CRF450R 2002 question...

I bought this CRF 450 3 years ago and it has served me very well, engine is strong, no weird noise, doesnt burn a drop of oil between oil change (10hrs).

Since i bought it, i have put approx 90hrs.

Using Rotella T 5W40 Synthetic both sides.

I do some wood riding, running from 1st gear to 4th most of the time. Cruising between 4000-5500Rpm (Digital RPM), sometime up to 6500RPM (Wheelie). Once in a while in 5th gear at 5500RPM during half mile stetch.

With the type of riding i do, should i consider rebuilding the engine.... it is running so well i just cannot imagine that it will eventually fail.

I dont know if the piston and Cylinder is original, since there is no way to check with the original owner since he is no longuer in the area...

When i purchased the bike, i did replace the intake valves (Honda Brand) and i have set the clearance to 0.004 Last fall they were still at 0.004 and i assume they are still there now.

Also i wanted to be sure that all were within specs inside the engine, so i did remove the Cylinder and piston, all was within specs, the piston skirt was almost all black.... just fading a little at the center of the skirt. Took the mesurements.... all was fine.

Now, 90hrs later.... with my type of riding.... is there a reason to beleive that a rebuild is needed ?

thanks.

please do a search. This subject has been done...a LOT!

Better to spend a little now for a top end, Than alot when the piston does decide to go!! 100-150hrs seems to be fairly normall for offroad guys. Me included. Just my 2c's

please do a search. This subject has been done...a LOT!

I would think there would be aSticky for the subject then. Maybe there is one, I didn't search for it though, lol!

Now, 90hrs later

Open it up and measure everything, as suggested in the factory shop manual. It is ten yers old and you have put plenty of hours on it since you bought it.

You can replace things if they are out of spec, and you can also check the crank small end for wear. Your bike has treated you well, so return the favor.

Youve put 90 hours on a bike you bought that was 6 years old when you bought it. Id bet there was 100 hours on it when you got it.

I bet if you listen closely...you can hear it ticking....tick tock, tick tock...tick tock...that's the fuse you hear....

i am in a pretty similar situation to you. except i put 128 hours on a bike that was "just rebuilt" when i got it. i am starting to hear that tick tock sound that shawn is talking about and i have had the bike parked for quiet a while because i am planning on doing a complete top and bottom end on it. i suggest you do the same.

PS i keep this bike at my dad's house and dont ride it because i am afraid that the crank is gona let go soon. and i found out that my dad brought it on a camping trip and let some bozo that i dont even know ride it around for the weekend. i was less than pleased...

Tic toc tic toc.... not sure what you mean.... would this be a noise caused by the piston, or crank ? Honnest, i have never noticed the tic toc sound has you describe.....

Let me know.

Youve put 90 hours on a bike you bought that was 6 years old when you bought it. Id bet there was 100 hours on it when you got it.

I bet if you listen closely...you can hear it ticking....tick tock, tick tock...tick tock...that's the fuse you hear....

i am in a pretty similar situation to you. except i put 128 hours on a bike that was "just rebuilt" when i got it. i am starting to hear that tick tock sound that shawn is talking about and i have had the bike parked for quiet a while because i am planning on doing a complete top and bottom end on it. i suggest you do the same....

LMAO! :smirk:

Tic toc tic toc.... not sure what you mean.... would this be a noise caused by the piston, or crank ? Honnest, i have never noticed the tic toc sound has you describe.....

Let me know.

he means like a clock or a bomb. time is running out.

LMAO! :smirk:

whats so funny old man? :smirk:

ah ok, thats what i thought ....

I will probably change de piston and pin this winter just for the hell of it.

Just put piston in mine after 100hrs. Old piston had very little signs of wear but a new one was just good insurance. Crank play was in spec.

Better to pay a little now than alot later.

Just put piston in mine after 100hrs. Old piston had very little signs of wear but a new one was just good insurance. Crank play was in spec.

Better to pay a little now than alot later.

have you changed the piston only ? What about the rings and pin ?

I think i will change the pin and piston... with the ring i have, i dont burn one drop of oil between oil change....

Of course i will mesure the gap and if within specs, you bet the same ring are going in.

this is not to save $$$ on rings of course, but why replacing something that is sealing perfectly, for something that might seal worse...

have you changed the piston only ? What about the rings and pin ?

I think i will change the pin and piston... with the ring i have, i dont burn one drop of oil between oil change....

Of course i will mesure the gap and if within specs, you bet the same ring are going in.

this is not to save $$$ on rings of course, but why replacing something that is sealing perfectly, for something that might seal worse...

You replace the piston as an assembly. Piston, Pin and rings all together. Hone the cylinder and the new ring will seat and you wont have to worry about it.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now