We are thinking of buying our teenaged son (16yr. and 135#) a Suzuki 400. He right now has a YFZ450. He rides this thing all the time and we have to have it rebuilt every year. This is getting to costly for us so we want to get him something thats not RACE. Will he have enough power to dune and wheelie like his 450? Any insight will help.

it will but going down in CC's doubt he will be happy..

if he is tearing up a stock yfz he will probally do more to a less powerful bike,, (in my opinion)

what the hell is he doing to the yfz. they are strong bikes. like esco said he is going to be on a 400. Maybe a Honda 400. very reliable bikes

His butt is always on this bike, we go out about 10 times a season. First season was a top end (Piston, rings, valve adjustment). This season bottom end ( crank, timing chain, crank bearing, valve adjustment). Everytime it cost us about 5-6 Franklins. The service dept. at all the shops say they need to have them rebuilt every 20-40 hrs. because these bikes are built for HP.

Had my '05 YFZ450 since Dec. of '05 and haven't had to open it up yet!!!! Out about 6-10 times a year and run hard - no desert racing but I ride it hard! There is no way I could go down to a 400... it's not only the cc's you are dropping down... the whole way it is designed - HUGE difference. I don't think he would be happy going to a 400 and not even sure if he would last any longer through a 400.

Perhaps making him pay for his own maintenance he will slow down a bit and take care of that machine if he is responsible to fix it! I still don't understand what he is doing to those motors for a rebuild every year, unless he is desert racing for long amounts of time...

Keep us posted on what he thinks and what you plan to do...

I just can't under stand why his bike needs so much repairs on it also, I think this needs a new thread. thanks.

P.S. he does pay for his own repairs

Yea, no way he would be happy going from a 450 to the Zuki 400.

I'm a banshee guy and I dont even have to rebuild my bike that often...

A few friend I know have YFZ's run the hill constantly half the day, and then go play in the dunes, and they have a few seasons on theirs motors with no issues.

same here...have an 06 YFZ and haven't had any of those problems! These bikes are pretty bulletproof and believe me i ride it hard and it hasn't skipped a beat!

i have personally ridden a piped 400ex Honda and it was much slower than my dads stock Zook 400. the 400ex has a very broad power range and there really is no hit to it. The LTZ at least has a little hit to hit in the top end and can be built to go fast but it will not be anywhere near a YFZ. I don't know what he is doing but something sounds wierd because the yamaha is a great bike!

Sounds like you need to watch/listen to how he is riding. Sounds like he may be over rev'ing or something in order to be messing it up so bad each season.

no way... he will be very disapointed.
Do you want brand new or used?

Sounds like somebody needs to learn how to fix his own stuff. Might save you a couple of $. You might also learn that the service center is you on a regular basis.

it just hit me what the problem COULD BE... i ride with a group with ages from 7-56, and the problem with all the kids 7-16 is they will run one gear a whole ride cause they havent built up confidence to shift while duning, so they will PINN bikes in 3rd... but wont shift because they dont trust themselves... after 2blasters and 3 banshee's later (2nd day of a 10day trip.... and did the repairs in 1 dayt..........). we started listening to them ride and thats what theyw ould do, they would find one gear and stop in that gear, wouldnt go up or down. since correcting them on this we havent had ONE failure in 3 years. I think he might be over revving or bangin off the revv limiter

you need a new mechanic!!!!!!!!! no quad should need that kinnna repairs. even the racers dont rebuild em that often!!!

the Z aint even close to the yfz in power, he will be majorly disapointed for sure. if the kid is good enuf to handle a strong yfz, get him on an 08 ltr!!! he will be a happy camper for sure!!!!!

The 400ex or Z400 has enough power to get him around anywhere in glamis, no question about that. The issue is will he be happy going from a 43 horsepower bike to a 35 or even 29 hp? Probobly not. The YFZ should last an easy 3 years or longer with proper maintainance.

