1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Extreme carburetor flooding. Help please!

Thread Tools
 
Search this Thread
 
Old 05-11-11, 01:27 PM
  #1  
Full Member

Thread Starter
 
Zero5360's Avatar
 
Join Date: Mar 2005
Location: USA
Posts: 95
Likes: 0
Received 0 Likes on 0 Posts
Extreme carburetor flooding. Help please!

I have a '79 and the carburetor is flooding BAD. When I turn the key on, the fuel pump kicks on and fuel begins to build up in the carburetor to the point it actually floods out the top. I have cleaned up motorcycle carbs, so I figured that I would take this one apart and see if the needle was sticking. I appears to be working fine. Is there something that may be dirty that sends the fuel from the bowl to the barrels? I read the flooding answers on the FAQ page with no success. Help please!
Old 05-11-11, 01:44 PM
  #2  
Stu-Tron Get Yo Groove On

iTrader: (4)
 
Jeezus's Avatar
 
Join Date: Nov 2006
Location: Huntsville AL
Posts: 8,405
Received 9 Likes on 9 Posts
Have you beat the top of the carb with a screwdriver handle? That usually unsettles sticky needles.

You can also take the top off and push it with your finger to check the springieness, for lack of better words.
Old 05-11-11, 01:50 PM
  #3  
1st-Class Engine Janitor

iTrader: (15)
 
DivinDriver's Avatar
 
Join Date: Jun 2008
Location: Chino Hills, CA
Posts: 8,376
Received 26 Likes on 24 Posts
The two float needles are the only places fuel is supposed to get into the carb from. Stuck needles are by far the most common cause.

If the carb was rebuilt improperly, it can also leak in from around the needle seats if they were left too loose, or if the crush washers weren't installed under them properly.

Only other real possibilities are a float getting hung up on the side of the bowl due to a bent hinge, being set WAY too low during the 'inverted' measurement, or being fuel saturated to the point they don't float right any more.


Oh, one other thing; if you're not running a stock fuel pump, your fuel pressure could be too high.
Old 05-11-11, 02:27 PM
  #4  
Full Member

Thread Starter
 
Zero5360's Avatar
 
Join Date: Mar 2005
Location: USA
Posts: 95
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by DivinDriver
or being fuel saturated to the point they don't float right any more.
The car sat for a pretty long time. I added some seafoam to clean up the lines. Would the Seafoam + sitting a while make the floats not operate correctly?
Old 05-12-11, 08:54 AM
  #5  
Lives on the Forum

 
Kentetsu's Avatar
 
Join Date: Jun 2004
Location: Grand Rapids Michigan
Posts: 11,359
Received 14 Likes on 11 Posts
No, it wouldn't.

Does the car have the stock fuel pump on it?
Old 05-12-11, 09:14 AM
  #6  
Have RX-7, will restore


iTrader: (91)
 
mazdaverx713b's Avatar
 
Join Date: Oct 2003
Location: Ohio
Posts: 21,710
Received 1,051 Likes on 891 Posts
if the car sat for quite a long time, i would rebuild the carb anyways. you probably have a stuck float. i have had floats literally stick to the side of the float bowl from varnished gas. it gets really messy really quick..
Old 05-12-11, 12:33 PM
  #7  
Full Member

Thread Starter
 
Zero5360's Avatar
 
Join Date: Mar 2005
Location: USA
Posts: 95
Likes: 0
Received 0 Likes on 0 Posts
It has the stock fuel pump. I took the top of the carb off to check the needles. They don't seem stuck and are also fairly springy. The carb was rebuilt in 2003 or 2004, I can't remember. I was also told a hole in the float could cause it (face->palm). I'm going to go out there right now and check that.
Old 05-12-11, 02:39 PM
  #8  
1st-Class Engine Janitor

iTrader: (15)
 
DivinDriver's Avatar
 
Join Date: Jun 2008
Location: Chino Hills, CA
Posts: 8,376
Received 26 Likes on 24 Posts
The way to check the floats for saturation is to carefully remove them, and let them soak in a glass jar full of gas (in a safe, cool place, with a loose lid!) overnight or for a couple days. If they both float equally, same amount above the gas level, they are fine.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
FbFuninthesun
New Member RX-7 Technical
3
10-06-15 08:03 AM
Jmpabon93
New Member RX-7 Technical
1
09-30-15 04:57 PM
izzolaw
Introduce yourself
1
09-28-15 06:03 AM



Quick Reply: Extreme carburetor flooding. Help please!



All times are GMT -5. The time now is 06:30 AM.