Oil Line?

[bwkre]

76 Evinrude 25hp.
Small hose from upper bypass cover to front of intake manifold.
Anyone describe the purpose of this line?
Thanks,

 

[backwater52]

collects oil and lubes lower main bearing i think

 

[racerone]

How does it lubricate the lower main bearing when this hose goes to the upper bypass cover for cylinder #1 ??----Or was that a wild guess ?

 

[Crosbyman]

racerone... no PM's on your profile ?

 

[racerone]

Correct ---no need for messages.

 

[Crosbyman]

Correct ---no need for messages.

How to Use Proper Forum Etiquette | Boating Forum - iboats Boating Forums

3 & 6 are pretty good

 

[bwkre]

Well I think the outlet from the bypass cover provides pulses same as used to operate the fuel pump on the other cover. But this outlet has a very tiny oriface fitting and the line goes into the lower section of the intake manifold. Just curious as to it's purpose.

 

[Crosbyman]

the intake manifold shows a drain valve behind the nipple so it may very be a means of literally sucking out any accumulated unburnt fuel/oil deposit which can accumulate when running at low rpms this is sometimes dumped overboard in older models using a one way valve to push out the residues on the piston down stroke
this oil line brings the residues back into the piston for burning rather than dumping it in the water unburnt

 

[Crosbyman]

see description on older models...

 

[bwkre]

Thank you,
I appreciate your taking the time and effort to provide an explanation.
Above and beyond.
Learned something new today.