Adjusting valve clearance

LOUD MOUSE · Post by **LOUD MOUSE** » Thu Jul 01, 2010 9:52 am

I think ya will find the reason the cams rotate over is that the left side cams are under pressure from the cam followers which are opening valves on that side while the right side is at TDC compression. .........lm

phactory wrote:LM,

That is how my Clymers reads for the valve adjustment, and when I say spin the motor to the LT, I do mean only 180 degrees from the T mark. But first you have to make sure that both of the right cylinder valves are closed. It seems like the motor wants to fall through the adjustment point, which to me means that I am still off one crankshaft rotation.

Thanks, Phil

teazer · Post by **teazer** » Thu Jul 01, 2010 2:29 pm

One simple trick you might want to consider is to remove both spark plugs first and as you turn the motor to TDC, look down the plug hole and see that both valves on the side being checked are closed.

The motor does tend to auto-rotate as the valve spring pressure tries to close the valve and actually forces the rocker arm to move and that in turn rotates the cam and hence the crank as LM explained above.

As you rotate thr motor, you can see the valves open and close and just after BDC the intake valve should close as you move towards TDC on the firing cycle.

phactory · Post by **phactory** » Thu Jul 01, 2010 6:42 pm

Thanks for the tips! After talking to Ed today on the phone, I realized my problem was that I tried to treat the Superhawk Motor like one of my BMW Twins. BMW Twins have a 360 degree crank and use a wasted spark. So when you need to adjust the valves you set the engine at TDC, and spin the pushrods on the engine and one side will be ready to adjust, then you spin the motor another 360 degrees and adjust the other side.

Now the Superhawk has a 180 Degree crank, which completely threw me off, plus I tried to adjust the valves like it was a BMW twin, which we know it isn't even close!

So what I found was the easiest way is to take off the rotor and the points covers. Set the rotor to the "T" mark, so that it looks like the first picture. Is the mark on your cam pointing straight down? If so, then you are ready to adjust the RIGHT SIDE valves. If the mark is at the top, you need to rotate the engine another 360 degrees so that the mark on the cam is pointing down, like in the second picture.

Set both valves to 0.004" or 0.10 mm.

Now rotate the engine 180 degrees and set the rotor to the "LT" mark, as in the 3rd picture. The mark on the cam should be pointing to the left, 90 degrees from where it was. This is because the cam spins at half of the speed of the crank, or in other words it takes two full revolutions of the crank for the cam to spin one revolution.

When the motor is set up as in the 3rd and 4th pictures, then it is ready to adjust the LEFT SIDE valves. Also set them to 0.004" or 0.10 mm.

You will need to spin the motor another 540 degrees to get back to the point where you can check the right side valves, which I suggest doing.

Sorry if this is stuff that most people on this board knows already. It has been an interesting day of trying to figure out what the hell is going on with this adjustment process! Thanks to Ed for talking me through it. Now onto the points!! :-)

Thanks, Phil