Dave Ett wrote:Oh right, I assumed they were a standard piece of kit. Good bit of gen there, but I have no idea where you'd get an NSR specific one from. Are our engines that different they wouldn't work then?

You'd need to run the long shortie sparkplug (R7282-105A) as the detector goes underneth the plug and probably get the head machined to allow the detector itself to clear the cast part of the head (look at an NSR head, the plug sits "in" it quite deep, probably more than a washer or two), a std plug is too short anyway and it's "nut" is too big to clear the detector at all. Kev Moose posted about these ages ago on twostrokes.com, he was selling the same ones, he reckoned there was not reason one wouldn't work on an NSR as "all" it does is listen for the right noise.

This is what he told me about them;

Detonation detection system

This system is optimised for RS125 / RS250 / TZ250 Engines

Overview
Detonation is the pre-ignition of fuel in the cylinder and can cause piston damage; a certain level of detonation is good (fuel dependant) to ensure that the engine is running at the optimal level. The detection system allows detonation to be detected and a bright indicator flash indicates a detonation has occurred to warn the rider. The number of detonations can be counted if the counter option is fitted.

The April systems detonation detection system allows a plug together system that can be simply expanded from a simple single cylinder system to a full dual cylinder system and to other data recording/logging systems.


System variations:

Single Cylinder Option A : Simple detonation detection @ £130.00
1 detonation detector
1 power lead and blue indicator flash


Single Cylinder Option B : Detonation detection and counter @ £280.00
1 detonation detector
1 power lead and blue indicator flash
1 detonation counter

Twin Cylinder Option A : Simple detonation detection @ £260.00
2 off detonation detector
2 off power lead and blue indicator flash

Twin Cylinder Option B : Detonation detection and counter @ £380.00
2 off detonation detector
1 off power lead and blue indicator flash
1 off detonation counter


All the above options are built from the basic components of:
. Detonation detector
. Power lead
. Counter unit

The power lead can be either blue indicator or a connector to a data logger.

Detector unit


The detector system compromises of: a detector sensor plate and a small amplifier unit. The detector sensor plate detects the physical head deformation and passes this signal to the amplifier. The amplifier produces two output signals:
a) An indicator drive for the blue indicator
b) A standard detonation profiled pulse

The (b) output can be coupled to other type of detonation detection systems such as
Honda detonation counter and logger
BPS CDi ignition and engine control systems
Cougar Data Recording motorcycle logging system
If connection to one of the above is required then request a power cable with a logger output connection. Note that the BPS/cougar cylinder pressure cannot be measure by this type of sensor

On powering up the unit will generate a detonation signal and/or flash the indicator this is normal.




Counter unit


The counter unit (for single or dual cylinder) has two detonation detector inputs labelled (1) and (2) and a power connection. The detector amplifier/s are then powered via the counter unit.

. The count values are stored in a non-volatile memory and so are unaffected by having the power removed.
. The value normally displayed is the addition of cylinder 1 and cylinder 2 count values
. Pressing the button briefly once will cycle through the count values
The display will show ….

1=
{Cylinder 1 count value}
2=
{Cylinder 2 count value}
Total
{Addition of cylinder 1 and 2} the normal display

. When cycling through the cylinder counts the counter system will continue to count any detonations
. 20 seconds after a button is pressed the display will fade to reduce power consumption
. To reset the values: press and hold the button for 2 seconds
. The inputs to the unit are compatible with standard detonation sensors
. The counter unit does not have a compatible output for loggers this signal would be taken from the detector unit/s.

Installation Procedure

The detonation detector requires the use of an extended length spark plug. The assembly order is to place the detector plate on the head and then the copper washer (or two as required) screw in the spark plug and tighten to 24 N.m or 18 lbf.ft

The tightness of the plug is critical on the detection process, too tight and the sensor will be over sensitive.

If the head is recessed then fit the copper washer/s first then the detector plate.

WARNING fit copper washers only on one side of the plate not on both, as this will inhibit the operation of the detector

Check that the head volume is now correct. Tape all unused connectors to stop water ingress.

WARNING: The detector amplifier unit must be mounted at least 80mm away from the ignition coils. Also route all detector cables away from HT leads or the coil.

Honda Power connections
Wire behind the tachometer:
Red positive power to Honda black
Green Chassis to Honda green

Yamaha Power connections
Wire behind the tachometer:
Red positive power to Yamaha Brown
Green Chassis to Yamaha Black


. Mount the blue indicator in the dash foam pointing towards the rider.
. Velcro mount the detector amplifier unit to the inside of the chassis.
. DO NOT MOUNT ON THE SIDE OF THE COIL
. Ensure all cables are away from the HT leads.
. Velcro mount the counter unit in a visible position and ensure that the button cannot be pressed accidentally or pushed by other cables.



Specifications:

Detector
Voltage range 9V to 20V
Input Current 5mA nominal 20mA peak
Detector plate temperature range -10degC to +130degC
Amplifier temperature range -10degC to +60degC
Weight Approx 50g
Detonation output -40V 1mA 16uS
Led output +5V 5mA 200mS

Counter
Voltage range 9V to 20V
Input Current 50mA nominal 150mA peak
Temperature range -10degC to +60degC
Weight Approx 60g
Inputs 2 off –40V 16uS piezo
Led output +5V 5mA 200mS
Max count 99999


 
_________________
Please do not PM me technical questions, if you can't find it on the Forum start a thread