Monster 696 Ignition Reference Point Question

[martin696CZ]

Hi Guys,

may be I have a special question... In the Workshop manual there is a description of the ignition. They wrote there that the sensor faces the timing gear and can "read" 44 teeth and 2 gaps of 2 teeth length positioned 180deg apart. My question is : WHAT ARE THE REFERENCE POINT RELATED TO? TO WHICH Cranshaft possition?

I am asking because I have to assemble new timing gear set for my Monster 696 and I do not see any marks there on the wheels. I do not know how to possition them one to another. The gears are already disassembled from the engine so I cannot mark their possition...

Thanks in advance a lot for all your replies!

Cheers

Martin

[krista]

The last time I saw timing gears, they and the gear on the crank each had a dot on the outside face of the teeth that point to each other.

[martin696CZ]

Thank you for your reply. But I wanna understand the engine... DOES ANYONE KNOW, what are the timing gear reference points related to what phase of the four stroke engine? I did a small research in this and I find out that one of the reference points is related to vertical cylinder intake valve closing point (60deg ATDC). But I am not sure. The next question is the purpose of the second reference point, because it does not fit to any interresting point on the four stroke L-twin...

I know it is some kind of quite special question but please help me if you have any idea...

Thanks in advance

Martin

[krista]

Oh, you're talking about the dots on the flywheel? I thought you literally meant the timing layshaft drive and driven gears, sorry. Normally, at least one of them is for each cylinder's TDC and/or "Fire". The dots on the timing sprockets refer to horizontal cylinder's TDC.

[brad black]

they're referenced to whatever point in the cycle the siemens engineers chose, so you'd have to ask someone at siemens.  probably points with fairly constant crank speed, altho it's odd they use two gaps 180 degrees apart, as that doesn't give cycle position with only one sensor.  maybe they pick up the position from the angular accel at different points in the cycle.

[caperix]

The sensor wheel on the older Marelli injection systems was a 46 - 2 tooth that ran at camshaft speed, half crank speed.  Adding the second reference point would give a crank speed reading.  Though I do not know how the computer could get a propper cam position reading off it for sequential injection if that was the reasoning. 

[brad black]

The sensor wheel on the older Marelli injection systems was a 46 - 2 tooth that ran at camshaft speed, half crank speed.  Adding the second reference point would give a crank speed reading.  Though I do not know how the computer could get a propper cam position reading off it for sequential injection if that was the reasoning. 

the 46 teeth gave the rotational speed, the missing two the position in the cycle.  that's why they could only run one sensor.

so if you have two cycle position references at identical intervals on the timing shaft you don't have cycle reference.