timing front cams
Senior Member
SuperSport
SuperSport
Joined: Dec 2006
Posts: 880
From: Victoriaville, Quebec, Canada
Bring the engine to the FT mark on the compression stroke (no valves open) and align the two marks with the head surface.
To move the cams, remove the chain guard between the two cams, pull the slack and hook the chain on the sprocket one tooth further, the chain links will form a little triangle and move this extra half link around the sprocket, repeat as necessary until when you put tension back the cams are aligned like they should.
When done move the engine by hand two full turns or more to make sure you did not mess up and put the cam in a way that will destroy the engine when you fire it up.
Here's an example for the rear cylinder, but you need to use F-I for the intake cam and F-E for the exhaust cam.
To move the cams, remove the chain guard between the two cams, pull the slack and hook the chain on the sprocket one tooth further, the chain links will form a little triangle and move this extra half link around the sprocket, repeat as necessary until when you put tension back the cams are aligned like they should.
When done move the engine by hand two full turns or more to make sure you did not mess up and put the cam in a way that will destroy the engine when you fire it up.
Here's an example for the rear cylinder, but you need to use F-I for the intake cam and F-E for the exhaust cam.
Last edited by gboezio; Aug 11, 2009 at 06:27 PM.
Senior Member
SuperBike
Joined: Dec 2005
Posts: 1,689
From: South Lake Tahoe, CA, USA
If the cams jumped, you removed the CCT while the valves were open. You will need to reference the front timing position from the rear cylinder.
The correct timing for the front cylinder is 450 degrees of crank angle after the rear cylinder (1 revolution + 90 degrees).
Remove the timing chain from the front cams, so you don't open the valves when the piston is near the top of the stroke. Locate the rear timing position, then rotate the crank 1-1/4 turns to the front timing mark, then install the timing chain, with the cams at the correct orientation.
The correct timing for the front cylinder is 450 degrees of crank angle after the rear cylinder (1 revolution + 90 degrees).
Remove the timing chain from the front cams, so you don't open the valves when the piston is near the top of the stroke. Locate the rear timing position, then rotate the crank 1-1/4 turns to the front timing mark, then install the timing chain, with the cams at the correct orientation.
Banned
MotoGP
Joined: Aug 2007
Posts: 5,942
From: Lake View Terrace, CA
If the cams jumped, you removed the CCT while the valves were open. You will need to reference the front timing position from the rear cylinder.
The correct timing for the front cylinder is 450 degrees of crank angle after the rear cylinder (1 revolution + 90 degrees).
Remove the timing chain from the front cams, so you don't open the valves when the piston is near the top of the stroke. Locate the rear timing position, then rotate the crank 1-1/4 turns to the front timing mark, then install the timing chain, with the cams at the correct orientation.
The correct timing for the front cylinder is 450 degrees of crank angle after the rear cylinder (1 revolution + 90 degrees).
Remove the timing chain from the front cams, so you don't open the valves when the piston is near the top of the stroke. Locate the rear timing position, then rotate the crank 1-1/4 turns to the front timing mark, then install the timing chain, with the cams at the correct orientation.
and the rear timing position is RT on the flywheel and the cam lobs pointing out with the timing marks as shown in gboezio post.
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