'70 40hp Vacuum lines

[dmgroh]

Restoring 1970 Johnson 40 hp electric shift. It has 3 vacuum nipples; one on starboard side, just under magneto; second on front of intake, 2" below throttle plate, and third on lowest starboard side of intake. <br /><br />Can anyone enlighten me what the connections are? Perhaps all the parts were not in the 2 buckets of disassembled items I received?

 

[Paul Moir]

Re: '70 40hp Vacuum lines

The one on the starboard just under the magneto, and the one way down near the bottom of the block are part of the oil recirculation system. There should be a hose that goes between the two. This pumps oil that pools in the bottom of the bottom crankcase chamber up to the top crank bearing.<br /><br />The nipple on the intake manifold should connect to the vaccum cutout switch. The purpose of this setup is to temporarily cut ignition on one cylinder when the throttle is snapped closed. If it isn't present, the engine can run-away, where it turns up to incredible rpms all by itself. I belive it also works at high rpm / high vaccum conditions, like when you snap a shear pin or rev the engine in neutral.<br /><br />Hope that explains it!

 

[lark2004]

Re: '70 40hp Vacuum lines

only two buckets eh? mine was spread across a whole trailer.... I s'pose there were two engines in mine though.... Yeah what Paul said, And anything else to do with these engines, listen to what paul tells you.

 

[dmgroh]

Re: '70 40hp Vacuum lines

Thanks! It is only 2 buckets because I probably didn't get all the parts..

 

[lark2004]

Re: '70 40hp Vacuum lines

lol, the good part is that there are lots of these motors around, parts are real easy to find.<br />Most outboard wreckers have several.