CRF Head Valve Wear Fix Complete Rebuild! Retains 100% Hp 250 450 Non EFI

Description

Why buy a new head and end up with the same valve wear problems.
Fastheads specifically designed the "Xtreme CRF head package" to eliminate intake valve and exhaust guide wear problems associated with carbureted uni-cam CRF’s. We have been updating and incorporating new technologies starting from 2004 to reach our ultimate goal. Reduced valve shim adjustments while maintaining maximum power with greater reliability. The original and cheaper fix was to replace the stock titanium intake valves with stainless. Stainless steel valves are 70% heavier which reduces power, revs slower, has a greater tendency to float, requires heavier valve spring pressures and adds stress to the rest of the valve train. Remember, these bikes were engineered to turn 13,000 RPM. Our Xtreme Ti package reduces wear and actually increases power and reliability. We still offer a more economical stainless valve head rebuild package starting at 9 but only suggest it for lower RPM trail type riding. We also offer two other packages for amateur and Pro racing depending on your needs. All packages are offered new or you head rebuilt.
Over time and with extensive testing and data logged from desert racing along with several heads tested in the Baja 1000 and hours of motocross racing, we found the following to be the best combination of parts and precision machining methods to accomplish our goal. Stock intake seats are replaced with A25 Beryllium copper. They transfer valve heat faster are less abrasive and will not crumble like the stock powdered metal matrix seats. We tried using other variations of non-toxic Beryllium in Copper seat materials but they were to soft and yielded to pounding out over time. Next, we use the highest quality mil spec titanium valves with a chromium nitride (CrN) Particle vapor applied (PVD) diamond like coating (DLC). This is a NASA engineered technique and is an extremely wear resistant metal chemical coating vaporized into a gas, and applied through electrolysis to the precision ground valve in a perfectly uniform diamond hard micro layer. This seat and valve combination along with a correction in spring pressure results in an extremely long wearing and reliable solution for race or trail. The company that builds these products for Fastheads also supplies FI racing, aero space and the military for hi-tech solutions.
It wears so well we even give it a life time limited wear guarantee.
The CRF’s exhaust valves are actuated by a rocker arm which creates a bit more stress on the valve stem, Honda opted to use a Stellite steel valve which is wear resistant and stronger than stainless or titanium. After extensive testing we decided to stay with the OEM exhaust valve. The exhaust seat material is compatible with the stock exhaust valves so in order to save your cost we cut and re-shape a new seat profile after replacing the exhaust guides. The exhaust guides are worn oval on nearly every CRF head we get in for service. This is due to the rocker arm action, heat and guide material. We use bronze manganese guides which are self lubricating, transfer heat faster, can be run at tighter clearances and are much more resistant to cracking than stock. High flow rate multi angle seat face profiles are cut using our Rottler SG7 seat and guide machine. Seat concentricity is a major factor in valve wear and has to be under .001" and measured in tenths of a thousandths with a concentricity gage. Who has one of those? We do. A human hair is .002". Old school automotive hand cutting, lapping or grinding methods can’t accomplish this degree of accuracy and will not work on small valve stem race heads. Titanium valves should never be lapped. This package also includes bowl porting which blends the seat entrance to the port casting up to the guide area. As a side note: Fastheads supports the technology of the uni-cam CRF head and believe it to be the best for off road racing. Current technology and materials can always improve the original design if needed. For pro racing we offer Beryllium seats and Ti valves for the exhaust side also. Call for a quote and servicing requirements for pro racing heads.
Actual Parts List:
A25 Beryllium Copper Intake Seats, Bronze Manganese exhaust guides, Del West CrN PVD coated Ti intake valves, Stainless exhaust valve either Kibblewhite or OEM Stellite, OEM or upgraded springs on certain models, viton guide seals.
Labor List:
Tear down, soda blast and inspect head.  Machine out intake seats and install BeCu seats. Install exhaust guides and ream to size.  Cut all seat faces. Blend / Port from seat to guides.  Assemble new valves and check stem height and final vacuum inpection.  Adjust valves shims if requested for .
Fastheads.com is the one stop shop for dirt bike cylinder heads, and valve train components.  We machine, service, modify and repair motocross heads with the latest high tech equipment.   Old school methods of seat re-facing will not work on these new high RPM heads!  Our primary goal is incredible reliability and reduced valve wear while maintaining full power.  We do this by using compatible alloys, special hard DLC valve coatings and precise machining for perfect valve to seat concentricity.  To suite your needs, we offer several options including economy stainless steel for trail to full on race packages.
See last picture for CRF options menu.
