Go Back   TeamTalk > Maintenance Tips, How-tos and Refurbishing Topics > Engine / Drive Train

Reply
 
Thread Tools Display Modes
  #1  
Old 07-25-2013, 09:18 PM
jsun325's Avatar
jsun325 jsun325 is offline
TT Newbie
 
Join Date: Aug 2008
Boat: MasterCraft ProStar 190 1989 351
Location: Midwest
Posts: 14
Vacuum Gauge to Tune Carb

I've got a '89 ProStar 190 with a Holley 4160 carb. I know the carb can be tuned without a vacuum gauge but using one intrigues me. I've watched the video on the Holley website on using the gauge. They talk about hooking up the gauge to a full manifold vacuum port. The only vacuum port that I see on my engine is the one going to the PCV value. Is this the one I use? Is there another port that I am not seeing? Any insight is greatly appreciated.
Reply With Quote
  #2  
Old 07-25-2013, 09:54 PM
catamount catamount is offline
TT Enthusiast
 
Join Date: Feb 2012
Boat: 1987 ProStar 190
Location: Vermont
Posts: 351
This had me confused at first as well. Every automotive tuning video usually shows a port coming off of the throttle body, which none of us with marine carbs should have.

After careful inspection, I found mine... covered in several layers of paint it may be harder to notice. It is a hex head plug located on the back of the intake manifold here:



(this is not my picture, just something I found on the internet to approximate what you should see)
Reply With Quote
  #3  
Old 07-26-2013, 03:34 PM
jsun325's Avatar
jsun325 jsun325 is offline
TT Newbie
 
Join Date: Aug 2008
Boat: MasterCraft ProStar 190 1989 351
Location: Midwest
Posts: 14
Thanks!
Reply With Quote
  #4  
Old 07-26-2013, 03:58 PM
SugarLake's Avatar
SugarLake SugarLake is offline
TT Regular
 
Join Date: Sep 2009
Boat: 88 Prostar 190 351W 1:1
Location: Minnesota
Posts: 38
Is it OK to disconnect the PVC and use that one when setting idle mixture? I'm not sure if that matters at idle or not. The oil filler cap has a breather so crankcase pressure shouldn't be an issue right?
Reply With Quote
  #5  
Old 07-26-2013, 04:25 PM
j.mccreight@hotmail.com's Avatar
j.mccreight@hotmail.com j.mccreight@hotmail.com is offline
MC Maniac
 
Join Date: May 2010
Boat: 1989 MasterCraft TriStar 190 SE
Location: Houston, TX
Posts: 2,892
Yes it is totally okay to connect a vacuum gauge to the pcv port.
__________________
James

1989 MasterCraft TriStar 190 SE
Reply With Quote
  #6  
Old 07-26-2013, 04:36 PM
SugarLake's Avatar
SugarLake SugarLake is offline
TT Regular
 
Join Date: Sep 2009
Boat: 88 Prostar 190 351W 1:1
Location: Minnesota
Posts: 38
Quote:
Originally Posted by j.mccreight@hotmail.com View Post
Yes it is totally okay to connect a vacuum gauge to the pcv port.
Should I put a tee in the line or is it OK to just connect to the vacum port and leave the PVC line open?
Reply With Quote
  #7  
Old 07-26-2013, 04:46 PM
catamount catamount is offline
TT Enthusiast
 
Join Date: Feb 2012
Boat: 1987 ProStar 190
Location: Vermont
Posts: 351
Just curious, why aren't you guys using the dedicated manifold port?
Reply With Quote
  #8  
Old 07-26-2013, 05:00 PM
SugarLake's Avatar
SugarLake SugarLake is offline
TT Regular
 
Join Date: Sep 2009
Boat: 88 Prostar 190 351W 1:1
Location: Minnesota
Posts: 38
Quote:
Originally Posted by catamount View Post
Just curious, why aren't you guys using the dedicated manifold port?
Just convenience for me. Boats up at the cabin, want to do this tomorrow, and I don't know the thread size of the port to buy a nipple ahead of time. Saves me a 45 minute trip to the hardware store once I'm up there.

I'm assuming it's just a threaded plug in there now. Did yours already have a nipple installed?
Reply With Quote
  #9  
Old 07-26-2013, 06:11 PM
thatsmrmastercraft's Avatar
thatsmrmastercraft thatsmrmastercraft is online now
MC Master Poster
 
Join Date: Sep 2008
Boat: 1977 Stars & Stripes
Location: St. Paul, MN
Posts: 13,877
Anyone with an aftermarket intake manifold needs to Tee into the PCV line. Not a big deal.
__________________
Peter

Tandem Axle Trailer Special
Includes: 4 T07 wheels, 4 ST205/75R14 Kenda
Loadstar KR03 Radial tires, mount and balance
Free Delivery


ALUMINUM WHEEL AND TIRE PACKAGES
SINGLE AXLE 14" PACKAGE STARTING AT $369
SINGLE AXLE 15" PACKAGE STARTING AT $439
TANDEM AXLE 14" PACKAGE STARTING AT $649
LED lights, Spare Tire Carriers, Chrome & Powder Coated Lug Nuts
GOLF CART TIRES & WHEELS

PM me or email tiresplease@gmail.com
Reply With Quote
  #10  
Old 07-26-2013, 07:21 PM
j.mccreight@hotmail.com's Avatar
j.mccreight@hotmail.com j.mccreight@hotmail.com is offline
MC Maniac
 
Join Date: May 2010
Boat: 1989 MasterCraft TriStar 190 SE
Location: Houston, TX
Posts: 2,892
Quote:
Originally Posted by SugarLake View Post
Should I put a tee in the line or is it OK to just connect to the vacum port and leave the PVC line open?
No need for a tee, just leave the hose off the pcv valve and install vacuum gauge hose into pcv hose.
__________________
James

1989 MasterCraft TriStar 190 SE
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -4. The time now is 06:33 PM.