Notices
Carbureted LSX Forum Carburetors | Carbed Intakes | Carb Tuning Tips for LSX Enthusiasts

Don't know carbs. Need help.

 
Old 01-14-2019, 04:18 PM
  #1  
On The Tree
Thread Starter
 
discostu's Avatar
 
Join Date: Feb 2007
Posts: 123
Default Don't know carbs. Need help.

I know this is not a ls. However it's still cool. 69 with dz302 4053 holley. 72 primary 76 secondary. Vacuum reads 12. Power valve 6.5. Idle is 900 rpm. So problem is runs like crap. I can turn idle mixture screws all the way in and it doesn't affect motor at all. I've check float level. And used vacuum on the power valves to make sure they close they close at 5 psi I didn't see the psi drop while holding it there. Anything else I can do? Need help don't know what else to look for.
discostu is offline  
Old 01-15-2019, 09:16 AM
  #2  
In-Zane Moderator
iTrader: (25)
 
ZONES89RS's Avatar
 
Join Date: Jan 2007
Location: Conroe, Texas
Posts: 11,876
Default

You rebuild the carb yet?
ZONES89RS is offline  
Old 01-15-2019, 10:43 AM
  #3  
TECH Fanatic
iTrader: (1)
 
Kfxguy's Avatar
 
Join Date: Apr 2017
Posts: 1,551
Default

1) whats your vacuum at idle? the vacuum needs to be higher than the power valve
2) big cam? how much do you have the throttle blades cracked? are you past the tranfer port holes? i'd guess thats your issue

this may help if you havent read it.....

https://www.holley.com/blog/post/hol..._valve_tuning/
Kfxguy is offline  
Old 01-15-2019, 10:47 AM
  #4  
On The Tree
Thread Starter
 
discostu's Avatar
 
Join Date: Feb 2007
Posts: 123
Default

The vacuum at idle is 12.
stock 302 cam believe it was a 30-30
discostu is offline  
Old 01-15-2019, 07:17 PM
  #5  
TECH Junkie
iTrader: (1)
 
Pop N Wood's Avatar
 
Join Date: May 2006
Posts: 3,376
Default

Originally Posted by Kfxguy View Post
1) how much do you have the throttle blades cracked? are you past the tranfer port holes? i'd guess thats your issue
Turn the carb upside down and measure the transfer slot showing, both primary and secondary. Should be right at 20 thousands of an inch. Any more and you are off the idle circuits and the idle screw is ineffective. This link has a picture

https://www.onallcylinders.com/2013/...y-carburetors/

Blown power valve could cause it as well. As could a leaking gasket or blocked air bleed.
Pop N Wood is offline  
Old 01-16-2019, 08:42 PM
  #6  
10 Second Club
 
Doug G's Avatar
 
Join Date: Aug 2010
Location: Harford Co. Maryland
Posts: 3,894
Default

Agreed....too much transfer slot (butterfly too far open)
Doug G is offline  
Old 01-18-2019, 07:03 PM
  #7  
On The Tree
Thread Starter
 
discostu's Avatar
 
Join Date: Feb 2007
Posts: 123
Default

Thank you for the help. It was the secondary being open to far. After a few turn off the adjustment screw it works as it should.
discostu is offline  
Old 01-18-2019, 08:57 PM
  #8  
TECH Senior Member
 
Join Date: Jun 2016
Location: Central Cal.
Posts: 10,181
Default

Glad you got it fixed! And thanks for reporting back, as it will help others.
G Atsma is offline  

Thread Tools
Search this Thread

About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: