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What isn't perfect about the MJ? It does exactly what you tell it - if you tell it xx degrees at xx rpm and xx pressure it will do it.

 

Unless either your trigger wheel or sensor are vibrating then it's as accurate as you can get it?

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Using the dissy is just a bad idea.

 

I noticed on some pictures that Craigs Charger belts were loose...Needs a tensioner.

 

Why on earth is it using fanbelts? Must slip alot!...Those expensive alloy pullies will soon wear out, far better in steel, nowt to be gained on such a small item by means of weight...everything to be lost in terms of durability.

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What isn't perfect about the MJ? It does exactly what you tell it - if you tell it xx degrees at xx rpm and xx pressure it will do it.

 

Unless either your trigger wheel or sensor are vibrating then it's as accurate as you can get it?

 

Well its only as accurate as the person putting in the numbers that's all I ment. There are no perfect curves. Plainly it removes the mechanical part of the

idiot scheme.

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I've had trouble setting the ignition timing with a worn chain.

At idle it was not to bad but at higher revs you couldn't even see the mark any more.

I'd say the scatter was at least 10deg.

Note, this was with electronic ignition in a Lucas distributor.

 

There are several effects which have effect on the accuracy of the timing.

Timing chain wear, acceleration/decceleration backlash, polygon effect of the chain, oil pump gear lash.

 

With it all in good condition and no points, my guess is you would have about 3degrees of scatter.

 

Be interested to hear of the test results if you'd do it.

 

Frederick

 

I think you've summed it up well there Frederick. Just seems a pointless(sic) exercise the whole dizzy idea, if you can fit it on the end of the crank as easily as you can on the Triumphs? :-/

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Just found this, interesting info if you want to mount the triggerwheel in the dizzy.

 

Rule: Expect 0.1% to 0.5% loss in Torque for each 1 degree error in spark timing advanced or retarded from best timing.

Also, detonation will occur with spark advanced only 3 degrees to 5 degrees over best timing and detonation will cause 1% to 10% torque loss, immediately, and engine damage if allowed to persist.

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