Cam Timing Info...

[Dave T.]

I just thought I'd share with you guys so you can learn from my mistakes. I am putting my rebuilt top end back in and this morning I had the valves hitting the top of the piston when I got set up. The trick is getting TDC mark down and lining up the marks on the cam gears. The book says that your timing marks should be straight up and down (perpendicular) with the cylinder. Now eyeballing this can lead to serious problems (like I had).

So in the Haynes manual has pictures of where your timing marks should go when your at TDC. Pay STRICT attention to where the timing mark (dot) goes in relation to the cam chain plates, I.E. in between two plates, or in between one plate. This is a real pain in the ass, especially if you have a stretched cam chain. I just did a pre compression test and the rear cylinder failed, so back to the drawing board for the head.

FYI    for all you V heads out there..    ;D

[Buffo]

it is rather easy to match the timing marks on the cam shaft (2 marks on each camshaft, one for front cylinder one for rear, so use the right ones!!!!)

Dont try to eyeball it perpendicular with the cylinder thats bullsh#t. match the correct timing marks with the index marks on the cam caps. the index marks are the raised virtical lines on the cam caps, right next to the timing marks

to find perfect TDC put a long screw driver in the spark plug hole so it touches the piston. put the pig in fifth gear and turn the rear wheel slowly keep a hand on the driver and you will "feel" the driver as it hits TDC. go back and forth a few times to get the feel of it. some times 4 hands are better that 2 at this but that depends on the other 2 hands.? look throgh the peep hole in the case so you can see the TDC mark on the wheel (there is one for the front (1T) and rear cylinder (1T2). i bet you get it perfect with the driver.

make sure your at TDC of the intake stroke not the exhast stroke. do not over tighten the cam cap bolts or you will be sorry

also... if you did your compression test and the bike wasnt at prop. operating temp your readings will be low. so it may not have failed yet. i sugjest you ride your bike for 15 or 20 minutes before you do a compression test. that will give you a true reading

Don