Distributor Lines

[Knottofs]

[FONT=&quot]What are the "Air lines / Vent lines" that go to one side and out the other side of the Distributor for? When I bought the truck most were closed off with bolts stuck in them. Where can I find a diagram of the venting system? Thanks, Nate[/FONT]

 

[Warthog]

The truck is setup for water fording if needed. The distributor is sealed The lines are there to allow air inside the distributor so there is oxygen for the spark.

There are some tech manuals available. The owner of www.m715zone.com scanned them and has them available at that site. There are some paper versions out there but are getting hard to find.

I used the manuals to replace all the missing vent and fuel lines on my first MV which was a M715.

 

[1958 M274]

I'm not sure how the lines are plumbed on a 715, but I know on some other MVs one distributor vent line will be hooked to intake manifold vacuum and the other to the clean side of the air intake between the air cleaner and carburetor. My theory on this has been that the little air flow helps keep the coil and other ignition components from getting as hot inside the sealed distributor.

 

[dmetalmiki]

They are "vent" line to allow for condensation pressure ventilation inside the distributor casing. Is why they go from the Air filter inlet clean side Casing to the air filter return. (intake) does not (and is not for) the "contac breaker" Spark which is controlled (limitted as far as possible to avoid burning the contact points when they open and close) by the condenser in the contact points assembly.

 

[NDT]

If the lines are not hooked up and ventilating, the points will burn up in short order.