7th Gear Designs

Detonation on deceleration?  Are you sure?  I've never heard of such a thing.

Nessism wrote:

Detonation on deceleration?  Are you sure?  I've never heard of such a thing.
 

I believe Feanor is from Spain and not a native speaker of English. I think he meant that there is backfiring on deceleration, which would be an easy mistake to make.

That could be a lean condition or an exhaust leak.

Wookie58 wrote:

You can check the ignition advance with an "adjustable" timing light. Set the engine speed at the required revs then dial in the timing light until the TDC mark is aligned. You can then read the advance data from the display on the timing light
PS: have you grounded the brown and blue wires as per the fitting instructions ?

This ignition has a triple spark system which according to the seller is not compatible with the timing light, As explained here:  7thgeardesigns.com/FAQ_Downloads.html

Have you successfully used an ignition light? I have one, but it is not adjustable

Nerdy wrote:

Nessism wrote:

Detonation on deceleration?  Are you sure?  I've never heard of such a thing.

 

I believe Feanor is from Spain and not a native speaker of English. I think he meant that there is backfiring on deceleration, which would be an easy mistake to make.

Thanks, that's what I meant. But apparently it's been fixed now.

Feanor_twh wrote:

Wookie58 wrote:

You can check the ignition advance with an "adjustable" timing light. Set the engine speed at the required revs then dial in the timing light until the TDC mark is aligned. You can then read the advance data from the display on the timing light
PS: have you grounded the brown and blue wires as per the fitting instructions ?

This ignition has a triple spark system which according to the seller is not compatible with the timing light, As explained here:  7thgeardesigns.com/FAQ_Downloads.html

Have you successfully used an ignition light? I have one, but it is not adjustable

You didn't mention the brown and blue wires - from what I read not grounding these will give you the symptoms you described (not revving past 5500) looking at the link you posted a timing light isn't going to work correctly with this set-up so you can only assume the advance is correct !!

Wookie58 wrote:

Feanor_twh wrote:

Wookie58 wrote:

You can check the ignition advance with an "adjustable" timing light. Set the engine speed at the required revs then dial in the timing light until the TDC mark is aligned. You can then read the advance data from the display on the timing light
PS: have you grounded the brown and blue wires as per the fitting instructions ?

This ignition has a triple spark system which according to the seller is not compatible with the timing light, As explained here:  7thgeardesigns.com/FAQ_Downloads.html

Have you successfully used an ignition light? I have one, but it is not adjustable

You didn't mention the brown and blue wires - from what I read not grounding these will give you the symptoms you described (not revving past 5500) looking at the link you posted a timing light isn't going to work correctly with this set-up so you can only assume the advance is correct !!

Yes, brown and blue wires grounded.

As someone already suggested, it could be that the TDC mark on the crankcase does not match the real TDC, I didn't check this. However, with the points there was no ignition problem, which makes me assume that it is fine.
It seems that the ignition map is incorrect. I can't think of anything else. I'm waiting for a response from 7thgeardesigns (he probably won't answer) and I also wrote to Power Arc. I'll post about what I find out.

The factory TDC mark my well be "a few degree's off" (manufacturing tolerances) but it wouldn't be enough to give you this problem, certainly sounds like a mapping issue (unfortunately due to the nature of the system you have no way that I am aware of to actually check the advance)

It is possible that the incorrect timing curve is loaded on your ignition. Total advance should be happening at 3000RPM. Here is the ignition curve that Powerarc created for the KZ twins, taken from their software. You can connect the ignition to a windows based computer to access the timing maps and use the Powerarc software. Its also possible to connect the extra wire to trigger a second map.

what spark plugs are you running? Power arc requires the use of resistor spark plugs. Could be a fuel mixture issue as demonstrated by increased popping on decel.

 

Are you sure you have a "good" ground on the brown and blue - you can check his with a voltmeter with the engine running (meter on DCV black meter lead to battery negative terminal - red meter lead to your ground connection, any more than 0.3v signifies a bad ground which triggers a softer advance map)

I would suggest that you go back through the install and check all grounds and power supply's with a voltmeter, as Doc says ensure you are using "resistor" plugs.
You might want to try installing "exactly" as per the instructions without your mod to include the original baseplate - hopefully the unit isn't faulty as reading the "warranty terms" you have no warranty due to your modification of the base plate (cutting a hole in it) !!!!!      

DoctoRot wrote:

It is possible that the incorrect timing curve is loaded on your ignition. Total advance should be happening at 3000RPM. Here is the ignition curve that Powerarc created for the KZ twins, taken from their software. You can connect the ignition to a windows based computer to access the timing maps and use the Powerarc software. Its also possible to connect the extra wire to trigger a second map.

what spark plugs are you running? Power arc requires the use of resistor spark plugs. Could be a fuel mixture issue as demonstrated by increased popping on decel.

 

I did tests with the ignition gun, which although not suitable for this type of ignition, gave conclusive results:

The ignition advances progressively from the F mark to the two-line mark of the total advance through the first 3,000 rpm.
After that, it remains steady until about 5,700 rpm, when it begins to oscillate between the two lines and the F mark.
Finally (6,000 rpm onwards) the ignition moves back to a point between the F and T marks (closer to T) and continues in that position for the rest of the rpm range.

All tests gave the same results. I deduce from this that the device is not broken, it sounds more like an incorrect ignition mapping.

What do you think?