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

Clean carb = bad idle?

Thread Tools
 
Search this Thread
 
Old 12-23-03, 01:00 PM
  #1  
Senior Member

Thread Starter
 
Lotus00's Avatar
 
Join Date: Jun 2002
Location: Minnesota
Posts: 558
Likes: 0
Received 0 Likes on 0 Posts
Question Clean carb = bad idle?

Yesterday I found a can of carb cleaner in my garage and decided to use it. I have the stock Nikki carb, never been rebuilt (I was broke after rebuilding my engine, and havent really had any money to spare since...).

The car used to idle at 1500 RPM, but now that the carb is clean it idles at 1000 RPM. The idle is less consistent than it was before, the needle bobs up and down a little and if I am not moving it will slowly idle down and die. If I am moving, it idles just fine (still inconsistent though).

Before I cleaned it, the idle was very consistent. The needle never moved from 1500, but the engine vibrated pretty bad. The vibrations are gone now, even if I hold it at 1.5k.

What do I need to adjust, and why did cleaning it cause problems? The engine is a street port 12a with racing beat header and pre "silencer "
Old 12-23-03, 01:52 PM
  #2  
I read your email

 
inittab's Avatar
 
Join Date: Jan 2002
Location: NW New Jersey
Posts: 2,624
Likes: 0
Received 1 Like on 1 Post
There is something else wrong with your carb. I'll bet you have a big vacuum leak. Check the anti-afterburn hose and the shutter valve. A well tuned rotary will idle smoothly at 600rpm. I believe that 750pm is recommended. Good luck!
Old 12-23-03, 02:07 PM
  #3  
it WILL run

 
wwilliam54's Avatar
 
Join Date: Dec 2002
Location: Raleigh,MS
Posts: 2,017
Likes: 0
Received 0 Likes on 0 Posts
check the sparrk plugs and see if they are fouled
Old 12-23-03, 02:51 PM
  #4  
Rotary Enthusiast

 
rhinor61's Avatar
 
Join Date: Mar 2002
Location: California
Posts: 822
Received 0 Likes on 0 Posts
WOW 1,500 RPM was your idle. By spraying carburetor cleaner down it you got it down to 1,000 RPM.

I would check for vacuum leaks, also spray some lubricate like LPS on the cables and linkage at the rear of the unit.
Old 12-23-03, 08:46 PM
  #5  
Senior Member

Thread Starter
 
Lotus00's Avatar
 
Join Date: Jun 2002
Location: Minnesota
Posts: 558
Likes: 0
Received 0 Likes on 0 Posts
I kinda figured I had some vac leaks, the hoses are all old and cracked. When I get some $$ I will pick up some hoses and get rid of the rats nest all together. I really hate that ugly pice of crap.

I am pretty sure that I am going to need to adjust the idle speed, when the engine was rebuilt we set it to 1.5k.

Shouldnt it idle a little higher than stock because of the extra overlap with the street port? I think I remember hearing something about this, but it could be wrong.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
alphawolff
1st Generation Specific (1979-1985)
17
11-17-15 05:57 PM
pzr2
General Rotary Tech Support
1
08-15-15 08:29 PM



Quick Reply: Clean carb = bad idle?



All times are GMT -5. The time now is 04:08 AM.