reliability, 400ex or 450r

[darkzealot]

What do you think is more reliable ?
400ex with aftermarket exaust, k&n filter, aftermarket cam,bored 416 11:1 compression piston ( lets say JE ) port and polish job and crf450r timing chain OR stock 450R

considering that the 400ex was build correctly...

i have a 400ex right now, and im wondering if i should mod it or simply buy a 450r (used). reliability is an important factor for me. I wouldn't want to have to rebuild the 450r every year...thats why..

thank you

[AtvMxRider]

It's hard to beat a 400ex for reliability but when ever you modify anything you lose some. But I would still say the 400ex would be more reliable.

[CHEVYZ]

I would probably say 400EX, but it would be close.

[the predator]

you can't beat a 400ex for relibility..no matter what mods are done to it.

[d3ktrix]

If you do all those mods to a 400 you can throw all that reliability right out the window. Cuz it will be the same as any other perfomance engine after that.

Stock 450r's are really reliable IMO. 2 of my friends have all stock 450s and they beat the hell out of them and there still going with a few years on them now. With the only maintence being far between oil changes.

The 450 is just an all around better bike too IMO, mainly being the shocks and engine.

I bought a brand new 05 400EX, owned it for 3 months and traded it in for an 05 450r. And I will never look back =)

[sandmanblue]

You know, the reliability of that 400 is going to depend on who put it together too. I can't imagine that there's be a big change in reliability of it unless you do a few specific things like: stroker crank, big cam, big valves, big bore piston. If all you did was change the cam - then it depends on which cam you use. Something mild like the HotCam Stage 1 won't do much damage.

What messes things up is big parts moving at high speed...

If you equate hp and displacement with these two motors - make the 400 a 450, and let it rev to 10,500 and make 47 hp, then mod the 450 with a cam and pipe to get it to do the same, you have a comparison to look at.

Somehow, I think the 400 modded like that would be a grenade...

[450raider]

rebuliding the 450 every year :confused: i dont think that would be neccessary if the dude you buy it from really did take care of it, otherwise for reliability id go with a cared for ex.

[mic 902]

Considering that most bike manufacturers have got the bottom end of engines worked out most of the reliability of a 4 stroke bike/quad comes from the head. The head in the 400ex is simple and effective, from what i understand the head in the 450r is similar to that in the crf450 and on the bike forums guys with all these new 450's are dropping valves left right and center. The 400ex engine is almost a carbon copy of the xr400 with only a few changes to make it more suitable for a quad, i have never heard of an xr400 with problems, they just keep on running.

Hope that helps.

[Flodies400ex]

I had my 2004 400ex about 1 year now then I got my 2006 450ER about 2 months ago and I had np and I still my 4 year warrenty but overall the 400ex are good bikes and they can take an beatin and still live threw it and I always #1 thing to do with my bikes is always after I get done riding I always wash it to make it look brand new still

it just depends how well you take care of it

[darkzealot]

thx guys ! i appreciate your answer

[DEAL]

only thing you have to look out for on a modded 400ex is headstuds and head gaskets .. Which is a minor repair compared to some of the 450r problems we've been hearing about.

[400exrider707]

Thats low enough compression to be reliable still, I would still say that the modded 400ex you are talking about would be more reliable than any 450R. The 450 is a purpose built race engine, while the 400ex is a trail quad. The 450R would definitely need to be rebuilt at very minimum once a year if you race, the 400 will run forever....

[darkzealot]

you know, i want to mod my 400ex or get a 450r cause i want to be able to clear bigger jump and go faster. But i dont do any race, planing to do so in 2 years maybe, but for now im just playing in mx tracks with no competition. I like having fun with my friend doing big jumps in his track. Right now, my lighty modified 400ex wont give me enough power to clear the bigger jumps.

I know ill get more power and speed from a stock 450r then a 400ex modified like mentioned at the beginning of my thread.

Someone mentioned in another thread that the 450r become KaBoum when you put high compression piston on it. But if i dont plan on doing any mod on my 450r ( or maybe just pipe it ) would it be the good quad to have fun in trail and for jumps ? Is the reliability good enough for that kind of purpose.... for some1 like me that doesn't expect to trow ton of cash to repair it or upgrade it ???

Thx you !

[krt400ex]

Originally posted by darkzealot


Someone mentioned in another thread that the 450r become KaBoum when you put high compression piston on it. But if i dont plan on doing any mod on my 450r ( or maybe just pipe it ) would it be the good quad to have fun in trail and for jumps ? Is the reliability good enough for that kind of purpose.... for some1 like me that doesn't expect to trow ton of cash to repair it or upgrade it ???

Thx you !


that is way off. a friend of mine races a 450r with a 14:1 comp piston. his has never gone KABOOM. he rebuilds it yrly though, but he has never had any probs with it.

[JW450R1]

if your asking for both machines being stock trims.my opinion is there both reliable.besides it's a honda toooo:D

[proff x]

any honda is reliable i beat the snot of my 450 and my 400 and have had no problems ive built a 416+ and its trhe same exact thing i would go with 450 only cause the motor i built was 3mm bore and a 440 4mm and its air cool ed so there are possible over heating problems
over all go with the 450r

[darkzealot]

any1 could tell me what are the common problem with the 450r ? What are the known problem with them.

[krt400ex]

i haven't heard of any "well known" problems with them. i have heard of a few things here and there, but that is mostly cuz ppl abuse them and then they don't want to maintain them properly.

[oldskoolex400]

if your 400 is stock sell it and go with the 450