New to me 2005 crf450 maintenance tips

I had an 04, 05 and 07 CRF450:

Run Honda HP4 WITH Molly in the engine side and Rotella T diesel 15-40 in the clutch. Feel free to run what you want in the clutch, but make no exceptions on the engine side. Take the head vent tube and follow it back under the seat. There is a plastic T that branches into the air box and goes down to a capped tube. Remove the hose between the T and Air box. Take some Silicone and fill the air box nipple and the side of the T that went to the airbox. Then take the cap off the bottom and throw it in a garbage. In the event of a tip over, oil from the head will run into your air box and get sucked into the carb..... not fun. The cap on the botom Iis an EPA thing, if you tip over a few times and forget to drain it, it will again, back up into your airbox.

Keep the stock header, it's fantastic, and buy a White Brothers or FMF slip on.

Get a fuel mixture screw for your carb. Put your bike into second on the track and Rev it to the limiter. Make a 1/4 turn change and repeat. That easy to change your FUEL screw and your carb. Don't forget it's not an sir screw. Opening it up supplies more fuel, not air.

Any idea of the time on the bike? Valve clearance and check the cam chain would be a smart thing especially when not sure of the time and how hard it was ridden.

My 07 crf450 just had a cam chain adjuster fail. For $50 put a new one on it.

manual cam chain adjuster, the crf450 has a smaller engine oil capacity than other 450s so change it every 5 hours (get an hour meter if you dont have one) gut the stock valve breather system, i ran a different hose down under the engine. air filter every ride etc.

those carb honda 450s are monsters i love them.

Keep that thing forever

I own one of these and it has been a great bike from new. The only issue is the valves. I replaced the OEM valves and springs with stainless units, but they lasted a few years. Then I went to a completely new APE head. This is a new casting with much better ports and valves than the oem unit. It has now lasted 5 years without even a valve adjustment. This was the best investment I ever made in this bike. It was lower cost that having my old head rebuilt.
http://www.bigborethumpers.com/newheads.html
I use Shell Rotella T6 5w40 oil in both sides and I have a Rekluse EXP clutch in it too.

Paw Paw

FYI: About 99% of the OEM cam chain adjuster failures are due to the cam chain being worn beyond specks and thus the adjuster over extends and then fails. I don't recommend a manual adjuster. Plan on installing a new cam chain with each piston change.

Paw Paw