I am looking at an '06 CRF450r and am new to the 4-stroke world. Is already having to rebuild the bottom end of an '06 out of the ordinary? He said a bearing was knocking so he rebuilt it. Sound normal or sound like it has been ridden too hard? Also, can these bikes be ran on pump gas? We have 93-octane around here. Thanks in advance for any help.

93 octane is fine and is what most people run. As far as the bottem end being re-built, you have to remember that it is a 2006. Usually the 450's dont get rung out nearly as bad as the 250f's, and will last longer. Just make sure you look for all the tell tale signs of maintence and or negelct and you should be fine..good luck

Just depends on how much its been ridden and what type of riding. If the bike gets ridden every weekend you can plan on replacing the top and bottom end every 18-24 months or so. If its raced hard, you will (or at least should) be replacing it every season.

Thanks for the input guys. The particular bike i was looking at sold before i could get it. But, i did find another '06 that i picked up. Took it out to the local MX track yesterday and noticed a few things that made riding a little tough.

The front tire was slipping outward on corners, even slight turns, as it would if the ground was covered in ice or something. I had 10psi in the front tire and will bump to 14psi and try again tomorrow. Does that sound like an air presure adjustment fix of something to do with the forks? The tire is new and has plenty of meat. I'm sure the forks aren't set up for my weight (220lbs.).

The next thing was the stiffness of the clutch. I am a novice rider but do clutch with my index finger. Very difficult to do so on this bike. I have searched around here on ThumperTalk and other pages to see what the easiest-pull clutch setup would be. Not to start another "that lever sucks, Joe-Blow is an idiot" topic, but what are you CRF450 guys that clutch with your index using? I run the MSR Pro-Raptor on my YZ250, and it works well as far as clutch pull easyness, but definitely won't handle a hit to the ground. Is the Magura Hydraulic clutch worth the $$?

Thanks for any input. And by the way, glad to be a part of the CRF crew! Love the power and rear suspension of the bike!

I'm the same weight plus gear and have .50 front 5.9 back springs that makes all the differance.. if the springs don't ride at the right level the valving dosent work right...
sometimes the clutch cable mount gets bent a little and will cause drag too get down where you can see the cable come out of the housing and bend the mount so the cable comes out of the center and not rubbing the housing and lube the cable

Checked the clutch cable and mount and everything looks good. Think I'm going to order the Magura Hydraulic today. Do I need to buy the bleeder kit? I would think that it would come as a sealed assembly and already be full of fluid, free of air bubbles, but of course tech support at every place I've called don't know the answer. I read on here somewhere that mineral oil from the local pharmacy is the same thing as the "Magura Blood" fluid, that true?

As far as the suspension....I have no idea what ".50 front 5.9 back springs" means. Can someone point me in the right direction on how to setup my suspension to my weight?

Thanks in advace!

thats the spring size and should be the first thing to do its like day and night

http://shop.thumpert...t.asp?p=605&s=2


http://shop.thumpert...t.asp?p=602&s=2

for the bottom end you will need one of these:

http://www.motionpro.../partno/08-0385

cheap tool. Also if you have the stock rear wheel, you will need this tool:

http://www.motionpro...partno/08-0256/

For the forks, you need a cap wrench:

http://www.motionpro...partno/08-0236/


For the clutch, buy a new cable. The stock pull is light on the 450s. stock lever or something like the ASV properch unit is great. Also get a cable lube tool:

http://www.motionpro...partno/08-0182/



and yes you need new springs in your suspension for your weight. If you dont know what you are doing, find a local suspension tuner or send your stuff out to one of the name brand places. that will help with the handling and everything on the bike. Check the valves, make sure they are in spec. Other than that, a new piston and inspecting the crank would be a good idea on a used 4 stroke. only wear item really on the bike beyond rear tires, is the clutch basket. Get a billet unit installed and you dont have to worry about it. last item is the throttle cables. replace every 2 years.

Thanks for all the info JJ! This is what the local RaceTech dealer/shop quoted me:

Front:
Springs $110
Valves $160
Oil $40
R/R forks labor $90
Revalve Labor $180

Rear:
Spring $110
Valve $160
R/R Shock $90
Oil $10
Revalve $120
Seal $10

Total around $1,000. Does that seem reasonable? And I believe i will take your advice and get a new clutch cable and a cable lube tool, along with a shorty lever.

Thanks for any replies.

save yourself some cash and do it yourself buy a manual like this http://www.ebay.com/...=item5ae48a4e91

I buy most parts on ebay and here on TT

call factory connection RG3 and check for local suspension shops to you.

Being a novice rider, therefore not needing all-out performance, would there be a be big difference from the horrible handling of the bike now if i just had the springs replaced to my weight and riding terrain and not the whole spring and revalve job? I could save alot of money going that route. Thanks for any replies.

yes nothing wrong with stock valving just get springs and put them in yourself

Thanks for the replies. Looks like i will go with springs and install them myself.

Thanks!

fork rebuild should be good, make sure your sag is set right.... and theres nothing like a fresh bridgestone 403 on the front