2003 CRF450 Ticking Noise

Several weeks ago this bike became hard to start toward the end of a day of riding. I checked the valve gap and found the right intake was tight at 0. I reset it and the bike started and ran great except there was a slight ticking noise. After 3 or 4 riding trips the ticking noise became more noticeable, so I recheck the gap and found the right intake was slightly tighter than specs. I reset it again only to find the ticking noise became much louder and was noticeable when I rode around the track. I checked the gap again (always at TDC) and this time it was perfect. Anyone have any idea what might be wrong? Background info: I replaced the titanium valves with stainless steel about 3 years ago. I have taken the clutch apart, the right-side cover, and the top end looking for possible problems but to no avail. Next, I am going to remove the left cover to see if there is something loose or amiss around the flywheel. I have checked the crank and the bearings appear to be good...turn easy, no noise.

I would appreciate some advice on this. I have searched the forum and found the leading suggestion was a defective chain tensioner; however, the tensioner is working properly.

Its a Holiday Weekend. Most people are not at their computers. I am watching the Indy 500 or I would be out and about myself!

Put a screw driver to your ear (handle End) and place the tip on your engine to pin point where the noise is coming from.

You havent given enough information either. Hours on engine, previous Maintenance (piston, rings etc.)!


for the price of a head gasket you could check out the engine better it could be the small end on the rod might have a little play , piston slappin the walls of the cylinder (it does'nt take much wear to make noise) , timing chain tensioner, ect. you can change out the tensioner with a newer one from a newer model for a up dated version 03' tensioners had some problems, mine never has(I have a 03 too) but I'v seen a few on TT really you need to get in there to find out more

It had new valves, piston and rings about 150 hours ago. We did the screwdriver trick a week ago and most of the noise seemed to be coming from the top right side. I have the cylinder, piston and head off right now and have checked for free play in the rod by inserting finger through small end opening and manually turning the engine over. It rotated smoothly with no evidence of free play. Next on the list will be to remove the left side cover and inspect fly wheel and crank free play. I also thought I might remove the valve that has been tightening and check it to see if it is bent. Any other ideas???

Sounds like its time for a full rebuild if you have already have 150 Hours on a "NEW" top end! How many hours are on your engine total?

You really need to gets some accurate measurements as opposed to "Stuck A Finger in IT! measuring!


I would say it probably has 350 hours on it. I'm hopeful the problem is something simple so that I do not have to crack open the case.

I would say it probably has 350 hours on it. I'm hopeful the problem is something simple so that I do not have to crack open the case.

The simple answer is youve probably gotten your moneys worth out of that engine. Rebuild it!


Did you set the decompression flyweight gap? I had an 03 and noticed that after a rebuild the "ticking" was louder. If the clearance is not correct I believe it can cause a "ticking" sound. Good luck.

I'll check it. Thanks for the suggestion.

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