1st Generation Specific 1979-1985 Discussion

Oversized carb, or badly tuned holley?

Old 10-18-2010, 04:09 PM
  #1  
Senior Member
Thread Starter
 
sen2two's Avatar
 
Join Date: Feb 2005
Location: Kissimmee FL.
Posts: 1,579
Default

I bought this 85 GS yesterday for a GREAT deal. I was told the only thing wrong was a snapped throttle cable. Check it out, and when I get there, I noticed it already had a holley carb, RB manifold, and full true dual RB exhaust. SWEET... And some other choice upgrades I keep finding...The guy didn't have a battery so i never even tried to start it. I figure, at this price, I'm taking it no matter what...



So today I fix the throttle cable and change the plugs, then do a few other precautionary things to make sure I don't ruin it on the first start up. Including spraying a bit of carb cleaner into the carb before start up. I have no idea how long it's been since it's been cranked over... Turn the key, it starts right up runs for a few seconds then dies. Try to restart, no go. Spray some more carb cleaner, boom... cranks up just fine. I continue to spray a bit of carb cleaner before each time I start it or it will not start up. So I turn the idle screw so the carb is a bit more open for start up, it cranks up and holds idle clean at 2500 for a little while then starts to die out as I am turning the idle screw down. I do this a few times and every now and again, I try to throttle it (all of this done standing over the engine, not with the gas pedal) it I throttle it really soft, it will rev up smoothly. But i have to do it very slow. if I just try and throttle it, it just bogs and wants to die.



It never stayed running on it's on more than one minute. And it will only start if I spray some carb clean before hand.



I do not know if it's a 600cfm or another size, The guy didn't even know what the racing beat manifold was called... So any guesses, to large of a carb, or badly tuned and need to be rebuilt? (by rebuilt, i mean the carb, not the motor)
sen2two is offline  
Old 10-18-2010, 05:54 PM
  #2  
Super Moderator
 
1988RedT2's Avatar
 
Join Date: Apr 2002
Location: VA
Posts: 2,532
Default

85 GS is a 12A, right? Isn't the Holley for that manifold like 390 cfm or something? Sounds like you might be on the right track. Other thing I'd want to check is fuel flow/pressure.
1988RedT2 is offline  
Old 10-18-2010, 08:24 PM
  #3  
Senior Member
Thread Starter
 
sen2two's Avatar
 
Join Date: Feb 2005
Location: Kissimmee FL.
Posts: 1,579
Default

It has a holley fuel pump and regulator also. I think it is flooding it badly...



The fuel pressure was close 7 psi. And I'm pretty sure a stock or street ported 12a with a holley will only need about 3.4 psi.





From what I have seen, a holley 465cfm carb is the best choice for a stock or street ported 12a.I'll see if i can trade this 600 for a 465 locally...
sen2two is offline  
Old 10-18-2010, 09:05 PM
  #4  
Super Moderator
 
mazdaspeed7's Avatar
 
Join Date: Sep 2002
Location: Savannah, Ga
Posts: 2,763
Default

I dont know how extensively, but I do know RB modifies the holly carbs to better work on a rotary. I dont know how good your results from a standard 465 holley will be.
mazdaspeed7 is offline  
Old 10-23-2010, 05:25 PM
  #5  
Senior Member
 
bigboi12A's Avatar
 
Join Date: Jul 2003
Location: Deltona, Florida
Posts: 293
Default

600 on a stock port is over kill. Ive seen people drill the high speed air bleeds and idel air bleeds. Their right next to the venturies,,, i think thats what thoes things are called their pressed in. Probably just on the primary side I dont know what size their supposed to be but im sure u can tell if they have been fucked with u need. a small holley 450-5 something.



Unrelated, topic Yo man r u a part of the central florida rotary club thing? Ive heard rummors about them doing a swapp meet and or car show?????? just wondering if u had some more info since they meet out your way
bigboi12A is offline  
Old 10-24-2010, 12:48 AM
  #6  
Senior Member
Thread Starter
 
sen2two's Avatar
 
Join Date: Feb 2005
Location: Kissimmee FL.
Posts: 1,579
Default

Yeah, the swap meet was today. its was OK. Nobody really came looking to buy or trade. most people only came looking to sell stuff. Was a harsh market...
sen2two is offline  
Old 12-24-2010, 10:25 PM
  #7  
Junior Member
 
bad 83's Avatar
 
Join Date: Mar 2008
Posts: 10
Default

I have ran a 600 Holley on a stockport that ran perfectly and got 22.5 mpg. It's all in the tuning. The Holley has to run at 6-8 psi fuel pressure. If you look on the front of the airhorn on the carb, you will find a set of numbers. These will tell you what model the carb is. If the numbers are 1850-***, this would indicate a 600 cfm Holley.
bad 83 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ArmyOfOne
Rotary Engine Building, Porting & Swaps
8
05-01-2011 08:56 PM
nicad2
Rotary Engine Building, Porting & Swaps
4
12-12-2005 12:07 PM
allrotor93
Single Turbo Discussion
1
01-08-2004 07:47 PM
eddierotary
Performance Mods
1
12-31-2003 06:02 PM
noriegaja2002
Performance Mods
2
10-06-2003 12:39 AM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Quick Reply: Oversized carb, or badly tuned holley?



All times are GMT -5. The time now is 06:45 PM.