2005 Honda CRF 450 R - Page 2 - Answered Questions & Fixed issues

there is really only two ways for oil to enter the oil (1) is the oil and water seals fitted on the water pump impellor or (2) the other is head gasket leak
the most common on MX bikes is the oil and water seal at the impellor (water pump)
if your not to mechanical minded then both of these issues you would be best to take to dealer to rectify as they bit tricky to do with out experience.
if you are mechanical minded then either problem is fairly cheap to fix about $25 for the oil water seals or about $70 for the head gasket
let me know if you want me to elaborate on either issue
good luck regards Jamie

Check the tension on the timing chain - make sure the timing chain tensioner is working correctly - it sounds like the exhaust valve (or possibly the intake valve) may be partially open when the plug fires. Make sure the chain isn't off by a tooth or that the timing chain isn't too stretched.
Run a compression check too to make sure the exhaust (or intake) valve isn't leaking.
A really good test for a leaking valve when the head is off, is to put some form of solvent into the top of the valve area and see if it leaks through (I use carb cleaner for this, it works well for detecting leaks).
If the valve is leaky, it may need to be lapped.
Valve lapping tool is very cheap (it's basically a wooden handle with a suction cup on either end) and valve lapping solution is easy to find too (I think I got mine at www.bikebandit.com).
It's best to try and find 2 in 1 lapping solution - it will have course solution in one end, and fine in the other. Place the solution around the valve seat, and suction the tool to the valve, and spin the valve back and forth in the seat vigorously for several minutes with the course solution, clean the seat and valve, and repeat with the fine solution.
Ultimately you should be able to pass the solvent test with only finger pressure on the valve (without the valve spring in place) - but at the very least you must pass the test with the spring connected.
It's best to check all your valves.

If all the valves check out, then it's time to look carefully at the compression rings and cylinder wall.
If there is evidence of scratching (not gouging) have the cylinder HONED (not BORED), and get a new set of stock compression rings.
If the cylinder wall is gouged, it may need to be bored, and you'll need to get the appropriate oversize piston and rings.

I can email a PDF of the page in the factory service manual that shows how to time the engine. You will need a timing light. The file has two line art drawings and two photos. I can call tomorrow to get your email address. I can then email you and attach the PDF file. Below is what it looks like. The Fixya system doesn't handle PDF files. Please rate my answer. Thanks. .

Right behind the cylinder, on the top of the right center case half is a hose. The hose is to vent the buildup of pressure from piston blow-by into the gearbox. The vent hose is routed to the rear of the gearbox and the oil is probably winding up on the skid plate. Does the engine smoke a bit? It sounds like it's time to bore the cylinder and install a new piston and rings.

check all the wiring on and around the coil make sure theres a connection between the coil and the sparkplug and last check to see if your coil is working perfect

Good Luck.

Chances are the float needle is stuck closed. Remove the float bowl and spray carb cleaner at the float pin while gently lifting the float then releasing the float to drop freely. Do this several times until the gas starts to flow when the float drops downward. Check also that the gas is turned on and gas is in the tank.

www.behonda.com

Thats where it is.
Before you take it out,blow some compressed air down there to help clear any dust and **** that may be down there.If you have a look on the side of the head,there will be a small hole about the thickness of a match.Make sure that is always clean as it is a drain for the sparkplug recess.Hope this helps

i used to ride motor cross and i had a bike shop i indiana honda shop has fork oil . i dont know how many cc to use the honda shop should tell you but i will look on line for it and email you back my e mail is [email protected]

Has your bike been jetted and tuned to suit new exhaust ?? if not its more than likely your problem.
If it has been jetted to suit you can try adjusting your fuel mixture screw richer or leaner to see if that makes any difference

Check your pilot jet is not blocked or try adjusting your idle screw for the idle issue and it sounds like its runing lean which can also make it idle low and rough and will cause it to pop and backfire. Dont think it has anything to do with your hot start cable that will make it run it run better if its running rich but your is doing the opposite

Hello and welcome to Fixya! Well first lets start at the tank, remove your fuel hose and make sure your getting fuel out of tank. Next check your line from the petcock to carb. If here is no fuel coming out from this point inspect your petcock for any obstruction, try blowing air threw it. Its either something plugged inside tank, or your petcock. Now if you are getting fuel out of petock to carb, remove carb and inspect where the fuel line hooks up, remove float and float needle and then blow air threw it. If its clear then check your float height and make sure its adjusted to spec. If you need further assistance please feel free to let me know. Thanks and good luck! Cycleworx157

Remove the brake rotor cover. Remove the axle nut. Loosen the four bolts that clamp the front axle. Pull out the axle. (The brake caliper can stay put.)

Engine oil:
Fill the crankcase with the recommended oil. Capacity: 0.73 US qt (0.69L) at oil and filter change Tansmision oil: Fill the crankcase with recommended oil. Capacity: 0.62 US qt (0.59L) at oil change.

crf honda's run titanium valves which wear out very quickly if valve clearances not checked very regularly. what happens is the valve wears on its sealing face and clearances close up and then valve rides and looses compression,much like a leaking tap. bike will make more compression and valves will try to seal when warm. i probably rebuild one of these bikes a week with this problem. get it to your dealer and have clearances done. you can get stainless steel valve conversion kits which are much cheaper than honda titanium valves.

there is a plug for gearbox oil and 1 for engine oil

there should be a sticker on the upper right side of the frame that says the year. at least on my 05 it does. the 2005 has a different body style also so look for that. you could also look at parts on it and see if any of those parts have dates on it but i think if it all comes down to it and you cant figure it out, take it into a honda dealer and have them check it out or a motorcycle shop. This probably didnt help at all im sorry but thats all i can think of.

personally i like to change the oil on my crf450 every 3-4 rides and if im riding it hard or cleaning the engine out, i do it every ride. The gear oil i do about every 6-7 rides unless im riding it hard then i do it less. Everybody will have there own opinion on how and when you should do it.. Some do it after every ride but i think thats a little obsessive. I like to use amsoil 10w-40 for the engine oil but i think any synthetic will do. I used to use the normal honda oil but i switched to synthetic and it cleaned it out a lot and ran better to be. I use a semi synthetic on gear oil and dont find anything wrong with it. im not an expert at this at all and maybe im doing this all wrong but whatever it runs fine and works fine for me.. as long and you make sure the oil is clean, air filter is clean, and keep the right amount of oil in it it will be fine. But i would highly recommend using a synthetic oil for the engine and probly a semi synthetic for the gear oil to reduce the clutch slipping. * also mobil 1 makes a pretty good 10w 40 as well but amsoil is 2 bucks more so i just do that. You can change the oil yourself or have someone else do it its really really easy. Also make sure you change the oil filter every time you change the oil to.

The accessory radiators offer 30%more efficient cooling, they are also lighter and stronger than standard radiators.
I know this doesnt answer the fan question, and I have seen computer fans etc fitted , but without a thermostat to turn them on and off, I have doubts about how much they really help, you also need to be concerned with current draw by the fan flattening the battery.

Clutches or crank bearrings.