Help Me ID This Nipple on Intake Manifold- Missing Part? '99 Evinrude 70HP 4 Stroke

[kahuner]

I noticed a squealing noise that I originally thought was a bad belt tensioner bearing.

Instead; it's an (open to atomosphere) brass nipple, that is on the front of the intake manifold, pointing to starboard directly at the silencer and throttle body. The nipple would take a 3/8" hose.

I can't believe this is supposed to be open. It's drawing air directly into the intake manifold, creating a squeaking sound that can be heard thru the engine cover at idle. If I close the nipple w/ my finger, the motor will die.

Neither BRP's or Seloc's online manual illustrates this port nor describes it's function or purpose.

Can anybody tell me what this is and whether or not there is a missing hose/ part?

 

[DargelJohn]

Re: Help Me ID This Nipple on Intake Manifold- Missing Part? '99 Evinrude 70HP 4 Stro

First thing I would do is get a flashlight and look around in the pan for a loose hose that may have been attached to the nipple. Don't know much about 4 stroke outboards, but may be a crankcase vent recirc hose connection.

Check out this diagram. http://www.boats.net/parts/search/BRP/EVINRUDE/1999/E70PL4EEC/INTAKE MANIFOLD/parts.html

 

[kahuner]

Re: Help Me ID This Nipple on Intake Manifold- Missing Part? '99 Evinrude 70HP 4 Stro

John;

Yes the probablity of the nipple being a recirc hose was my first thought after thinking about it. However......

The diagram in your link is the same exploded view used in the BRP and Seloc service/ parts manuals. Because both manuals use exploded views that are viewed is from the portside, the nipple is hidden and I can't make "heads or tails" from the diagram.

It'd be nice to know "to which" component the hose would be connected from the intake manifold.

Thank you for your suggestion.

Kahuner

 

[AlTn]

Re: Help Me ID This Nipple on Intake Manifold- Missing Part? '99 Evinrude 70HP 4 Stro

have you tried posting this question on the suzuki forum?

 

[bsmithbum]

Re: Help Me ID This Nipple on Intake Manifold- Missing Part? '99 Evinrude 70HP 4 Stro

Any chance you could snap a pic of the area and part you are explaining and attach it here? Might be able to better help that way. It almost sounds to me that what you are talking about should be a hose going from the intake to the silencer?

 

[kahuner]

Re: Help Me ID This Nipple on Intake Manifold- Missing Part? '99 Evinrude 70HP 4 Stro

No, thinking that there would be more activity on this forum.

Here's an update.

I've traced a black rubber hose from the elbow on the manifold (which is just above the straight brass nipple that I'm asking about) that leads to a silencer. The other hose attached to the silencer was routed rearward and OPEN.

Should that open hose (from the silencer) also be connected to the brass nipple? Or; is there a second hose that should run from the brass nipple rearward, and left open, to muffle the sound of air entering the manifold?

Something so simple, yet it's drivin' me nuts!!

 

[clanton]

Re: Help Me ID This Nipple on Intake Manifold- Missing Part? '99 Evinrude 70HP 4 Stro

Hose number 24 goes to the manifold nipple. I will check OEM manual later today.

 

[kahuner]

Re: Help Me ID This Nipple on Intake Manifold- Missing Part? '99 Evinrude 70HP 4 Stro

Clanton;

Correct but there's 2 nipples on the manifold.

On my engine hose #24 is present and connects to the silencer (#12). The other hose on the silencer runs rearward and is open to atmosphere.

The brass nipple I'm questioning, is just below the nipple to which hose number 24 connects.

I hope you can help me!

Thanks;
Kahuner

 

[daselbee]

Re: Help Me ID This Nipple on Intake Manifold- Missing Part? '99 Evinrude 70HP 4 Stro

That is the air intake for the idle system. That's why it kills the engine when you block it. It remains open.
There is another nipple on the intake with a hose that goes to the IAC Silencer (plastic cylinder with two hoses near the incoming fuel filter), and the other hose off the IAC Silencer snakes it's way up and over the intake manifold down behind the VST and just lays there...OPEN to the atmosphere.

Really.

EDIT: It is driving you nuts because you are chasing a non-existent problem!

 

[kahuner]

Re: Help Me ID This Nipple on Intake Manifold- Missing Part? '99 Evinrude 70HP 4 Stro

Got it! It's no longer driving me nuts because now I know it's supposed to be open.

Thanks for the reply; seriously!

Kahuner