Author Topic: Setting timing with strobe.  (Read 1629 times)

Offline K2-K6

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Re: Setting timing with strobe.
« Reply #15 on: May 12, 2021, 10:41:52 PM »
I think the actual dwell on the Hondas is about 50% (180deg or 45 on a 4 cyl scale) Correct me if I'm far out.
What I am not clear on is that the dwell is set to give the inductive coil sufficient time to fully "charge" and also not over tax the coil.  But is it set so this is sufficient time at maximum rpm? (3.3ms at 9000 rpm) And therefore an overly long time at lower revs.
Also are electronic ignitions set so the give a fixed charge time at all rpms? So power drawn will be a lot less at idle say.

Crossed over with you there while typing  :)

They accommodate error with coil resistance on these systems, using 5 ohms to avoid overheating them at low rpm but sufficient to cope with charge rate at the higher end as I understand it.
As example, if you put 3 ohm coils on there they'd overheat at low rpm use (ignoring system switching requirements) but may be ultimately better at continuous high rpm when needing less time to fully charge them.

Offline fogrider

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Re: Setting timing with strobe.
« Reply #16 on: May 13, 2021, 12:52:17 PM »
Seabeaowner uses the correct terminology for dwell, %, not degrees, I've said degrees from the year dot, no idea why !

50% is the way to go for a points gap of .015."

I've had old Fords that have the points at .025", dwell for them around 40% I seem to remember.

A bit of discussion is good education, great forum this one.

Regards all, Terry
East Yorks.

Offline JezzaPeach

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Re: Setting timing with strobe.
« Reply #17 on: May 13, 2021, 01:17:15 PM »
Hi sorry to ask, having tried to visualise this....is dwell basically the fine adjustment within the range for the points gap? Given the opening point needs to be at the F mark, I can’t see any other adjustment.
1972 CB500/4 K1 Gold
Wanted: my 500/4 UGP96M
from 1975-78. Garnet Brown.

Offline K2-K6

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Re: Setting timing with strobe.
« Reply #18 on: May 13, 2021, 01:50:35 PM »
Hi sorry to ask, having tried to visualise this....is dwell basically the fine adjustment within the range for the points gap? Given the opening point needs to be at the F mark, I can’t see any other adjustment.

Yes, it's just the points gap facility that's changing to set it.

All things being equal and tolerancing of components being good, then all the numbers would line up. But with production of components having some variables then dwell setting tries to best mitigate the error wherever that may occur.

In essence,  it's favouring coil switch time setup over absolute points gap mechanical measurement.

Offline Bryanj

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Re: Setting timing with strobe.
« Reply #19 on: May 13, 2021, 04:49:28 PM »
With hondaman there should be zero pitting as current is minimal

Offline JezzaPeach

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Re: Setting timing with strobe.
« Reply #20 on: May 13, 2021, 07:25:34 PM »
Many thanks. As I think my cam spindle has a very minute bend in it I guess this could spoil the dwell on one side, so I’ll check it all when I use my replacement advance set next time I adjust the points. Very helpful.
1972 CB500/4 K1 Gold
Wanted: my 500/4 UGP96M
from 1975-78. Garnet Brown.

 

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