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zul8tr
03-22-2010, 03:44 AM
On the Yamato Y80 and 102 (and maybe on the 202?) the factory manual states that the point setting is 0.012" to 0.016". I understand how to synchro the mag and points to the desired piston depth BTDC with buzzer box and dial indicator, but what is the point setting to use to get started? Does it matter as long as it is in the gap range noted in manual?

In aircraft energy transfer mags are used and point gap does matter with regard to what they call E gap (effeciency gap) to achieve the points opening at the magnetic neutral position to get the highest intensity spark (they call it mag synchronizing) in addition to timing the mag to the correct piston position BTDC. I assume that the mags used in the Yamato are not of this type so maybe point gap is not that critical as long as it in the design range of the mag?

Comments appreciated:)

Thanks

bill boyes
03-22-2010, 07:45 AM
I set the 102 at .014 on number 1. time the motor at 235 or so and lock the mag down. Will need several tries as the timing will move some while locking it down. Then set number 2 points at .014 and you will be there.
This advice is from TJ several years ago and has worked for me.

mercguy
03-22-2010, 08:07 AM
On the Yamato Y80 and 102 (and maybe on the 202?) the factory manual states that the point setting is 0.012" to 0.016". I understand how to synchro the mag and points to the desired piston depth BTDC with buzzer box and dial indicator, but what is the point setting to use to get started? Does it matter as long as it is in the gap range noted in manual?

In aircraft energy transfer mags are used and point gap does matter with regard to what they call E gap (effeciency gap) to achieve the points opening at the magnetic neutral position to get the highest intensity spark (they call it mag synchronizing) in addition to timing the mag to the correct piston position BTDC. I assume that the mags used in the Yamato are not of this type so maybe point gap is not that critical as long as it in the design range of the mag?

Comments appreciated:)

Thanks



set #1 at .014, then use your buzz box to set the timing (I set mine at .240) and lock the mag down, then set the timing (when the points open)for the bottom set of points at (again mine were at .240), don't worry about the gap on the bottom set, as they will be pretty close to the same as the top set, due to the points cam profile. The main point (no pun intended) is to have them firing 180 apart, as you are aware of......

I never noticed any difference in timing at .220-.250.............

this is where the 302 is MUCH better............no points or timing changes to worry about all the time, just lock the mag down and go racing..........

zul8tr
03-22-2010, 10:34 AM
Looks like the average point setting of 0.014" is used between 0.012 and 0.016".

The Y80 manual says set timing between 0.180" to 0.200" and 0.220" has been suggested for 7100 rpm operation. Any thoughts on that?

The 102 manual has the timing at 0.20 to 0.25" much higher than the Y80.

Thanks for the info.