03 cr450f acting up, not sure what is wrong...

Hello,

I bought an 03 cr450f about a month ago, and have put close to 30 hours on it in that time. All hours have been trails ranging from heavy sand to rocky hills. I have been changing the oil on both sides every 10-15 hours. Engine oil comes out honey, clutch oil comes out burnt, and gray.

I am using HP4 in the engine, and honda pro gear fluid (the red stuff) in the clutch.

On my ride last weekend, and my ride yesterday, I noticed that the engine has been 'easy' to kick over. Like there is not as much resistance on the down stroke of the kick.

And for my ride yesterday, the bike was hard to get started, it took like 5-8 kicks before it would start, and this was AFTER it was warm and had been riding around.

When I first got it, it would start pretty easy like 1-3 kicks.

This is my first 4 stroke, I am coming off of a yz250 so Im not sure what all these symptoms mean. And I have not torn it apart yet....I wanted to get some advice as to what could possibly be going on inside my bike.

Thank you for your help.

your valves probably need major adjustment check that first.

that's alot of time before changing your oil........i would cut it in half

that's alot of time before changing your oil........i would cut it in half

10-15 hours is not much for trail riding. I change mine every 12 hours and it comes out just as it went in

that's alot of time before changing your oil........i would cut it in half

Im not crazy hard on it, I do ride in the uppers revs when the straights come along, but for the most part it's twistys and whoops I am in 2-3rd gear mid RPMS.

And Im following book recommendations....

Any other clues as to what may be happening here? Do I need to provide more info?

--John

Check your valve clearance. Most likely you have an intake valve closing.

10 hour oil change intervals are ok if you do a lot of cruising. The tranny oil is the first to go because of the messing gears and clutch contaminants.

Cam gear side intake valve closed. Your the first one(today that is). Congrats on being the one millionth honda rider that needs valves. I did mine at 55 hrs when they went to zero.

My bike ('03) wouldn't start after 9 months of 1-3 kick starting. It got to the point where it would only start when bump started but when it was warm it was fine. The valve clearances were pretty tight and I felt a loss in compression when attempting to kick it. I finally got the courage up to take the head off and one of the intakes was so heat warped from 4 years of use that there was daylight between the valve seat and the valve. Since I knew that the valves needed to be replaced I put in a new piston, SS valves, new cam chain and a MCCT. My guess is that your valves are due to be replaced.

My bike ('03) wouldn't start after 9 months of 1-3 kick starting. It got to the point where it would only start when bump started but when it was warm it was fine. The valve clearances were pretty tight and I felt a loss in compression when attempting to kick it. I finally got the courage up to take the head off and one of the intakes was so heat warped from 4 years of use that there was daylight between the valve seat and the valve. Since I knew that the valves needed to be replaced I put in a new piston, SS valves, new cam chain and a MCCT. My guess is that your valves are due to be replaced.

Great reply, sounds like what I got going on. So, ok. Does this mean I need to do a top end on it as well? If so, is there anything else I should replace aside from what you replaced? Or would I be ok, just replacing the valves?

If not, what else should be replaced during this repair?

Great reply, sounds like what I got going on. So, ok. Does this mean I need to do a top end on it as well? If so, is there anything else I should replace aside from what you replaced? Or would I be ok, just replacing the valves?

If not, what else should be replaced during this repair?

Doing the top end would be a really good idea and smart preventative maintenance. Make sure to replace all the gaskets such as the head gasket, etc. Look at my garage for a parts list, it cost me around $600 once everything was all said and done. Your best bet would also be to send the head off to an expert and have them cut the seats and install the new valves. There are some good shops available, Ron Hamp is good, AgentSmith is also good and MXTIME is good. Follow the manual and it should give you a lot of good information. TT is also a good source for the stuff that the manual doesn't give you.

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