Coil Swap

MightyBoy tech questions and answers.
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Brayden
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Joined: Sun Apr 11, 2004 3:09 am
Location: Canberra ACT
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Also check voltage at the battery. If the fusible link (or some other connection) has partially failed the engine won't idle properly.
F8B EFI turbo - Three pots and a snail.
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Breyten
Posts: 364
Joined: Thu Jan 28, 2010 10:06 pm
Location: Perth - North

The points in the dizzy? Please explain? I'm still learning which bits do what.
1987 Suzuki Mighty Boy - F5A, stocker.
Work fleet, or Wife's Jeep Rubicon.
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rf4burns
Posts: 162
Joined: Fri Sep 03, 2010 7:26 pm
Location: Central QLD

this maybe of some help with identification
ign basic
ign basic
No fuses etc shown -not sure if the manual shows how to set points but try looking there if it is not clear and you require a pictorial ask and I will endeavor to provide one.
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Breyten
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Joined: Thu Jan 28, 2010 10:06 pm
Location: Perth - North

Yep, but looking in, how to I set/gap the points in the dizzy? Thing springs shut with some decent pressure. Have new ones here to put in to try.

Brayden, do you have any specs available for the fusible link? Or a suggested, more conventional, replacement?
1987 Suzuki Mighty Boy - F5A, stocker.
Work fleet, or Wife's Jeep Rubicon.
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Breyten
Posts: 364
Joined: Thu Jan 28, 2010 10:06 pm
Location: Perth - North

Wait, figured it out. Just need to turn it a bit. and get something to measure it with.
1987 Suzuki Mighty Boy - F5A, stocker.
Work fleet, or Wife's Jeep Rubicon.
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Billie
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Joined: Mon Aug 17, 2009 9:18 pm
Location: Brisbane

Fieler gauge.
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Tez
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Joined: Wed Sep 03, 2008 9:38 pm
Location: Croydon, Vic

Using feeler guages (the only reliable way to do it) - set the Gap in the points on any one of the three lobes on the rotor shaft to 0.45mm (for both F5A & F8B engines).

So, with the plugs out of the engine (to reduce compression) - Rotate the engine (I yank on the fan belt) until a lobe is right on the points wiper, then remove the old points and fit the new points. You'll see the gap can be adjusted by locking one of the screws anywhere in a slot.

Tighten the OTHER screw up until NEARLY tight, then set your feeler guages to give you 0.45mm and open the points and put the tip of the feeler guage between the points faces and allow the spring of the points to close them onto the feeler guage.

Now tighten up the second screw (the one over the slot) and then tighten up the first pivot screw fully. - You don't need to be a gorilla - they just need to be firm.

Gently pull the feeler guages from between the points faces and the gap should remain - The feeler guage should just slide through the gap - you'll feel the points faces rubbing on each side of the feelers... Hard to describe, but you'll know it when you feel it!

Now rotate the engine until the next lobe opens the points and check the gap is correct using the feeler gauge. - Good? - Good! - No? - Loosen the two screws and reset.

If the gap is good, put the plugs back in - since you've got them out, Check the gap between the electrodes on them is between 0.7 & 0.8mm as you fit them and adjust those if necessary, then put the rotor back on the dizzy shaft, and the cap, recheck the HT leads are feeding the plugs in the correct order, and try starting the car...

Least, that's how I do it...

Good luck!
Tez
So the adventure continues...
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Psi_Wagon
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Joined: Sun Jul 20, 2008 11:04 pm
Location: Melbourne, North-West
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to make it easier, you dont need to take the plugs out. you can take out the bolt that holds the dizzy and turn the dizzy rather than the the engine. but u may have to recheck timing, unless you mark where it was beforehand.

on a side note, im amazed at how much timing im able to run on my f8b with the mods ive done. stock is supposed to be around 7 degrees, but im running upwards of 20 with no signs of pinging at all!
http://www.calaisturbo.com.au/showthread.php?t=180305
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Brayden
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The F8B's low compression probably has a lot to do with that, although 20deg advance sounds implausibly high!
F8B EFI turbo - Three pots and a snail.
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Psi_Wagon
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Location: Melbourne, North-West
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thats the thing, its not standard comression, its at around 9.5-8/1
20degrees initial timing, total would be around 30. plenty of torque :)
http://www.calaisturbo.com.au/showthread.php?t=180305
ssc87
Posts: 97
Joined: Wed Aug 12, 2009 11:34 pm
Location: Newy

Being a coil swap thread of decent info i put up my particular 3 pin coil has th an extra brown/white wire on the -ve aswell as the points lead,? +ve now has the two leads running from both other positive posts and the suppressor. Gt40r coil upgrade so i joined them as per further back, but where is the original ballast resister .have another supplied with the coil it is a 1.6ohm, should i replace or leave it?

Edit: Looking through the wiring diagram brown wire is supposed to go to points but i had a seperate black wire running across, so thats solved.
ssc87
Posts: 97
Joined: Wed Aug 12, 2009 11:34 pm
Location: Newy

After reading another thread the 3 post coil has an internal resistor to bring it up to 3 ohms resistance total compared to a 1.5 coil and 1.6 external. So if irun a 12v coil with 3ohm internal resistance it should be fine and theoretically pulling the same current? Gt40t if i can find 1.

Edit su12 coil is a new bosch transformer coil 3 ohm internal resistance $40 supercheap full 12v
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