technical help please

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Jan 18, 2006
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good morning all.....hoping someone can help me.....I am putting an 850 engine back together and an now installing the points advance unit. I have the timing information but can't find what the two markings on the points cam indicate.....top dead center? high point?? any help would be appreciated......thanks
 

L.A.B.

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That is the highest lift position of the cam.
 
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which mark goes to high point the squared off piece or the indentation? thanks for help
 

L.A.B.

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I am not quite sure what you mean by "high point" ?
The points cam should be rotated until the scribed mark lines up with each points heel in turn and the gaps set, preferably after the auto advance unit has been correctly positioned and tightened down.
What timing information are you using?
 
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:?: right now the timing cover is off and cam chain sprockets are set at top dead center left cylinder .....if i leave the engine in this position and put the timing cover back on....can i install the wide mark on the auto advance on the top side center position? am using working workshop manual......is there a physical starting position i guess is my question....thank you for helping........
 

L.A.B.

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Right.

There isn't a set position to just bolt down the auto advance.
What you need to do is fit the auto advance unit loosely in position and find a way to set it to the fully advanced position, there is a special washer available for this but you should be able to find a way to do this (perhaps others can give you some info?) the points backplate then has to be fitted so that the screws are central in the slots.

The engine needs to be turned back (from TDC) until the rotor mark lines up with the 28 degree timing mark. The AA unit then needs to be turned without moving the crankshaft until the points are just on the point of opening/closing (noting the correct cylinder points) and then the AA unit bolt tightened down.
The points gaps and the ignition timing can then be set. If the AA unit has been positioned correctly then there should be enough range of adjustment to set the timing correctly.

I have electronic ignition fitted to my Commando and do not actually have the points setup but that is the procedure as I understand it from the factory manual so possibly others can add extra info?
 
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:roll: thank you for information......hubby has gone to work will share with him and hope this helps......great forum....glad we found it!!
 
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Timing washer

I dug up my old self-made timing washer. It measures: ID= 0.41" (10.35mm)
OD= 0.70" (17-18mm) approx. TH= 0.069" (1.75mm) Notch= 0.69" (1.75mm) -from ID Notes: started with a washer with correct ID and ground the OD down for points and visual clearance. Not critical, just want to be able to fit the points plate assy over the advance unit and see the rubbing blocks when rotating. The notch is for seeing the timing mark in the face of the advance cam. BTW, the mark is the line, NOT the square cutout. Make the notch with a file or dremel. What is also needed is a bolt and nut with the thread size matching the internal thread of the advance. I've missplaced my bolt, so don't have size, but you want as much thread engagement as possible.
To use: Nut onto bolt followed by the washer. Thread into unit until bottoms, or nut touches. Run nut down, spread weights out, align washer notch with timing mark and snug nut down. When you have everything aligned (per the earlier post) use a small hammer to tap the head of the bolt. Eyeball the alignment to make sure things are straight. Rotate the motor to verify. If all looks good, remove bolt and washer and replace with the holding bolt. DO NOT leave the notch washer in place, or the advance will not function. ALSO: If the motor doesn't start, but coughs or backfires, try swapping the ignition wires. I have encountered bikes that were timed out of phase, and it's easier to swap wiring than to pull out the advance. Also, They tend to wear the taper press fit each time it goes in or out. Not good.
 
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