Are the 426 or 450f reliable, high maintenance or both

I've been looking at used 426f and 450f and was wondering how reliable these bikes are and wheather or not they require a lot of maintenance. I prefer low maintenance and reliability.

Thanks in Advance,


I can only speak for the 426 as it's what I ride.

They are very reliable bikes. The only problem I had was my 5th gear failure, but as that happened the 1st day I had it, I put that down to inheriting someone elses problems. There are people who have had top ends let go, but when you have a piston almost 4" and you spin it to over 10,000RPM, these things will happen. I guess you could class then high maintainance. In this respect they are no different to any other high performance 4 stroke in that regualar oil changes and keeping the filters clean is a must. If you can handle changing the oil and cleaning the air filter every 5-10 hours, and cleaning the engine oil filter every 2nd change, and checking the valves every 2nd oil filter clean these bike will serve you well. People will have different opinions of maintainance schedules, but thats what I try and stick to. I'm sure if you get a WR426 or a WR450 you wont be disappointed. When you snap the throttle open and feel that classic 426 'hit' all the prep work is worth it 10 times over. A YZ timed 426 isnt just a bike, it's an addiction! :cry:

Hamish is right.

I change my 426 oil every 1000 km (500 miles). That usually comes with new filter or filtrer clean up.

I open the bike for valve inspection every 10 oil changes.

Never had a single problem with the bike so far...

Even people used to ride XRs around me think it is a pretty reliable bike... U know what it means? XR people know what a bullet proof bike is so when they talk a bout reliability, they know their business.:cry:

Seriously, oil changes are easy to do, even if other bikes like XRs would survive not changing the oil regularly, you would be supposed to change it regularly anyway... I think WR's maintenance is just good manners you should get used to and apply to other bikes you have... nothing major really.

I'm not a mechanic guru at all... if I can do it... everyone on this forum can! :cry: Well there might be some rare exceptions but I'm not going into that further:D

Have had my 02 426 since new, change the oil & filter regularly, had valves inspected (had never need adjusting) Never left me stranded. Add in the fact that the 426 is green stickered :cry:

I just happen to be selling my 426, because I have a new 250f, and I live in Ca.

Let me know if you are interested.

I've had both, the 426 and currently the 450. All I ever did to the 426 was to service it regularly. Change oil often, adjust the chain, keep the chain clean and lightly oiled. I never had one single problem with the 426 and had thast for 3 full rding seasons. Well, OK, I replaced some fork seals, all went back to kleaking until I installed OE Yamaha seals. Cant speak so much for the 450 as mine only has about 110 miles on it, but it appears from others in here, should perform as well as the 426 did.:cry:

My 02 WR426 has been bulletproof.

i know of a 1999 400 with over 45000km on it. oil, valves, tires, chains, adjustments, and thats it. i would say they are very reliable for how much power they have.:cry: :cry:

i would say they are very reliable for how much power they have.:cry: :cry:

I think it summarizes what I think very well.

They wear out back tires much too fast! On second thought, you will save on fronts because they never touch the ground.

My 01 has been as close to bulletproof as anything I have owned. As reliable, if not more so as the XR600 it replaced. Probably less maintenance too. The XR ran hot so oil changes were just as frequent and it required 2 or 3 valve adjustments per season as opposed to one valve inspection.

IMO all motorbikes and atv's are high matainace...... IMO if you feel that you have a low matainance dirtbike than it is severley neglected.... frequent oil changes are a must, as well as air filter servicing and checking valve specs..

I severley neglect my bike and it runs like a champ!

I change the oil, put gas in it and BAAAP! BAAAP!

I have an 03 450. I had a problem with the woodruff key up front but since, no issues what so ever. :cry: I wouldn't call either bike high maintenance. :cry:

All off road equipment requires maintenance but the the WR doesn't require anything special or above the average.

The 450 will give you an electric start where the 426 doesn't have that feature and has had a reputation of being tempermental when it comes to starting.

Bottom line, you can't go wrong with either bike. Get the one you want and twist it! :cry:


45000km on it :cry:

This is a big distance. I hope mine with all the tender and loving care I provide will last that long !


I'd avoid the 03' WR450 like the plague. Any other WR426 or WR450 should be very reliable.

I had the 01' WR426 and once you get the jetting straightened out, it starts easily.

I'd avoid the 03' WR450 like the plague. Any other WR426 or WR450 should be very reliable.

I had the 01' WR426 and once you get the jetting straightened out, it starts easily.

I like riding my plague!:cry:

I have an 04 WR450 with a little over 500 miles, (I got it in September).

Change the oil every 500 miles after break in. Keep the filters clean. Check the chain tension a lot. Check for bolts losening up. Use Good gas and ride.

Oh yeah the valves, Keep an eye on them, adjust if needed.


Rocketruss, If you happen to purchase a 426 or 450 you won't be disappointed. they are both very good bikes, both reliable, you'll have lots of fun. The question is, are you reliable to look after your bikes and do the required maintenance when called for. If you take care of your bike it will take care of you. Good luck and have some fun on that bike if you decide to purchase one. I purchased an 00 426 and have loved the dog gone thing, it's got very good power. It's a nice bike. If wanting to purchase one go for it, you'll like it.

Change the oil every 500 miles after break in.:cry:

i would/do change it allot more often then that. like every 100-200km.......but that is just me:p .
I like riding my plague!:cry:

I know Dan :cry: but the 03's did have issues and didn't you upgrade the starter?

I have a 2000 WR which is as reliable as a falling brick. Still the original piston and rings.

The only thing that makes it harder to maintain than an XR is the fact that you have to remove the cams to change shims if and when you need to adjust the valves.

If you can handle a shim change than you are in 426 heaven.

The Yamaha's are supposed to be better than the Honda and Kaw/suki in terms of longivity.

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