Timing moves

Classic short-frame models

Re: Timing moves

Postby Otis » Fri Jun 05, 2020 8:21 pm

It has the stock retard setup but I’m in the process of putting an early fixed setup to see if the worn adapter plate is causing the issues.
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Re: Timing moves

Postby Otis » Tue Jun 09, 2020 12:38 pm

I’ve gone through everything very thoroughly and still having issues. Sometimes it will stay timed for a little, other times it changes just kicking it over. I’ve never split cases before so my question is: if the gear shaft chucked the key, could happen and if it did could the key be spent but the nut still tight so no apparent lash, slop or noise would be present? Also do I need any special tools to split cases? I really like to do my own work. Most anything I have had others do, I’m not satisfied with.
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Re: Timing moves

Postby Ferrous_Head » Tue Jun 09, 2020 5:21 pm

Back on the 4th, I wrote this.

As a "sanity check" I would now set the timing by using the piston position. I don't care what your timing marks say physics over rule any timing marks. 11/16ths BTDC.

There are simple tools for doing this, cheap.

Set the timing there, That is fully advanced 45 degrees BTDC.

Do that. Start the engine and run it for a minute.

Recheck the timing once again by using position of the piston, not timing marks. Continue to ignore them.

If the timing hasn't changed this time you can ignore the timing issue and start further trouble shooting.

If the timing HAS changed you will now have to look at your valve timing.


Have you done that ?

Because if you have physically checked the piston location in comparison to your ignition timing point and that point IS changing then I would consider my last sentence again.

If the timing HAS changed you will now have to look at your valve timing.


Because if the pinion shaft is moving in the wheels it will affect not only the ignition timing but the valve timing.

If you really suspect this has happened put a timing wheel on the engine and check the valve timing. If the valve timing is changing as well, yes, then it might be time to split the cases.
"I know only too well the evil that I propose, but my inclinations get the better of me."
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Re: Timing moves

Postby Otis » Fri Jun 12, 2020 3:20 pm

I just set the timing again. When the narrow lobe just opens the points both front valves are closed and the same for the rear valves when the wide lobe opens the points leading me to believe the valves are in sync. Working on measuring the piston height next.
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Re: Timing moves

Postby themike » Mon Jun 15, 2020 10:49 pm

Mag drive gear is slipping = broken gear pin
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Re: Timing moves

Postby Ferrous_Head » Tue Jun 16, 2020 1:50 am

He's tried 3 different mags in there. I'm guessing it's not a drive pin problem.

Just having the valves closed isn't good enough.

But do the sanity check.

Check the piston height when you first set the timing. It should be about 11/16's BTDC. Whatever it is, write it down.

Kick the bike, start it, whatever you can do.

Check the piston height again. If it is different to what you wrote down then you can go further.
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Re: Timing moves

Postby Otis » Tue Jun 16, 2020 11:57 am

Seems like the pinion gear corrected the problem. I timed it statically and it’s holding. Originally I checked it after running and it did advance about 5-10 degrees but comes back dead on once cooled. Is it typical for it to change so much once at temperature? I believe my next step is to set it with a light when running and step away from it. Thanks for the suggestions.
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Re: Timing moves

Postby Ferrous_Head » Tue Jun 16, 2020 5:41 pm

I would be really surprised that a worn pinion gear could have put your timing out enough to measure a difference.

and no, timing doesn't change with temperature. If it did engines would be destroying themselves left right and center.
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Re: Timing moves

Postby No side stand » Thu Jun 18, 2020 3:40 am

Well done Otis.
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