05 engine vs 06 +

[quadfmx]

I have been reading up on building my trx450 engine, It is an 06 engine. I came across some stuff online and was told by a couple of engine builders, that most of the GNCC pros preferred the 05 motor over the 06-07. It mentioned the 05 revving slower and something about the stoke being different.
But i thought a lighter or heavier flywheel would get your revs up quicker or a weighted one would remedy the quick rev if you didnt like it,
I had just never heard this or read it anywhere I was asking hasd anyone else heard this information

[KEVIN300A]

The 05 is a faster motor all around bud... I owned an 05 and 07 and the 05 walked on it in trails and straights no matter if I was riding it or my buddy def. seems faster idk why tho....

[BadinBlack]

Originally posted by quadfmx
I read the other day, It was talking about in 06 and 07 alot of GNCC pros was still running the 05 engine b.c they liked the stroje of it better, It was saying they liked the slower rec.
Id sny of thid true
what?

Originally posted by quadfmx
I read the other day, It was talking about in 06 and 07 alot of GNCC pros was still running the 05 engine b.c they liked the stroje of it better, It was saying they liked the slower rec.
Id sny of thid true

WTF?

What does that mean. can you edit it and repost what your asking.

[airmobile101]

Originally posted by quadfmx
I have been reading up on building my trx450 engine, It is an 06 engine. I came across some stuff online and was told by a couple of engine builders, that most of the GNCC pros preferred the 05 motor over the 06-07. It mentioned the 05 revving slower and something about the stoke being different.
But i thought a lighter or heavier flywheel would get your revs up quicker or a weighted one would remedy the quick rev if you didnt like it,
I had just never heard this or read it anywhere I was asking hasd anyone else heard this information
The 04-05 has a longer stroke than the 06-07 models according to the service manual. 04-05 is 64.8mm stroke and a 06-07 is a 62.1mm stroke.
06-07 has a larger bore: 96mm vs. 94mm bore of a 04-05. Compression ratio is as follows:
04-05: 10.5:1
06-07: 12.0:1

[RosquistRacer39]

From what I have found out is that most guys went with the 04-05 motor because of the tranny being much more reliable than the 06 and up years. The motors can be made to haul as well but mainly for the stronger bottom end.

[fmfhonda250r]

I have 2 05's and 2 07's and i race mx and worcs. I like the way the 05 motors run better. More low end and smoother power they dont wear you out. The 07 motors have a hit to them and some riders like that. The 06 and newer machines make more power stock but once build they dont make quite as much but the 05 motor takes more to get it there and takes more money. The 05 style motor has ALOT better transmission as well wich is primarly why i like the older motor better jmo

[airmobile101]

Originally posted by fmfhonda250r
I have 2 05's and 2 07's and i race mx and worcs. I like the way the 05 motors run better. More low end and smoother power they dont wear you out. The 07 motors have a hit to them and some riders like that. The 06 and newer machines make more power stock but once build they dont make quite as much but the 05 motor takes more to get it there and takes more money. The 05 style motor has ALOT better transmission as well wich is primarly why i like the older motor better jmo
I think the FCR carb has alot to do with wearing yea out. This isn't the first time I heard that about the 06 and newer quads. Those FCR carbs just flat out hit hard!

My 05 felt so fast, until I made my car faster and now the power is boring lol Its stock so it could use an uncorking.

[lowbudget36]

You can get more power out of an 05' exactly why Byrd always ran them.

[warr72]

The 08 er has a different style cam in it and eats up the lower year R's with less mods easily.

[warr72]

Also you can you can make a bada** motor by putting a few of the different years together into one, if you know which ones. :p

[kenny450er]

care to share this info im all ears.

[coryatver]

the 06+ with the hrc kit makes crazy power over the 04/05. But when you get into thousands of dollars in head work the 04/05 motor comes out on top. And the tranny is better but some shops have a mod to fix the 06+ tranny

[kenny450er]

what problems are they having with tranny and what the mod to fix it

[warr72]

Not when you run the right crf goodies with that 08 er motor.

[kenny450er]

your killing me whats the secrate parts list for 06+

[coryatver]

Originally posted by kenny450er
what problems are they having with tranny and what the mod to fix it

the gear coggs don't match correctly. Some engine builders fix it by machining the gear coggs. I have an 06 and haven't had any problems yet but it sure doesn't shift as smooth and nice as my 400ex did.

[quadfmx]

check out moto-xperts page and it talks about the 450r transmission problem.

But here is my question i thought the 04/05 was the same. I know there was some bearing failure in some of the 05's early on i thought there was a recall but I was un sure.


Has anyone else found out any info on runninf the crf head on the trx to get more power?

I have heard of dirt bike guys who have the crf450x or the 250x runinng the r head for the more power as the X was detuned

[warr72]

The 06 and up bottom ends need to go on the grind to make em as bullet proof as the 04/05. You can make a stroker motor using nothing but TRX parts from the different years. It will look completely stock but once you run it people will know something is up, as they will not keep up, if you can ride. I have built a good number of them now and got a lil bling to show for it, lmfao. CRF ignition makes this motor even more sick. :devil:

[250rPRIDE]

ha you guys are freaking me out i just got a 06 thats mint for a great deal, under 10 hours for 2100.. but if i have to worry about tranny problems then i dont want anything to do with it. if i just do a mild cam crf or hrc and pipe filter ect. will it hold up fine for a good woods trail bike??

let me know. thanks

[veenser2000]

the transmission problem is not as big as it is being made out to be... usually the people tearing them up are racers with a long list of mods.. and when they race they don't operate the machine correctly causing failure...

[250rPRIDE]

ok that eases my mind a little bit haa, i dont race but i ride hard, little jumping lots of hill climbing and drag racing powershifting ect. will it be ok with minor mods then?? i was thinking cam pipe air filter jetting and mabe some porting

[bwilliams450er]

You're fine if your just trail riding. just using the clutch whenever possible (which in your case should be all the time, because your not racing) will make the bottom end last a lot longer. I had an 04 450R and now have an 06. The 04 def felt like a stronger tranny, the 06 seems to miss second occassionally when i'm racing. a little clutch when your bangin gears goes a long way on the bottom end

[bwilliams450er]

Originally posted by fmfhonda250r
I have 2 05's and 2 07's and i race mx and worcs. I like the way the 05 motors run better. More low end and smoother power they dont wear you out. The 07 motors have a hit to them and some riders like that. The 06 and newer machines make more power stock but once build they dont make quite as much but the 05 motor takes more to get it there and takes more money. The 05 style motor has ALOT better transmission as well wich is primarly why i like the older motor better jmo


My 06 def rides a lot diff than my 04. The 04 is more of a smooth continuous torque pull, where as the 06 hits hard and rides like a 2 stroke. the 04-05 motor def has more lugging ability. the 06 + is more of a high strung motor that likes high revving. and yes, the FCR carb def has a lot of responsibility for the differences