Wisco high comp or 480kit?

shifting

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#1
Sorry if you guys already went through this with someone else, but I would like to get some info from everyone. I've been off DRN since July. I have a 03' CRF450 and would like to get a little more out of it. Wisco has a high compression piston 12.5:1 I think. That and a hotcam or The Wisco 480 kit? How about having Eric go through the head. He did my CR250 and it was great!!!! :aj:

Anybody else dying to go ride, only to be held back by this 20 degree weather?!!! :|
 
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#2
Billy Frank (aka BillyWho) went with the stock bore high compression piston on his 03 CRF and really liked the difference. That piston and a properly designed pipe can really fill in the low end and mid-range without clipping the top end revs.

I personally like the characteristics of the 480 kit and porting best of all. It will lower the peak torque rpm by about 500-800 rpm, but for most of us the additional torque and the willingness to pull taller gears is a worthwhile trade off. The cylinder head comes from Honda in really good shape so all that is really necessary is a clean up of the throat of the ports and the area that blends in and out of the valve seats. They also respond nicely to a multi-angle valve job when it's time to resurface the seats. The only real downside to this engine is the intake valves wear fairly quickly and they can't be resurfaced, only replaced. Kibblewhite makes a stainless steel replacement intake valve and spring kit that has much longer service life and allows resurfacing of the valve in the future. The exhaust valves can usually be cleaned up and the seats resurfaced under normal use.
 

shifting

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#3
I have a Thunder Alley silencer and cerma-chromed my head pipe. I put in a Zip-ty racing fuel screw to make it easier to adjust. Went up one tooth on the rear to 13-51 gearing. I see your the one Eric has working over the 4-strokes, Rich. What kind of money are we talking for the 480kit with kibblewhite valves and springs and porting? How about turn around time?
Am I going to need to adjust my valves more often with this set up? Just want to know as much as possible before I start messing around with a stock motor. Right know I'm about 40hrs on the motor and the valves have never been adjusted. I have checked them 4 times, last week was the last time and they are still within Honda's specs!? Sorry to take up your time.

Thanks in advance Rich, Eric and anyone else that wants to give up their opinion!!!!
Ryan.
 
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#4
Ryan - You'll have to call Eric on current pricing 1-630-289-5645 .

As for the Kibblewhite stainless valves, the adjustment intervals will tend to be much longer. These valves are much less likely to run into recession problems like the OEM Ti valves do. It's a great upgrade.
 
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#6
The Thunder Alley pipe will be an excellent match to the 480 engine.