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General Category => Modifications => Topic started by: ccsct203 on May 01, 2011, 07:38:43 AM

Title: Cam Timing
Post by: ccsct203 on May 01, 2011, 07:38:43 AM
I have a set of Megacycle cams 268x2 I have been running all of last year with shim under, ape springs and retainers.. on and on.
The slotted cam gears are set to the oem cam timing position. I tried to set the timing to the megacyle specs but to find TDC for the piston you have to rotate the engine "backards by hand".
I tried to do this but couldn't.
What am I doing incorrectly?
The bike is awesome from its  1100cc to the 1200cc with wiseco pistons, mikuni flats and cams.
Any advice would be helpful

(http://i41.photobucket.com/albums/e299/ccsct203/043.jpg)

(http://i41.photobucket.com/albums/e299/ccsct203/HPIM0020.jpg)
Title: Re: Cam Timing
Post by: Marsh White on May 01, 2011, 10:09:44 AM
Did you take out the sparkplugs?
Title: Re: Cam Timing
Post by: SlowOldGuy on May 01, 2011, 12:56:04 PM
Why do you have to rotate the engine backwards?  You should always rotate the crank in the normal direction when setting cam timing to avoid getting any slop in the cam chain.

You can use a dial indicator to find TDC.

DavidR.
Title: Re: Cam Timing
Post by: RichBaker on May 01, 2011, 01:40:41 PM
Quote from: SlowOldGuy on May 01, 2011, 12:56:04 PM
Why do you have to rotate the engine backwards?  You should always rotate the crank in the normal direction when setting cam timing to avoid getting any slop in the cam chain.

You can use a dial indicator to find TDC.

DavidR.

When finding TDC, using degree whl and piston stop & dial indicator, the crank is rotated both directions...... It's the only accurate way to do it.
Title: Re: Cam Timing
Post by: SlowOldGuy on May 01, 2011, 03:40:19 PM
Rich, I disagree that "it's the only accurate way to do it."

I use a dial indicator and take reading on the degree wheel when the indicator shows 0.05" before and after TDC.  I then zero the degree wheel between these 2 readings.  How is that less accurate?

DavidR.

Title: Re: Cam Timing
Post by: RichBaker on May 02, 2011, 07:12:13 PM
Dave, you didn't mention the degree whl in your previous post, I got a little carried away and put in both piston stop and DI.... either will work, you DON'T need both. The degree whl is where the accuracy comes from....   :drinks:
Title: Re: Cam Timing
Post by: SlowOldGuy on May 02, 2011, 07:24:19 PM
Peace Rich!  Thanks I thought I might have screwed up my cams for moment there.  :-)

DavidR.
Title: Re: Cam Timing
Post by: fj1250 on May 04, 2011, 06:10:05 PM
I was building enough engines for a while that I took an old alternator, gutted it, had a nut welded on the end!
Slip it in place and you can easily turn the engine in either direction.
Made cam timing a breeze.

MC