Posted: Sun Sep 30, 2007 8:37 pm
Found this:
Setting the Throttle Potentiometer
This is an extract from a service bulletin issued by the factory in Oct 1992.
Model 907 & Cagiva Elefant 900 IE & GT models
remove the filterbox cover and the air filter; unscrew the anti-sticking screws i) and starter adjust ii). Screw up to the moment that the throttle is totally closed. Check this position by touching the filter side and having the throttle operated many times. (open the throttle a little and snap it closed ounce or twice)
Connect a digital voltmeter (accuracy=1mV) to the pin no 11 (-) and no 17 (+) of the central box terminal board iii) Then check that the voltage reading (switchboard On) to be 150 mV ± 15mV. Otherwise loosen the potentiometer iv) fastening screws setting their angular position up the the mentioned voltage figures are got. During this operation horizontal cylinder throttle must be forced to stay closed. (be careful what they say about being forced, what they actually mean is do not allow the turning of the potentiometer to open the throttle body butterflies)
Using the anti-sticking screw i) of the vertical cylinder (master) adjust the throttle opening up to a voltage reading of 300mV ± 15mV. In the same way adjust the anti-sticking screw of the horizontal cylinder up to the contact with its support, or when the voltage figure previously stated starts to increase. At this point the air flow rate of the throttle at idle rpm ratio is in condition to allow a positive and negative adjustment (rpm increase or decrease) using the by-pass screws.
Adjust the by-pass screws at one opening turn and after the usual preparation, arrange engine starting; under these conditions (20°C approximately for air, & oil temp.) rpm range must be stabilised at 900-1300 rpm approx. On the contrary, ( if this is inconsistent) check again with anti locking screws loosened, that throttles are resting on the duct indeed. (throttle body butterflies properly closed)
Go on with the usual procedure of adjustment (see our service bulletin No. 149 dated 20/06/90) specially paying attention to the mixture strength balance of the two cylinders (CO equal figure 3-6%) As a final practical test, alternatively disconnect the two ignition spark plugs, noting (using and auxiliary digital rev counter) that the engine rpm ratio decrease is repeated at the same figure.
Adjust the start opening screw ii) in a way to get an rpm rate of 3000± 500 n/1 with hot engine and starter totally turned on.
Notes for the above.
Anti-Sticking screws = throttle body butterfly stop screw
Starter Adjust screw = warm-up lever or choke
Central Box Terminal Board = ECU
potentiometer = in this case the throttle position potentiometer
The standard running configuration for these tests is to make sure that you have adequate ventilation for the exhaust. If you run the engine for extended periods you must have a cooling blower and the engine will have to be run using a remote fuel tank that holds just a small amount of fuel, remembering that the remote fuel tank must have a free flow return pipe as well as the normal fuel feed. The fuel injection system has a bypass that must be fed back to the tank. as an example I have a small lawnmower fuel tank with a fuel tap for feed and a return pipe welded into the top air space for the fuel return
Setting the Throttle Potentiometer
This is an extract from a service bulletin issued by the factory in Oct 1992.
Model 907 & Cagiva Elefant 900 IE & GT models
remove the filterbox cover and the air filter; unscrew the anti-sticking screws i) and starter adjust ii). Screw up to the moment that the throttle is totally closed. Check this position by touching the filter side and having the throttle operated many times. (open the throttle a little and snap it closed ounce or twice)
Connect a digital voltmeter (accuracy=1mV) to the pin no 11 (-) and no 17 (+) of the central box terminal board iii) Then check that the voltage reading (switchboard On) to be 150 mV ± 15mV. Otherwise loosen the potentiometer iv) fastening screws setting their angular position up the the mentioned voltage figures are got. During this operation horizontal cylinder throttle must be forced to stay closed. (be careful what they say about being forced, what they actually mean is do not allow the turning of the potentiometer to open the throttle body butterflies)
Using the anti-sticking screw i) of the vertical cylinder (master) adjust the throttle opening up to a voltage reading of 300mV ± 15mV. In the same way adjust the anti-sticking screw of the horizontal cylinder up to the contact with its support, or when the voltage figure previously stated starts to increase. At this point the air flow rate of the throttle at idle rpm ratio is in condition to allow a positive and negative adjustment (rpm increase or decrease) using the by-pass screws.
Adjust the by-pass screws at one opening turn and after the usual preparation, arrange engine starting; under these conditions (20°C approximately for air, & oil temp.) rpm range must be stabilised at 900-1300 rpm approx. On the contrary, ( if this is inconsistent) check again with anti locking screws loosened, that throttles are resting on the duct indeed. (throttle body butterflies properly closed)
Go on with the usual procedure of adjustment (see our service bulletin No. 149 dated 20/06/90) specially paying attention to the mixture strength balance of the two cylinders (CO equal figure 3-6%) As a final practical test, alternatively disconnect the two ignition spark plugs, noting (using and auxiliary digital rev counter) that the engine rpm ratio decrease is repeated at the same figure.
Adjust the start opening screw ii) in a way to get an rpm rate of 3000± 500 n/1 with hot engine and starter totally turned on.
Notes for the above.
Anti-Sticking screws = throttle body butterfly stop screw
Starter Adjust screw = warm-up lever or choke
Central Box Terminal Board = ECU
potentiometer = in this case the throttle position potentiometer
The standard running configuration for these tests is to make sure that you have adequate ventilation for the exhaust. If you run the engine for extended periods you must have a cooling blower and the engine will have to be run using a remote fuel tank that holds just a small amount of fuel, remembering that the remote fuel tank must have a free flow return pipe as well as the normal fuel feed. The fuel injection system has a bypass that must be fed back to the tank. as an example I have a small lawnmower fuel tank with a fuel tap for feed and a return pipe welded into the top air space for the fuel return