Top end rebuild??

[youngnbald]

I am new with the dirt bike scene and looking into checking out my engine on the 2003 CRF450R. I bought it used and it wasn't ridden much. I do not know how many hours are on it except what I have driven now.
I have read that the intake valves are better if they are steel and a good piston is the Wiseco. Should I just go ahead and replace the valves and piston if I am going to start looking into checking the engine over? The bike starts fine cold and never a problem restarting once hot.

I read people buy the top end gasket kit and they say not all gaskets are there. What should I be buying and from where. I found the piston kit by Wiseco online and Faction steel intake valves with heavier springs.
I have read to just replace the rings after 20 hours. What am I missing here?
Recomendations?

I looked at Service Honda but thought rockymountainmc was a better site. Where else makes buying parts simple online.

 

[youngnbald]

At rockymountainmc, I found valves by Kibblewhite Black Diamond. Should I replace the valves and would I need to have someone shave the valve seat? The way I am understanding this, the after market steel valves seldom need work done after install. Sounds like the piston alone will improve the bike also.
I read about kits not having the bearing when doing the piston? The kit from Wiseco has the piston, rings, and wrist pin. Do I need more yet?

Just looking for suggestions before I set a day aside to do the repairs and inspections. Would prefer to have all parts available before I do and not need to repeat the tear down. Any help would be great.

 

[_JOE_]

In a 450 the valve life is usaully pretty good stock. Just check the clearances and ride it for a while while keeping an eye on them.

The wiseco piston kits are nice. My bike and most 4 strokes that I'm aware of dont run wrist pin bearings. Most gasket sets don't include any crush gashets for drain plugs, but usually have a head, base and exhaust gaskets at the least. Honda actually offers top end gasket kits for alot of bikes. You can't go wrong with factory replacements.

 

[Ol'89r]

At rockymountainmc, I found valves by Kibblewhite Black Diamond. Should I replace the valves and would I need to have someone shave the valve seat? The way I am understanding this, the after market steel valves seldom need work done after install. Sounds like the piston alone will improve the bike also..

The Kibblewhite SS valves and spring kit is an excellent choice. The stainless valves still need to be checked and adjusted regularly but they will outlast the stock valves by a long way. You have to install the spring kit with the valves since the valves are a little heavier than the ti valves.

You will need to have your seats cut and possibly have the guides replaced if they are worn. A good motorcycle machine shop should be able to do this for you.

The Wisco piston is also a good choice. Go with the high compression piston for a little more snap off of the bottom. I agree with Joe, the OEM parts and gaskets are hard to beat.