scavenge tube

[Jim c]

Hi i am new to this forum and new to Atom 4 , a few month ago i pick up a 78 27 foot newport that been siting in the water for over 13 years the A4 had four frozen piston plus ,so anyway instead of trying to rebuild i found a complete rebuilt older model A4 that i switch out with out too much problem but when i started to hook every thing up i ran into this problem on the manifold no place to hook up the scavenge tube ? any ideals i know that the scavenge tube is a uscg requirement plus i hate leaking gas and i really hate blowing up i did find something from Indigo but any help would be great thank you Jim

[Al Schober]

Seems you have two choices.
First is to drill and tap that manifold (1/8" NPT) for the scavenge tube. If you have a drill press you should be able to do it yourself. Or a machine shop could do it.
Second is to change out the manifold for one that already has the port for the scavenge tube. Do you still have the takeout engine?
For either choice, evaluate the condition of the manifold. They have a finite life, and a new manifold may make sense in the long run.

[Tim]

Moyer sells a flange adapter for manifolds that don't have the port already drilled and tapped. https://moyermarine.com/product/carb...fcar_13-2_166/

[Al Schober]

Three choices. Thanks Tim!

[Jim c]

First of all I want to apologize for taking so long to get back , second of all thank you for all the responses . So I decided to go with the indigo crankcase ventilation system they also have flange adapter ,and it seems like a smart way to go for just a few more dollars to avoid smoke in my small boat I'll let you know how that works out. thanks again for all the help I'm sure I'm going to need some more. jim c

[Tim]

The flange on the Indigo pcv kit has a port to connect a pcv valve. That will still leave you with no place to connect the scavenger tube.

[Tim]

Update: The Indigo flange for the PCV has a second port for adding a scavenger tube, you will be good with the Indigo system.

[Marian Claire]

It is my understanding that the early carbs have an internal scavenge system. Therefor no need for an external scavenge tube or port in the early manifolds. Seems you have a late model carb and a early model manifold.

Dan
S/V Marian Claire