any known problems with 04/05 trx450r's?

[mineralgrey01gt]

Im looking at getting rid of my 2008 kfx450r and a guy got in touch with me wanting it, he has a 2005 trx450r with stage 3 hot cam and getting a brand new top end as I type this put in by a shop. He also said he put better clutches in it than oem. He offered me his bike and $200 cash. Im curious as to if this is a decent trade or not. The bike doesnt look to be in bad shape but we all know how pictures are. Is there anything I should look for particularly on the 04/05 models?

[CJM]

Other than the cranks going bad on them, not much goes wrong.

12:1 piston and stage 2 hotcam as well as ported head make a good 50hp on these things.

[punk rock kiel]

kfx is worth way more than his bike from the sounds of it. I don't know the downfalls but a kfx is a good trail machine and id say has way more positives than a trx

[mineralgrey01gt]

Looks like ill be getting rid of it for a different trx450r, a guy hit me up to do a trade on one with a hot cam, 1st bore fresh top end, not bad at all, ill clean it up and redo it to my style. Probably going to do a throw back to the 250r look from 86

[fastredrider44]

Be leary about the "1st Bore" comment. These are Nikasil cylinders and boring them is a no no unless they went with a big bore piston and either bought another cylinder or sent their cylinder off to be resleeved or bored and re-nikasiled.

[mineralgrey01gt]

I got it tonight, it runs really good, slight lean as the header starts to glow after running a while but nothing major by any means. Im probably going to start tearing it down to redo it and fix any little problem it has. Where is a good place to buy aftermarket parts for these?

[CJM]

Whatcha want parts wise? Tons and tons of stuff available

Headers always tend to glow, thin metal and these suckers get pretty warm. Jetting it right helps some.

[mineralgrey01gt]

Whatcha want parts wise? Tons and tons of stuff available

Headers always tend to glow, thin metal and these suckers get pretty warm. Jetting it right helps some.


Ahh so it might be good just glows some huh? Its a full curtis sparks exhaust on it, claims a hot cam in it also but not 100% sure on it, just going off of what he was told when he first got it. Im looking for some front fenders for sure, is there any brand besides maier? I need a bumper, grab bar, some nerf bars but I think im about to pull the trigger on some pro armors on ebay. It is leaking gas out the carb so im going to tear it down tomorrow and readjust the cable since if you turn it fully to the right it revs up. It doesnt idle right now but im sure i can get it to do that. Its a solid project bike.

[CJM]

Besides maier really nothing for fenders besides oem.

They all glow, but it could be lean. The head pipe on a sparks could also be thinner than others IDK for sure.

Proarmor nerfs are the way to go, I love mine.

What really needs attention on these 450s is the valves, if they arent in spec or are worn out the quad doesnt like to start all to well.

[mineralgrey01gt]

Glad you said that CJM, I heard the bike run and I rode it last night when I got it. Now he did mention that had to pull start it to get it to crank the first time. Its backfiring out the exhaust so first thing I thought was timing, I checked it and all is good with the timing. Now im thinking its a valve adjustment needed. I already looked up how to do it and doesnt seem to bad, just have to wait on shims to come in to do it and go grab some feeler gauges. Is that a good idea of what it could be? Also I kicked it over, again i rode it last night and there just doesnt seem to be any compression, now it could just be that I am not used to kicking a 4 stroke as they have a compression release.



Also ill add it will not crank, it will back fire out the exhaust often but will not crank, has spark and is getting fuel. Also did confirm is has a stage 3 hot cam in it

[mineralgrey01gt]

Well solved my own problem I guess, the intake valves are way too tight which would indicate to me the backfiring through the exhaust

[CJM]

Well solved my own problem I guess, the intake valves are way too tight which would indicate to me the backfiring through the exhaust

Welp, shimming them might help. But its possible its time to replace the valves.

[mineralgrey01gt]

When doing a valve job it's pretty much just the valves and springs that need to be changed right?

[CJM]

When doing a valve job it's pretty much just the valves and springs that need to be changed right?

Depends, if the valve seats are done for its time to have them cut. If your gonna put together a awesome setup it would just be worth it to send the head off to a shop like racers edge or oregon coast powersports, or such and have them make the determination. The valve guides might have wear, etc.

When I had mine done I did +1 valves all around due to the seats needing to be cut and I also had it ported at the same time.

[mineralgrey01gt]

I ordered the shim kit so I'm going to try it out first, it does run but obviously after its hot. I'll shim it this week and see how it goes

[fastredrider44]

After the valves get super wore out, they can actually get pulled up into the head, so I would pull one of your intakes out and see how wore it is before you start going crazy with the shims. If the valves are murdered, your head probably is too, meaning you need seats cut, (not a big deal) or possibly have some seats installed. (also not a big deal but a little more $) Most of the time I don't fool with changing out my springs either.

The leaking gas out of the carb is probably the float needle. Ethanol gas hardens them and they won't shut the gas off like they're supposed to.

Lastly, I'm not sure what kind of riding you plan to do but a Stage 3 cam is all top end.

[450rtt]

Besides maier really nothing for fenders besides oem.

They all glow, but it could be lean. The head pipe on a sparks could also be thinner than others IDK for sure.

Proarmor nerfs are the way to go, I love mine.

What really needs attention on these 450s is the valves, if they arent in spec or are worn out the quad doesnt like to start all to well.

so glad that you have made the turnaround. I have seen countless threads in the past 5 years or so where you have argued to the death about the red glowing header. You've learned well young buck, they do sometimes glow even when jetted perfect. I'm impressed that you've come to terms with this, it really does help to pay attention and learn doesn't it?

Rath or Houser is where it's at for nerfs if you want something quality use those, they're big money but they're hands down the best. I've got 2 450's. One of them is a 05 with original crank. I probably have 200 hours on it and have only shimmed the valves 1 time. The valves do not need anymore attention than any other quad, just keep good oil and a good air filter and you'll be fine. What does need attention on these is the motor oil needs changed before 10hrs or so, unlike some of the other quads, these do burn up oil quick, as in, it breaks down faster seeing as the motor runs on less than a qt.

[DnB_racing]

I've got 2 450's. One of them is a 05 with original crank. I probably have 200 hours on it and have only shimmed the valves 1 time. yup run them real easy and they last a long time..its only when riding hard like they are meant to that things wear down

[Ruf Racing]

^^ You are correct and too funny, Barry!!!!!!:D

[jimmi]

yup run them real easy and they last a long time..its only when riding hard like they are meant to that things wear down

valve wear has less to do with how the motor is run and much more to do with maintance. keep clean air and fuel going in and you'll extend the life of valves.

[DnB_racing]

valve wear has less to do with how the motor is run and much more to do with maintance. keep clean air and fuel going in and you'll extend the life of valves. of course keeping up with things helps, just as much as having a mild stock cam, and if you have a stock cam im sorry to tell you this but its not running very strong .......shimming even just once means valves are worn, and starting to cup, and once worn to the point of needing new shims, the only way they last is not running hard, the cleanest fuel mixture wont matter any coating is already gone...cam selection has as much to do with longevity as being clean, so in this way yes how the motor is run does matter, as I said they last a long time when not running it hard!!!

I change oil every tank, clean filter every ride, and c12 only ..and there is no chance in hell it will make 200 hours on my valves, my top end gets rebuilt every 50 hours max