383 backfires on passenger header at big end

Old 10-21-2010, 08:02 PM
  #1  
nutup
Junior Member
APPRENTICE
Thread Starter
 
Join Date: Sep 2010
Posts: 13
Default 383 backfires on passenger header at big end

after a quick rev with rpm dropping I have a back fire in passenger header I has never done this before timing is good. Could a valve be out of adjustment I have poly locks and a stud girdle
nutup is offline  
Old 10-21-2010, 09:01 PM
  #2  
bixblk
Senior Member
DYNO OPERATOR
 
bixblk's Avatar
 
Join Date: Dec 2004
Location: Chicagoland area
Posts: 472
Default check the valves

the popping maybe a cracked valve spring , or unseated valve. carefull I would lookin to it before racing again. pull the valve covers and check things out JMO
bixblk is offline  
Old 10-21-2010, 10:04 PM
  #3  
cepx111
Senior Member
RACING JUNKIE
 
Join Date: May 2006
Posts: 2,044
Default

Check your header bolts/gaskets, a exhaust leak will cause one to backfire.
cepx111 is offline  
Old 10-21-2010, 10:05 PM
  #4  
kwkracing
Senior Member
RACING JUNKIE
 
Join Date: Dec 2004
Location: austin texas
Posts: 729
Default

it could be many things a broke or weak valve spring is what i would check for first if it was running fine before. Also do a leak down on the cylinders to make sure the rings and valves are sealing. That will tell you real quick were the cause is
kwkracing is offline  
Old 10-22-2010, 02:00 AM
  #5  
blowninjected540
Senior Member
EXPERT BUILDER
 
Join Date: Mar 2007
Location: Michigan
Posts: 379
Default

Valve Spings X3
blowninjected540 is offline  
Old 10-22-2010, 04:22 AM
  #6  
curtisreed
Senior Member
RACING JUNKIE
 
curtisreed's Avatar
 
Join Date: Feb 2004
Location: KIEFER, OK.
Posts: 1,311
Default

I agree with Charlie. Check for header leak. Gets a large shot of fuel when the throttle is closed and when it sucks air past the flange it will ignite in the header. Mine will do it if I don't keep an eye on the bolts.

Curtis
curtisreed is offline  
Old 10-22-2010, 03:49 PM
  #7  
nutup
Junior Member
APPRENTICE
Thread Starter
 
Join Date: Sep 2010
Posts: 13
Default

you Guys nailed it loose header bolt thanks to everyone that replied
nutup is offline  
Old 10-22-2010, 04:50 PM
  #8  
Scooterz
Senior Member
RACING JUNKIE
 
Join Date: Mar 2006
Location: EUGENE,OR.
Posts: 3,408
Default

Man, isn't that awesome when it is something that simple??? If it were ME, I would have a spun bearing, wiped cam w/ several busted polly locks & a cracked head... plus a dog peeing on the front wheel too.
Scooterz is offline  
Old 10-22-2010, 07:02 PM
  #9  
nutup
Junior Member
APPRENTICE
Thread Starter
 
Join Date: Sep 2010
Posts: 13
Default

It was a simple fix I had a lot of bad thoughts too thats what is great about the forums there is so much knowledge out there and people willing to give advice
nutup is offline  
Old 10-22-2010, 07:22 PM
  #10  
Scooterz
Senior Member
RACING JUNKIE
 
Join Date: Mar 2006
Location: EUGENE,OR.
Posts: 3,408
Default

Originally Posted by nutup
It was a simple fix I had a lot of bad thoughts too thats what is great about the forums there is so much knowledge out there and people willing to give advice
Amen. Great folks here. I have learned a bunch from many of them over the years... stick around... something else will happen. LOL Welcome.
Scooterz is offline  

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service