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Hey gang

I've been wrestling with the '72 450 points plate and trying desperately to get my timing right. I'm soooo close, but no matter what I do, I just can't seem to iron out some niggling coughs and splutters - using either the static or dynamic methods.

I have a feeling I'm just too ham-fisted to get this bit right, so I'm on the lookout for an electronic ignition kit - the kind Newtronic used to do. I've had a look at Boyer, but they don't seem to have a twins kit.

Any ideas for other suppliers?


Neil

BTW - I should add that I've checked and rechecked the carb settings, float heights, valve clearances and the timing plate itself is new (as are the coils and condenser . . . )
 

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A Dyna GL1000 kit can be adapted to the 450. The points cover will need a spacer under it.
Also, I guess a Yamaha XS400 electronic ignition can be adapted. On the old CB450 board there was a lengthy thread about it.
I'll see what I can dig up, or maybe someone here can add.

NE
 

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Curb Tiger... I was the "designer/fabricator" of the XS 400 ignition mod... It works Ok, but a Dyna is better and easier...Just costs more.... I don't have a copy of the "lengthy" post but would like to find one...PM me if you locate it online... Steve
 

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Hey Steve, what were the drawbacks to that mod? Compared to a well set stock points ignition. Nevermind the fab difficulties.
I think I copied the complete text to that thread...somewhere.

NE
 

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If I remember correctly, the timing advance (degree at which it occurred) was slightly different, and the trigger added a "wasted spark" to the equation.. (no biggie, but uses extra electricity)... We were going to try a different type of trigger assembly, but the group lost interest in further experimentation...........
 

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If by the correct definition of "wasted spark" you mean an extra spark occurring during the exhaust stroke, then NO as applies to a stock 450 points set-up......(remember, the camshaft turns at 1/2 the crank's rotational rate).......

GB... ANY spark on my bikes is wasted due to the dead short between the handlebars and the seat.....LMAO!
 

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Ok, as far as the stock 450 points setup there's no wasted spark, but when converting to EI there would be, correct??


GB :mrgreen:
 

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Not necessarily.... IF the trigger (rotating part) is camshaft mounted, and has only one "lobe" it will just spark as it aligns with each pulser coil (pick-up coil), but requires separate ignition coils and brain box circuits for each pulser.....
We intended to add another pulser coil to the pictured plate and run two "brain" boxes and separate coils on a 450... The advance unit contains a single magnetic trigger and the set-up shown is a stock unit from a Honda 175 single cylinder bike.....
 

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I understand ya now Steve.. BUT on the Dyna EI being used on a 450 I could've sworn there was a wasted spark during the exhaust stroke..

GB :mrgreen:
 

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Bird76Mojo said:
I understand ya now Steve.. BUT on the Dyna EI being used on a 450 I could've sworn there was a wasted spark during the exhaust stroke..

GB :mrgreen:
The Dyna does have a wasted spark what Steve was talking about is completely different ;)
 

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Allow me to clarify this seeming operational conflict.....

It has been awhile since I fooled with (what I remember as, and think was) a Dyna... (1981)... But as I remember converting them for use on the 450, we removed one of the magnets from the plastic "advance rotor" and rebalanced with a lead slug (made from an old wheel weight)..... Not 100% sure of the brand, but I know the unit was designed for a GL 1000, (which, having four cylinders but only two pulser coils would have to fire twice as often (hence the magnets at 180 apart on the rotor)..... The modified rotor would now only trigger a spark once (in each pulser) during its rotation and therefore has NO "wasted spark"...... Since the units are now installed basicly unmodified, there would be "wasted sparks" as currently used .....

Does that help ?????........... Steve
 

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That explains it better for my child-like brain Steve.. Thanks.

Now you've got me curious about my 2 NOS Prestolite EI systems.. From what I can tell they appear to be a wasted spark system as well..

[attachment=0:1oj1pjdt]S5030453.JPG[/attachment:1oj1pjdt]


GB :mrgreen:
 

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Scan the instructions, and add pics of the components...I'll tell you what I can.........
:cool: Steve
 

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They do have a wasted spark when fitted to a CB450-500 as they were built to fit ether the GL1000 or CB450-500 :D


Just looked at the rotor and the sensor, the censor is designed to see a metallic object not a magnet (although it would work equally well) and the rotor has no magnetic parts. So the rotor could be trimmed to remove one of the protruding metallic parts if you wanted to ;)
 

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I believe the Dyna uses two censors (hall effect) and one magnet as a trigger, and the Prestolite uses one censor and two triggers, still works the same.....i think :?
 

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I'm working on scanning the instructions just for people to have a look at, as I know that at least one member has a Prestolite that came with a bomber purchase, and who knows, someone just might need the intructions someday.. :D

Now if my compooter will play nice with my printer... :evil:

Rod, don't you find it odd that the instructions list using one set of slots on the rotor for the GL1000/450 and the other set of slots for the 500T?? Seems odd to me but again, I'm a thick headed mule..


GB :mrgreen:
 

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Bird76Mojo said:
Rod, don't you find it odd that the instructions list using one set of slots on the rotor for the GL1000/450 and the other set of slots for the 500T?? Seems odd to me but again, I'm a thick headed mule..


GB :mrgreen:
I just thought that it was because the unit is mounted at 45 Deg to to the CB450 one and that it would give you correct orientation to number 1 cylinder for tuning... although i could be wrong..Don't forget the all important spacer ring on the GL1000 :lol: :lol:
 

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My thinking was that the CB450 and CB500T were similar enough that you'd use the same orientation and set of slots on the rotor for installation..

I still don't understand the difference..

Me not so smart.. :roll: :|


GB :mrgreen:
 
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