My 17 Yr old had a YFZ that he rode very hard. I think he spent entire dune trips at the race hill and the drags. The only thing we had to do, other than change the oil, was adjust the valves. I wonder if you have a lemon or maybe just a motorcyle shop that just wants to make alot of money off of you. I think your son will be disappointed if you go down to a 400. Just my opinion.

well from a 16 year-olds point of viev downsizeing is never good and the zuzuki 400 cant even compare to the YFZ450 but if u want a bike that will last forever get a honda 450

Dude it's simple. These new 4 stroke motors were developed using formula car technology. At least with a CRF450 it's considered a closed course race bike. Hence no spark arrester or air restrictions. Read in the manual. Every 15-20hrs you should check valves. Every 35hrs is a piston change. Sure you can run a bike for 2yrs hard and never have to open her up. But when you do take a micrometer to the piston and cylinder and compare the numbers to the spec. Unless he had ran it hard on tight valves the Mechanic is just hosing you. Unless he is a die hard racer their is zero point in rebuilding it every year!! Small motor HUGE HP less reliability.

HONDA!!!!!!!! TRX450R it the way to go!!!

You may really be havin problems........I'd check the air filter first. Make sure you don't have a hole somewhere letting sand in. How often do you change the oil??? What kind of oil are you using??? Valve adjustments on a yfz are a pain in the arse (bucket style) But once they're adjusted you should be set for awhile!!!
What kind of parts are they usin when they rebuild it??? Crappy parts won't last. I have 2 04 yfz's and niether one has been apart other than retarding exhaust cam. I change my spark plug twice a season (an over-looked maintenance item) change the oil every third trip (I have a car too, so I don't put a ton of hours on it) And this summer will be the fisrt time mine is bein taken apart (but just for some head work, port & polish) and I'm gonna do a piston and some cams, but just cause I'm in there. KEEP THE 450!!! Have someone else look at the bike and get only good parts in it and make damn sure no sand is gettin in!!! K&N is known for this as they age!!!

I believe the valve seats on the honda are steal and the valves are titanium, reason for adjusting valves consistantly. YFZ valve seats aren't steal, they are titanium also I believe. reason why YFZ's valve train is more costly then Honda (not because of one extra valve). audi uses the same design of a cylinder head in their engines. so does volvo with one less valve. Yamaha help design engines for both companies. as far as a full race for the yamaha's and the rebuilds, that just recommend. id say about 80% of all yamaha 450's being quads or bikes dont require what the owner of this topic is going thru. as for Blackmagic1450's post on running in third gear consistantly, I think that is the answer to this problem. His son does wheelies all the time, you stay in one gear to "show off" wheelies. there are two types of wheelies, power wheelies and show wheelies. power wheelies only bring the wheels off the ground maybe a foot, keeping the motor at pretty flat level, and not to mention if your a expert rider, shifting while the wheels in the air gaining more speed. show wheelies put the engine at an angle that is not made to perform at starving the oil pump. thus failure is prominent. quit doing wheelies, shift gears and I bet this ride lasts a long time. I've beatin the S*** out of my 450! I've tore the whole front end off racing. lake bed top speed passes. feather clutching/dump clutches at full throttle at the mx tracks, engine braked it to where Im locking up the tires. so you need to find another mechanic to work on it or your son cant ride the quad properly. it may possibly be both issues or one or the other. I think it would be a waste to get any 400cc ride. no comparison to any 450. also how many of you warm your quads up for 10 minutes before a ride, check the oil ?

Just my opinion here...get a used 400EX that has been taken care of. They don't have the power of a YFZ, but throw in a stage 1 HotCam, a pipe, a good air filter, some good shocks, and go dune. They are very reliable. I beat the piss out of my 01 400EX 4-5 times a year at the dunes and every weekend year round on the local trails and it just keeps going. Change the oil regularly, keep the air filter clean, and keep the valves adjusted and you will never have a problem. Mine has never been tore apart (except when I put in the cam) and it has hundreds of hours on it and still runs great.