[tngoon]

Just gota 2006crf450r last summer and the head is pretty worn I put 2 new ss kiblewhite intake valves and still had the same starting when hot issue and having to use small shimms also one of the threads to hold the cam is stripped and so is the one to hold the cover on(last owner was a jack a) anywayd I found miller atv mechanincs which will recut seats for around 150 but i don't know if its worth just buying a whole new head I found a new oem for 300 to my door I can fix the stripped threads just lookin for some opinions.I just came from 2-strokes so still learning some tricks

[riddler9]

Not sure what you are getting for those prices, but they are so low that I am guessing that is not the full story.

Off the top of my head (no pun intended), to buy a complete new head (with valves, seats, etc) for less than $600 get me thinking something was up. $800 if you were going to have some work done (blended seats, etc.). I am assuming the $300 is just for an empty head.

Having said that, if all you need is to have the seats cut then sending the stock out is going to be cheaper than new, but still more than $300. A reputable shop will likely inspect your head for free (you pay shipping) and give you an honest assessment. Once you find out what is really going on, make the decision.

[crfsonly]

One of the advantages of a new head is you can get the improved '07 head. It offers better performance and is bolt on compatible with your '06. Whenever you install new valves you need to have the seats cut to get the most longevity from the new valves. If the seats have been cut before and depending on what tooling was using to cut them you may not have enough seat to cut and still maintain the proper valve stem protrusion for clearancing the valves. If this is the case then the seats would have to be replaced. When you get to replacing the seats then you are in the new head price range. If you are not installing titanium valves then a new head should be considered. Even though new heads have factory cut seats when we install new valves in a new head we still do our CNC performance valve seat cutting and blending for each valve installed. This maximizes valve longevity and seal and increase flow above the valve guide. Because we use a NEWEN CNC machine we are able to cut the seats to perfection without removing much seat material. However, you can still get a new head and install new valves without cutting the seats.

[tngoon]

Yes it is a empty oem head for $300.I figured I could use the springs off of the head I have now there for ss valves and are in good shape and I have a new set of intake valves and can get kibles for 60 a set without spings.then get seals and new keepers and I wud still be pretty cheap.

[crfsonly]

i guess i just don't have the eyes to look at valve springs and determine if they are in "good shape".

[tngoon]

Well meaning they have not had too many hours they are the first set of ss on the intake and the valves they came with are not that worn ita mostly the seat being really shallow and worn.feel free to correct me if im bein stupid like I said just come from 2strokes and these bikes are allot more sensitive then say a car motor.

[crfsonly]

while i am also a fan of reducing repair expenses i'm not a fan of doing it at the potential risk of dropping a valve. dropping a valve will cause very expensive damage. so, i just won't reuse old valve parts from another head. if the previous head had bad seats then the valves you are transferring over will likely have some wear that will not be compatible with newly cut valve seats. so, you could prematurely wear your new seats while the durability of the KW valves will be shortened. the springs may be good to use but if they won't control the valves at higher RPM's (read: valve float). cotters (keepers) wear with the retainers. so, reusing old retainers with new cotters may be ok but it can compromise the cotters. we've seen head with split cotters in similar situations. but none of this is known until something lets loose or rides on for hundreds hours. so, it's a gamble.