Re: BACK FIRE
[Re: bonefish]
#185584
01/06/09 01:15 PM
01/06/09 01:15 PM
|
Joined: Aug 2003
Posts: 43,129 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,129
Bend,OR USA
|
Quote:
1050 dom,7al3,crank trigg. all i did was build a new short block and put everything back together,now i have to hold the trottle wide open for it to srart and it back fires through the ex.ive benn through the carb,timing ,wires a few times ,WHAT AM I MISSING(no pun intended)
The basics, valve lash set correctly, firing order with verification of every spark plug wire on the correct cyliner, distributor cap not cracked and so on. I did have one new street Hemi motor that was backfiring on the dyno due to the jetting I changed on a new set of carbs before running them on any motor, put the primary jetting back to stock from the manufacturer and the back firing stop Check the carb jets to make sure there is no trash in the jets plugging them up Same thing on the bleeds IHTHs
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: BACK FIRE
[Re: bonefish]
#185585
01/06/09 01:23 PM
01/06/09 01:23 PM
|
Joined: Sep 2005
Posts: 2,442 LOWELL IN
QWK_ENUF
top fuel
|
top fuel
Joined: Sep 2005
Posts: 2,442
LOWELL IN
|
ign timing retarded
valve not seated
cam timing
WAXER
|
|
|
Re: BACK FIRE
[Re: Cab_Burge]
#185592
01/07/09 08:43 AM
01/07/09 08:43 AM
|
Joined: Nov 2004
Posts: 7,274 s.w.fl
bonefish
OP
master
|
OP
master
Joined: Nov 2004
Posts: 7,274
s.w.fl
|
Quote:
Quote:
ok TOOK EVERYONES ADVICE AND WENT BACK THROUGH.fixed the back fire,i hate to admitt it but i had 2-4 crossed,still had to hold it to the floor to start so i took the carb back apart and i had a 4150 metring block gasket in my dommy now it starts right up.now if i can just get it to idle.
what idle speed do you want it to idle at? What brand and size Dominator are you running? Is your carb equipt with power valves or not? If so what vacume rating are you currently using and what is the idle vacume in gear?
ITS A 8896 NO PV I HAVE To TURN THE AIR SCREWS OUT 2 1/2 TURNS TO GET IT To IDLE, i need it to idle STRONG at 1500 otherwise it kills the motor when i put it in gear.
|
|
|
Re: BACK FIRE
[Re: bonefish]
#185593
01/07/09 02:45 PM
01/07/09 02:45 PM
|
Joined: Aug 2003
Posts: 43,129 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,129
Bend,OR USA
|
Have you verified that the throttle blades are open the same amount on both ends of the carb.? If not try that, it sounds like your not idling on the idle circuit now. Also, if you can, see what size the idle bleeds are now on all four corners and post that size. You should be able to have the motor idle at 1000 rpm in nuetral and drop around 100 to 200 rpm when you put it in gear. What is the initial timing at now, can you get the motor to idle at 1000 rpm and check the timing? Another easy thing to try to fix the idle is to get some small wire,.020 or smaller and make some short L that will fit into the idle bleeds to see if the current idle bleeds are to big I like to make my carbs idle at or below 800 rpm in gear and only need around 1/4 to 1 full turn out on the idle mixture screws to idle clean and not stink out the exhaust That usually requires custom tuning the idle circuits and the bleed sizes on all four corners
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
|
|