Basic Camshaft adjustment instructions

In order to accommodate the INEX rule regarding cranking compression a camshaft timing adjustment may be necessary.

By retarding the intake opening timing the static compression will stay the same while lowering the cranking compression.

The first step is to check your existing compression. Warm your engine up. Pull all spark plugs, using some good anti seize screw in your compression tester. INEX uses the MAC tools CT-25 compression tester with the 12mm adaptor. Readings can vary considerably so make sure you have a quality gauge that has been well taken care of.

With carbs at full throttle crank your engine 10 to 12 revolutions and read the gauge.

Once you have determined your starting point remove your valve cover. The first thing you will see will be your intake and exhaust camshafts. The Intake will be the one closest to your carburetors. Slowly rotate your engine over using a 7/8” or 22 millimeter wrench until you can see a dot in the camshaft while looking down thru the hole in the number 3 cam cap.

ADJ BOLT

CAM HOLE INTAKE CAM

Each gear will have 2 opposing slots that allow you to turn the gear on the camshaft. Loosen up the two INTAKE cam bolts using a 10MM wrench. DO NOT REMOVE, just loosen. While loose, rotate the cam towards the carburetors just a small amount (1/16”) this can usually be done by using a 7/8” or 22 MM wrench on the hex part of the cam, right next to the gear. You can watch the dot in the cam hole to determine how far you have turned the cam.

Cam Gear ADJUSTMENT SLOTS

CAM GEAR ADJUSTMENT BOLT

Retighten the camshaft bolts, rotating the cam if necessary, and reinstall the valve cover.

Once again check your compression. If you are not under 165, move the camshaft on the gear again and recheck.

Take small steps till you reach the desired compression.

Once you have achieved the correct compression position a clean rag under the cam gear, carefully remove each bolt one at a time, being careful not to drop the bolt, and apply red lock tite to the threads and reinstall. Remove the rag and torque each cam gear bolt to 186 inch pounds or 15 foot pounds

Reinstall your valve cover and head to the track.