quick question about 450 cam swap??

24 replies to this topic
  • grayracer513

Posted January 25, 2008 - 07:37 PM


Go to your local Honda dealer instead. Tell them you want the shims to fit a CRF450 (either valve, 9.48mm diameter). They should have plenty of them on hand. :cool:

  • spc mike

Posted January 28, 2008 - 12:50 AM


ok..ok.. i know i have asked this before but i dont feel good about my valve clearance readings. when u guys check your valves do you go untill the the next size gauge wont go in at all or do you stop at witch one has just a little to much resistance??

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  • grayracer513

Posted January 28, 2008 - 07:22 AM


You can get a bigger feeler gauge under a valve than the actual clearance if you push, so that's actually incorrect. Think of what it would fee like to slide a .006" gauge into a gap between two ground parts that is exactly .006" wide.

To give you an idea of what the feel of a feeler gauge should feel like, put a metal plate, or something smooth and hard on a bench and grab your feeler gauge. Take an 6-8 inch adjustable wrench and hold it so that the flat sides of the jaws are vertical, and the rounded top of the jaw is down. Rest the jaw on the feeler gauge blade, and hold the wrench in that position by the end of the handle so that the wrench's weight is the only pressure on the blade. Pull the blade out from under the wrench slowly, and note what it feels like. That's a fair approximation of what you would feel when your clearance is exactly the size of the gauge.

Feeler gauges in the best hands are rarely so precise as people imagine them to be, and having the specs listed in the less familiar metric form exaggerates the spread in your perception. The .05 mm specified tolerance range is actually only .002" wide. The best trick is to use three different ones on anything you measure. One will be tight, one will be loose, one will fit better.

  • spc mike

Posted January 31, 2008 - 09:39 AM


well i got my bike together and all..., but when i kick it over it seems like iam catching alot of compression? it this normal or should the kick stroke be smoother?

  • grayracer513

Posted January 31, 2008 - 10:15 AM


The AD cams do not eliminate compression, they reduce it by preventing the left exhaust valve from seating for the first half or so of the compression stroke if the engine is spinning less than about 600 rpm. This cuts the cranking compression from somewhere upward of 200 pounds to more like 110-120, and allows a starter motor to rotate the engine, or the engine to be kick started without manually positioning the crank first. Push against compression, raise the lever, and kick through smoothly.

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