Ignition Timing Question


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JustMike
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Ignition Timing Question

Post by JustMike »

I have a thread going under carb problems. But something else has been niggling at me which I`ve not yet mentioned.
When I first got the bike home, a 79 Z, I realised I had a problem as soon as I ran the engine, so the first thing I did was check the ignition timing.
The trigger points did not match up exactly, so I tried to adjust the back plate holding the pulsers.
Strangely I couldn`t adjust the plate to fully line the trigger points up. But I`m only talking about a few degrees as the points were about half way across each other.
Due to there being a misfire I bought other pulsers, just in case. These line up better, just. But the backing plate is hard against the screws turning it clockwise. Would this make my ignition a couple of degrees advanced ?
Changing the pulsers and fitting a brand new spark unit made no difference.
Now what niggles at me is. The backing plate adjustment being maxed out implies the timing might be wrong on the primary shaft. But I have no idea if the engine has ever been opened. Being that it has only had one owner from new there is a possibility I could find the original owner and ask him. The bike originated from Pennock, Minnesota.
I noticed that the generator housing, not the cover, is black. So some work has been done on the engine. I just don`t know how much.
My question is. The timing between the crank and the ignition pulsers might be out at the primary shaft.
Am I correct in thinking that as long as I`m able to set the timing statically and everything lines up, there should be no problems.
The engine starts first time. Ticks over at 1000rpm when warm. runs well up to around 4500rpm then by 5000rpm I hit a wall where the misfire has kicked in. It clears sort of at around 7500 rpm and screams to the red line.
Any help or advice on this will be greatly appreciated.

Mike

daves79x
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Re: Ignition Timing Question

Post by daves79x »

I’d say for sure the cases have been split and the primary shaft installed out of time. Have see this several times. Cases have to be split to correct. It won’t be 100% right until you do.

Dave

JustMike
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Re: Ignition Timing Question

Post by JustMike »

Not what I wanted to hear Dave, but kind of expected.
I have a few other things to try first though before I go down that road.
But I think in the meantime I will try and find out a bit more about the bikes history. At least with having had only one owner from new I should with luck be able to find out something.

Mike

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