Carb Change / update and sight flow tube

C

clawless1

Cadet
Joined
Jul 1, 2013
Messages
15
Hi All,


So I read this thread and now realize what the yellow line is for:

http://forums.iboats.com/mercruiser...-5-0-stalls-when-coming-off-plane-559146.html

My question is - I am updating my carb and the new one does not have a provision for this line, at-least not in the same place. (I have an 82 330 TR w/a quadrajet) There is a brass tube coming out of the back of the secondaries where it could connect to, it looks to be an atmospheric vent though, circled in the pic. The original was on the front of the carb and connected into the float-bowl (it looks like). I believe the original one is a 4MV, the new one is a 4ME - is that OK?

I do not want to defeat the feature, is this tube the correct place to connect the sight flow line to?

Clawless
 

Attachments

  • Marine_QJet2.jpg
    Marine_QJet2.jpg
    26 KB · Views: 0
Howard Sterndrive

Howard Sterndrive

Rear Admiral
Joined
Nov 5, 2008
Messages
4,603
Re: Carb Change / update and sight flow tube

as long as that fitting on the new one dumps into the carb throat, it should be fine. It's just to keep the fuel from spilling into the bilge so they make the engine drink it in the event of a diaphragm failure. There are no atmosphere vents on those carbs. There are some vacuum fittings on automotive ones, but if that just dumps right into the large opening it should work.

I had a 330 TR years ago in a boat with a Merctrans II... neat setup. huge prop.
 
C

clawless1

Cadet
Joined
Jul 1, 2013
Messages
15
Re: Carb Change / update and sight flow tube

So I switched the carb out and put the site line at that fitting and all is well. I did find out that it had the open plenum gasket on it, not the 4-hole gasket. I put the 4 hole on it and the 4 barrel open noise is CONSIDERABLY quieter. It was to the point running on the 4 barrel that you had to yell to talk to anyone, now you can carry on a normal convo while cruising. Could that have been from the wrong gasket?

Yes, It is a massive setup - running a 19" diameter prop most people are shocked when they see it.
 
You must log in or register to reply here.
Top