Valuable Info on CRF valves..

My 02 valves lasted a whole season (1400 miles) with regular inspections, but the clearance on one intake closed up rapidly at the end. The 03, valves, head and springs all have the same part numbers, so you guys might want to read up too?

I had several long discussion with Kibblewhite, the only makers of Stainless steel valve kits so far. Without getting technical, They said all titanium valves are kind of soft, and the honda valve seats are kind of hard, while the springs are borderline too soft. This unhappy combination means the valves can sometimes bounce on the hard seats which accelerates wear.

I found two other companies that can supply SS valves (custom) at very reasonable prices, but neither of them knew about CRF's and had the appropriate spring kits. For now Kibblewhite http://www.blackdiamondvalves.com/Default.htm is the only show in town. They are now selling only through distributors, the largest of which is web cam I think. They offer "white Diamond" valves with hard chrome stems right now, but will soon be shipping the "black Diamond" versions with some kind of hard black surface treatment.

They only sell the full spring kit for 4 valves, and say the exhaust springs are slightly stiffer as well. You can however only use the SS intakes with your stock exhaust, but you might as well use their SS exhaust too while your in there. I got prices of $32.00 per valve, and $185.00 for the full spring kit. All reports so far indicate that this completely solves the valve issues.

You do need to cut the valve seats before installing valves, and you can buy the neccesary carbide hand cutters from Neway Mfg. for a little under $200, or trust some shop to do it for you. These hand operated cutters are better than grinding stones, and are what 90% of all dealerships will use. I don't know what the going rate is for valve seat cutting, but I chose to buy the cutters. I am a Honda meechanic from way back, and won't let anyone touch my motors.

I ALWAYS freshen up the motor before each season no matter what I ride so none of this bothers me too much, but the cost was a bit high. The whole job with valves, springs, piston & rings, gaskets and the cutters cost me around $650.00

I'll forget all about it when I hit the trails this spring, and hopefully it will increase the resale value??

how about a group buy on this service. Is anyone interested in providing this service for TT members at a nice healthy discount.

I'd be interested in a group buy. Count me in.

Why do you have to cut the valve seats, the person I talk to at web cam said just lap the valves a little.

niagara power sports also sells valves specifically for the CRF. their # is (716)-791-4325 or on web at www.npsracing.com

I have one of his heads and I'm happy with it.

GStar

FHP - You might get away with lapping only, but you had to spend $300 for the parts plus gaskets and labor. Why skip this critical step? You don't positively have to change rings with a piston, or sprockets with a chain, or hone your cylinder for a new piston. All these things wear in sets, but you can sometimes get away with cutting corners. My daddy always had the perfect answer for stuff like that. "Don't confuse good luck with good practice" My intake valve seats were worn a little wider than specs, and a little rounded. The exhaust seats were pitted. I wouldn't have been able to sleep at night if I didn't cut the seats.

Gstar - Are the NPS valves Titanium or Steel, or Stainless steel. If stainless, or regular steel they will need new springs, and if Titanium, they won't be any harder than stock, and still should have stiffer springs. The stock light springs are part of the problem.

The Kibblewhite valves are also found in the new Parts Unlimited Parts Book for CRF 450's.

Woodsryder: you stated in previous thread (You can however only use the ss intakes with your stock exhaust)

If I put SS valves in my bike, I can't run a aftermarket pipe?

I can't run a aftermarket pipe?

He meant exhaust valves, not exhaust pipe.

I saw the valve kit in the Parts Unlimited book today at the Honda dealership. The price was $223, with my discount it would be $178 and no shipping. The valves were $33 sold individually. If I need them I will order through the dealership.

Dear Friends

While it is true that the Black Diamond valves and spring kit are in the new Parts Unlimited catalog ,as of wednesday they were not in stock and there was not an ETA.Cheers

One of the questions was "why cut the seats?"Because valves may be made to the same specs but they have manufacturing tolerances which even in KPM's case are tight,it still wanders.Not only is freshening up the seal(not misspelled) you're re-centering the sealing surface on the seat.It's called concentricity and is the relationship between the center axis of the valve stem and the valve seat.If it's off the seat angle will try to self center the valve causing the guide to wear faster and stem seal to fail.I set mine to no more than .001" concentricity and my valve jobs last a long time.It's also a case of while your there why not do the job.I have an '03 and hope not to have "the problem". :)

I put the SS valves in with the heavier spring kit not too long ago, without cutting the seats. I've been checking the valve clearance every 200 miles and each time I check, I'm losing .001. If I were to do it agian, and it looks like I will have to, I will cut the seats.

What is the parts number for the seat cutters?

You can get cutters from Neway MFG. 800 248-3889

CU270 60 degree cutter $58.00

CU232 30x45 degree double sided cutter $98.00

PMI4050 5 mm pilot $19.50

PMI4055 5.5mm pilot $19.50

TW505 Wrench $8.00

I got the #232 cutter with 1 3/8 body. This is borderline too big to clear the exhaust seat pockets, but I will clearance the cutter body to work. I wanted the largest cutter body for use with other vehicles. You may also be able to use the #230 body without any clearancing. it is only 1 1/4 dia. but the cutters will stick out farther. I won't know which is better until my valves come in and I try the cutters. Ask the salesman for a reccomendation.

I was told the black diamond intake valves will be shipping any day, but the distributors may still be selling the white diamond valves until stock is depleted. If you want the black ones, specify them. Unfortunately some distributors (Web-Cam) don't know the difference and think they are all black diamond. The exhaust valves are all white diamond right now, and the black ones won't be availiable for a few more weeks?

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