Cris,
Its is the actual rpm, detectable by sound, Tach, and seat-of-the-pants
feel.
Tonight I'll check the throttle shaft bushing and the damper oil.
Thanks for the suggestions,
Regards,
Glen Byrns
'59 bugeye
> Glen -
>
> Generally electronic ignitions are a go-nogo it either works great, or
> it doesn't work at all. The coil can be flaky at certain RPMs, so that
> might be worth checking.
>
> Is there an audible change in the engine speed, or are you going purely
> by the indicated speed on the tach? You called it a flutter, so I guess
> my question is, is the engine dropping RPM for a few seconds then coming
> back up, or is the tach needle flicking down, with an accompanying
> stumble?
>
> The former sounds like mixture, so it could be the damper oil in the
> carbs, worn shafte, or float level.
>
> If it's the latter, it's possible that the problem is in the tach or the
> accompanying wiring. If the tach lead from the coil grounds out for a
> moment (either inside the tach or in the lead) the needle could flutter,
> causing a misfire. Maybe at 3000 rpm the lead is vibrating just right
> to have a make-break in the wire?
>
> Glen Byrns wrote:
> >
> > I had posted about the 'flutter' of about 500 rpm either side of 3000
rpm
> > when attempting to hold a steady throttle setting at 3K. One suggestion
was
> > wear in the dizzy shaft.
> > Last night I rebuilt it with the housing and shaft of a 25D dizzy that
had
> > NO play in the shaft. It runs great and has no wobble at all, but the
rpm
> > still varies at 3K.
> >
> > Ideas? Throttle shaft bushing? Gremlins? Flaky chip in the Elec.
Ign.?
> > Will the solution involve the sacrafice of a neighbor's cat or two?
(wishful
> > thinking)
>
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