2007 WR450 op end rebuild parts

[jentzschman]

I just bought a 2007 WR450F and wanted to start buying parts a little here, and a little there so I can have all the parts ready when I need them, and so I don't have to buy it all at once. 

 

My question(s) is:

1) What parts do I need for a top end? I know I will need piston kit for sure. I also will probably do SS valves (with the SS specific springs) swap at that time. What about spring retainers, stems, seats, lifters (buckets) etc...

 

2) Is there any special process to swap in SS valves/springs? If so, is it the lapping process?

 

I think those are my major questions right now. Thank you. 

[FORMA MOTO]

The stock OEM valves and valve train parts are you best choice. There is no need to change them. They work the best. Same thing as on the YZ line.

You need to have your seats professionally re-cut when you change your valves

Do not attempt to lap you valves or seats, as you will damage them.

 

What makes you think you need valves?  

[jentzschman]

The stock OEM valves and valve train parts are you best choice. There is no need to change them. They work the best. Same thing as on the YZ line.

You need to have your seats professionally re-cut when you change your valves

Do not attempt to lap you valves or seats, as you will damage them.

 

What makes you think you need valves?  

Nothing makes me think I need new valves, just looking to the future. I was hoping to swap to SS valves as I her they last much longer and MUCH cheaper then OEM valves. 

[FORMA MOTO]

Nothing makes me think I need new valves, just looking to the future. I was hoping to swap to SS valves as I her they last much longer and MUCH cheaper then OEM valves. 

 

On any other head, you would be correct, but on the WR and YZ, the stock valves are very affordable, and they last 500+ hours no problem.

[KennyMc]

On any other head, you would be correct, but on the WR and YZ, the stock valves are very affordable, and they last 500+ hours no problem.

+1 with this ?   I just replaced my valves last year which was the first and only time anyone even looked at the valves.  Never even had them checked in the 6 years I had the bike.  The only reason i did them was I was going with YZ timed cams from Hotcams.  I went all OEM, except the cams.....

[jentzschman]

On any other head, you would be correct, but on the WR and YZ, the stock valves are very affordable, and they last 500+ hours no problem.

RMATV they list the intake vales at 76.49 a piece and exhaust at 84.99.

229.47 for 3 intake

169.98 for exhaust

--------

~400 bucks for just valves. Perhaps I need to adjust my mentality though, I am new to 4T's. 

Edited June 30, 2014 by jentzschman

[FORMA MOTO]

It's not about price, it's about value.

400.00 for 500 hours on a four stroke is about the same as (4) pistons on a two stroke, which would actually need to be changed more often than once every 100 hours, if you ride hard.

[jentzschman]

Good point.

[FORMA MOTO]

...of course, I left out the cost of the four stroke pistons....

[jentzschman]

So other then the valves and springs, do all the other smaller components need to be replaced as well i.e. collars, retainers, etc....

 

What are the big items that are the usual when doing a top end?

[jentzschman]

bump

[redhurricane]

typical top end refresh will consist of the piston kit and while you are in there a timing chain. Leave the valves alone unless they are showing wear or have moved. I have a 2006 WR450 and only on my second top end (first one over factory). Thousands of miles on my bike, some not so nice.

Want to do SS valves? Buy a Honda.

I am not a big proponent of fixing things that are not broken, so I don't subscribe to buying parts I might not even need. Want to freshen up the bike? Pull it down, inspect wear items as you go and replace what is necessary. Do so in the wintertime when you have time to work on the bike instead of sacrificing valuable riding season time. RockymountainATV/MC is in your backyard, have treated me well for many years.

[jentzschman]

typical top end refresh will consist of the piston kit and while you are in there a timing chain. Leave the valves alone unless they are showing wear or have moved. I have a 2006 WR450 and only on my second top end (first one over factory). Thousands of miles on my bike, some not so nice.

Want to do SS valves? Buy a Honda.

I am not a big proponent of fixing things that are not broken, so I don't subscribe to buying parts I might not even need. Want to freshen up the bike? Pull it down, inspect wear items as you go and replace what is necessary. Do so in the wintertime when you have time to work on the bike instead of sacrificing valuable riding season time. RockymountainATV/MC is in your backyard, have treated me well for many years.

Great advice thank you. I use RMATV all the time! I love that place and have always had a great buying experience. 

I also do not like fixing things that do not need it, but being that the bike is 7 years old and most likely not had a rebuild, I am just looking to the future is all. As mentioned, When I get to the point of having to refresh the top end, I do not want to have to buy all the parts at once.