get the YFZ450R - which I love even more (didn't think that was even possible!)

So...yeah....go for it! Make a smart decision if you are buying used, of course....and go have some fun!