Engine Noise

[AR Larry]

My '99 750ss with 16K miles has been sitting since last fall, needing a bit of work (valves adjusted, new belts, front tire, sprockets, etc.). After triple checking the valve clearances, only the vertical cylinder's exhaust shim required removal/adjustment. Now, after changing the belts, oil, and spark plugs, I finally fired her up, only to hear a fairly loud and distressing metal against metal tapping sound seemingly originating from the front/horizontal cylinder area. The taps increase when the throttle is opened. I started it up a few times, thinking perhaps the new oil hadn't yet circulated well, but the tapping hasn't much abated. Thus far all I've done is check the spark plug gap and remove the horizontal cylinder's valve covers, and all seems well (I never removed any clips or shims from this cylinder).
Any ideas about what to check next would be appreciated.
Also, when reinstalling the front tire I forgot to remember to remind myself how the speedometer cable is routed. What keeps the cable from touching/lodging against the rotor?

[motoxxx79]

how sure are you about lining up your timing marks? did you lock your cams and crank when you tensioned your belts? it may be the piston "kissing" the valves......

[AR Larry]

Thanks motoxxx79, I appreciate the help. The horizontal was off 1 tooth. I still haven't figured out the speedometer routing. I tried a logical route, which resulted in a broken cable after about 50 miles. What is the correct angle of the cable at the wheel? I have it at about 1 o'clock, which could be too steep, as the cable broke a couple inches from the end (bottom).

[FunkZ]

I have mine about 2:30 or so. Not sure if the 99 is the same as the 93-98?

[AR Larry]

Thanks FunkZ. A picture's worth a million.

Along the lines of my origianl post, I actually didn't know the piston could contact the valves. Is this true for most engines? I thought the rev limiter was to protect the crankshaft from unequal forces if the valves couldn't keep their proper timing, but is it's primary function to actually protect the valves? Why is it necessary for the piston to travel so far up the cylinder - to increase compression and thus power?

[PSk]

Originally Posted by AR Larry

Thanks FunkZ. A picture's worth a million.

Along the lines of my origianl post, I actually didn't know the piston could contact the valves. Is this true for most engines?

Yes for most performance orientated ones.

I thought the rev limiter was to protect the crankshaft from unequal forces if the valves couldn't keep their proper timing, but is it's primary function to actually protect the valves?

Rev limiter is there to keep the engine revs under control for all moving components reasons, not just crank and valves. Everything that moves in an engine has a designed optimum speed. Ofcourse the most important thing is the crank, pistons, rods and valves.

Why is it necessary for the piston to travel so far up the cylinder - to increase compression and thus power?

Yes compression ratio ... high compression = more power. The higher the compression the closer the piston must get to the combustion chamber/head and thus valves ...

This is why valve timing is critical .
Pete