Stroker Motor / Static Angle / Help Needed

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Off Road
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Re: Stroker Motor / Static Angle / Help Needed

#16 Post by Off Road » Mon Jun 11, 2018 2:50 am

I dug out my stock motor and found TDC, and then marked line “L”, (leading edge of the magnet covering the entire pickup),
and line “T”, (trailing edge of the magnet still covering the entire pickup).
The first thing I noticed was that the distance between TDC and the leading edge of the magnet was the width of 2 fingers, which is twice as far as on the stoker motor.

After a number of measurements, here’s what I found:

On the Stock motor, line L is 6.00 mm, or 35*, BTDC, and line T is 2.6 mm, or 23* BTDC.

Interesting to note that when the trailing edge of the magnet covering the pickup, line T is in the middle of the factory marks stamped into the rotor.
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Off Road
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Re: Stroker Motor / Static Angle / Help Needed

#17 Post by Off Road » Mon Jun 11, 2018 2:51 am

On the Stroker motor, line L is 14.75 mm, or 55* BTDC, and T is 8.8 mm, or 41* BTDC.

So, WTF?
Why is line L so far away from TDC, and why is the magnet on my rotor so close to TDC?
The rotor only goes on 1 way.
At first, I could only think of a couple of things that would be the problem.

1 – I’ve got the wrong rotor. I don’t know where I’d have got an incorrect rotor, but I’ll check it to confirm that it’s correct.
2 – The slot for the woodruff key, on the Stroker crank, is in the wrong spot. It is advanced from where it should be.



The next night I pulled the alternator cover off the stroker to have another look.
The stator is the correct 29L-50 stator.

I cleaned off some of the old lines on the stator, and remarked lines L and T.
Line T is in the middle of the factory marks on the stator, the same as it was on my stock engine.

Still, when you compare the 2 engines (stock & stroke) you can see that:
- TDC on the stroker motor is closer to the rotor magnet than TDC on the stock motor
- Line L is farther away from TDC on the stroker motor, than it is on the stock motor
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Off Road
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Re: Stroker Motor / Static Angle / Help Needed

#18 Post by Off Road » Mon Jun 11, 2018 2:51 am

Looking at the above picture it is clear that the rotor magnet is much closer to TDC on the stroker motor, than it is on the stock motor.

This means the stroker crank is rotating a larger number of degrees, after the magnet triggers the pickup (either line L or line T), until the piston is at TDC.



To get my ignition to fire at 17* BTDC, I had to program a Static Angle of 45*, and an Ignition Curve of 1*, into the Zeel.

My Zeel is delaying for 44*, before if fires the ignition, but it is still firing 16* earlier than the 1* BTDC that is programmed into the Zeel.

In order for me to program an ignition curve of 17* into the Zeel, and actually get the engine to fire at 17* BTDC, I would have to program a Static angle of 61*.


To me, it looks like the slot for the woodruff key, in the stroker crank, is in the wrong spot,

hondaror
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Re: Stroker Motor / Static Angle / Help Needed

#19 Post by hondaror » Mon Jun 11, 2018 3:29 am

The dwell of the piston on the stroker crank is longer, keep that in mind.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
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2005 749
2005 749 with 999 engine

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