Timing a Boyer

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Anonymous

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I cannot find in my notes what's the best timing for a non digital boyer on a 850 MK2.
Anyone has this number ready? (wih the timing marks and with the piston position).
Thank you
Philippe
 
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Thirty one Degrees BTDC Points are 28 degrees. You can play with up to 35 degrees if you like fast. The static setting for Boyers is done at TDC but the required light timming is strobed at 31 typical. I have made sure of the mark on my rotor relitive to the gadge lines inside the primary cover and found them to be about 3 degree inacurate this is done with a dead stop tool and a degree wheel and is worth your time. So when my line says 34 degrees it's at 31 degrees. These bikes will run way out of time but having it right sure helps with all other systems. norbsa
 

Anonymous

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That should be 31 degrees at 5000 RPM. And it is imperitive that you verify that your timing mark on the alternator is correct with respect to the degree indication on the fitting attached to the primary cover. I have seen these off as much as 12 degrees.

Randy
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Boyer timing

Randy,

If an alternator rotor timing mark is off by 12 degrees the center has likely separated from the magnet and spun. This is common on the non welded rotors that were put on the 750s.
 

Anonymous

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Interesting thought. There was no indication of an alternator rotor problem on the ones I checked, but I suppose the rotor outer ring could creep around the center hub without causing a catastrophic failure. Is this a press fit? At any rate, every Norton owner should do a degree wheel check of the rotor mark once before performing a strobe timing of the bike and again any time the rotor or outer cover is replaced. I have checked several for myself and friends, and all have been off by at least 3 degrees. My own was off 7 degrees.

Randy
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Timing Marks

If any of you have had experience with 351 cleveland motors, they will do it also(rotor slip/harmonic balancer outer ring). A lot of engines no doubt have the same problem.

This type of problem cropped up years back for me now.
Not knowing what was the problem at first(23 years ago), I left it with "professionals" for a day. I had timed the engine by ear, that is, lettting it ping & then backing it off until it didn't ping. They charged me without finding the problem themselves.

They checked everything else but..............

Having a top dead centre tool was how I found the problem later that night. The "outer ring" had moved by 17 degrees.

So, I guess the moral is...do not trust timing marks...they should be checked with the correct tool/s.
 
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