Hey guys, I'm totally new to the CRF side of Honda and found myself with an '05 450X. For the last several years, I have been messing w Honda trikes (250Rs and 350x) and it's been an experience working on these older (ancient) machines. I have found that there isn't much you can't do with tools, a shop manual and the right attitude.
So...here I am w a (fairly) modern liquid thumper. I found it listed in a small town a few hours from me and the price was right. The seller needed cash and was honest about the fact that he couldn't keep it running. He has had it for several years and never really had time to ride it.
When we met for me to look at it, he had to jump it to get it to fire...no big deal...dead battery I thought. I rode it for about 3 minutes before it died and I couldn't kick it back to life. We tried to jump it for a while and never could keep it running. That's when he started tuning it.
He simply twisted the carb in the boots to access the fuel screw and that's when I noticed that it didn't even have an insulator band on the venturi side of the carb! Obviously the filter side was too loose as well. (I do realize that I may be looking at a top-end and possibly a new bore...maybe even a valve job because of this extremely lean condition.)
I asked him to quit jacking w it and I offered him half of his asking price...eventually he took it. I guess he didn't feel like loading it back up and driving it 2.5hrs back home...or just glad to get rid of it.
After I got it home, I started tearing it apart.( Yes, I do have both the Honda service manual and the owners manual.) I found that throttle cable was way out of adjustment, the fuel screw didn't have an o-ring or a washer and the pipe was loose to the head. Actually the header nuts were rusted solid (not tight to the flange), and the studs screwed right out. Oh...and no gasket either. Several items contributing to a VERY lean state.
I did check valve and decomp clearance and all were right in the middle of tolerance. Actually, decomp was a little high...so I brought it back to .014. Compression on my Bosch tester was low at 53 psi...low I know. Rings could be shot.
So...I ordered all the parts that I could think of and left town for work (my job takes me away from home for a few days a week). My plan is to attack it Friday evening and all my parts should beat me home.
I also ordered a fuel screw from JD Jetting (love being able to turn them by hand).
So...my hope is that after I clean the carb, put in a (correct) fuel screw, actually tighten the carb in the boots, SECURELY fit the pipe to the head (and replace all exhaust gaskets) that I will have a running CRF450X for $600 plus $100 in parts.
I'm no stranger to turning wrenches and dealing with previous owner screw ups and neglect, but I'm really hoping this one turns out to be ok. My 10 yo son switched from quads to a CRF80 last year and dad needs a two-wheeled machine to keep up!