(lifetime limited wear warranty for this extreme package only)
If the intake valve shims need to be reduced more than 3 sizes form the size installed after the break in period you can send in the head for free servicing.  Includes intake valves, seats and labor for the lifetime of the head to the original owner of this repair only.  this does not warranty against heads damaged due to broken parts, timing issues, overdue valve adjustments, sanded motors, oil problems etc.  Head must be accompanied with the original dated and signed policy you received back with your rebuilt head.
Why buy a new head or even a valve job and end up with the same results?  Your probably reading this because your bike is hard to start, lost power and needs frequent valve adjustments.  This is our most popular CRF head package and is the cure
and upgrade for eliminating premature intake valve wear and solves all other problems inherent in the CRF heads.
Your head
will be returned ready to bolt on with all new valves, springs, seals, intake seats, exhaust guides, seat blending / bowl porting, professionally assembled and vacuum tested.  9package for the CRF250 04-09, CRF450 R and X thru 08 only.  This is the correct repair compared to installing heavy power robing Stainless intake valve kits.  Spend your time riding instead of adjusting valves and kicking a hard starting bike.  CRF250 rebuild, CRF450 rebuild
The CRF problem and solution:
The intake valves wear out prematurely in the CRF's because the seat material is not compatable with the OEM Titanium valve.  The OEM stock titanium valves have an oxide coating rather than a special Chromium Nitrite hard coating used on titanium to reduce surface wear. The stock iron powder seats are abrasive, micro weld and have poor heat transfer properties and tend to corrode much faster than Beryllium Copper seats.  Once the shim size is reduced more than 2 sizes the thin protective coating on the valve is diminished and wear accelerates at a much faster pace.  If the valve is not replace immediately it rounds out the seats.  If new valves are installed on the rounded seats they will wear out even faster than original. The original fix was to replace the valves with the 40% heavier Stainless Steel which are more
compatible
with the stock seat material.  Unfortunitly heavier springs are needed to control the stainless valves.  It reduced the time between adjustments but also reduced the power by up to 2hp and reved slower and put a strain on the other parts of the valve train including the stock seats.  OK for trail riding but not the ideal setup for racing at higher RPM.  Honda and all the other motocross manufacturers use Titanium for this reason.  Honda's CRF Unicam is a great design utilizing less space and weight but does have one shortcoming.  The exhaust uses a rocker arm that puts a slight lateral rocking action on the exhaust valve stem which requires a stronger valve stem.  This is the only reason they use steel exhaust valves.  Unfortunately this rocking action wears out the exhaust guides extremely fast making it near impossible to cut a concentric seat face.  The exhaust valves don't seem to loose their adjustment but do corrode and pit requiring the seat face to be cut.  We use bronze manganese exhaust guides for tighter tolerances, faster cooling of the valves and less prone to breakage.  The stock exhaust seats are more compatible with stainless steel so we don't replace them unless they have been cut to deep or have decaying on the OD.
We can also supply all your top end needs including gaskets, pistons, cams etc.
CRF Motocross valve trains come with Ti intake valves for a reason!  They produce 2 to 3 more hp and rev faster than stainless steel valve setups.
If you have decided to go with steel valves and heavier springs for
wear ability
and lower cost (which we sell in our ebay store) you will loose more power than you can gain back from porting or cams.  If you what to maintain maximum power, RPM and acceleration you have to use Titanium valves as originally designed.  Especially on 250cc machines.   Honda only use SS exhaust valves due to the extra strength needed from the rocking action of the rocker arm.  We use Ti valves and lighter springs on the exhaust for full race needs but they are expensive and need replacing more often.
Send your heads and engines to:  Fastheads.com 1141 E 540 N #6, Saint George, UT 84770
If we find any other problems in your head we will estimate and give you a call.   This package is the same price for CRF250R, CRF450R, CRF250X and CRF450X
Please note:  Modern valve faces can not be cut due to the hard facing.  For this reason we only assemble with new valves.  We offer a wide variety of valves in stainless or titanium, OEM and Manganese guides, guide seals, gaskets, and valve seats, pistons and cams to match your needs.  If you want an endurance or the Ultimate race head we can build it.   Dealers and race teams are welcome.
We use the new race developed and proven Rottler SG7 seat and guide machine specially designed for accuracy and tooled for the power sports industry.
Please check out our ebay store for motorcycle tools, rebuild kits and rebuilding services.
We operate one of the largest mail order style service for complete engine, transmission and head work for off road race bikes.  It's our specialty so we can save you money and headaches.  See us at the WORCS races and other events around the west.   Brent Kirk has raced and has been involved with the technical aspects of engine building for the last 39 Years.  All of our employees including my sons are active racers and proven technicians.  As the old saying goes:  We eat, breath, sleep, dream and love dirt bikes.
On Apr-05-08 at 17:49:47 PDT, seller added the following information:
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