Slant six carb problems

-
604

604

Well-Known Member
Joined
Jul 7, 2011
Messages
1,128
Reaction score
28
Location
Brooksville, KY
Ok,
My wife finally got on me to get the 270 dart going. And since we have had it it has had an idle problem. Give it gas and it runs like a banchy. But to get it to idle you have to turn the speed up pretty high. If you look down the carb it has fuel coming out the main system. Seems to me this should not be. So I rebuilt the carb as the guy that had it before me did. And well he should not touch anything mechanical.

Any way it still dose the same thing. Fuel dripping off the little bars in the throttle in the carb.
Float is set correctly. Even tried it at deferent heights with no effect. Also flattened out the warped economized plate so it would seal better as it was warped. Just about ready to find another carb to try. Unless any one has any ideas of something to check?

Thanks!!
 
604 said:
Ok,
My wife finally got on me to get the 270 dart going. And since we have had it it has had an idle problem. Give it gas and it runs like a banchy. But to get it to idle you have to turn the speed up pretty high. If you look down the carb it has fuel coming out the main system. Seems to me this should not be. So I rebuilt the carb as the guy that had it before me did. And well he should not touch anything mechanical.

Any way it still dose the same thing. Fuel dripping off the little bars in the throttle in the carb.
Float is set correctly. Even tried it at deferent heights with no effect. Also flattened out the warped economized plate so it would seal better as it was warped. Just about ready to find another carb to try. Unless any one has any ideas of something to check?

Thanks!!
Click to expand...

well it sounds like fuel is coming out of the mains because you have the idle so high it into the main circuit...

so i would first do a valve adjustment .010int/.020exh
reset timing from 5-10* adv.
reset the idle mixture screw @ 1.5 turns out

and go from there...

as moto said check for leaks and make sure the carb is bolted down... they tend to loosen and move around.
 
Yea kinda what I thought. But the fuel is coming out of the main circuit even with it idled down, and it will not stay running. Floods it out. If I screw the idle way up it runs fine. But if you screw the idle speed screw out it dies. Timing and valves are set dead on. No vacuum leaks. All new gaskets. It is like something in that valve plate in the carb is not working right and letting fuel come out the primary. I did check with it running and fuel level is correct. I am some what stumped.
 
604 said:
Yea kinda what I thought. But the fuel is coming out of the main circuit even with it idled down, and it will not stay running. Floods it out. If I screw the idle way up it runs fine. But if you screw the idle speed screw out it dies. Timing and valves are set dead on. No vacuum leaks. All new gaskets. It is like something in that valve plate in the carb is not working right and letting fuel come out the primary. I did check with it running and fuel level is correct. I am some what stumped.
Click to expand...

did you check fuel pressure? pump might have freaked and is blowing the needle off the seat OR the float is getting soaked with fuel and sinking...

and what do you mean valve plate? there is the throttle blade and choke plate...
 
805moparkid said:
did you check fuel pressure? pump might have freaked and is blowing the needle off the seat OR the float is getting soaked with fuel and sinking...

and what do you mean valve plate? there is the throttle blade and choke plate...
Click to expand...

Thanks,

The economizer plate. The plate-casting that holds the jet.

Took the cover off the top of the float bole with it running and the fuel is at the correct level. So the float is not sinking.

Could there be something stuck or not sealing in the jet plate?
 
i had to get my 65 manual to see what you were talking about! but i see now!

ok you said you rebuilt it?

did you set the float with the carb upside down?

also is the vent for the bowl (right above the upper screw) open at all? is that rod locked up?
 
Yep float upside down, and vent works correctly. But I must say I do not see the point of the vent. As it is also vented at the top of the venturi. These little hollys are some strange contraptions!

Thanks!!
 
604 said:
Yep float upside down, and vent works correctly. But I must say I do not see the point of the vent. As it is also vented at the top of the venturi. These little hollys are some strange contraptions!

Thanks!!
Click to expand...

how about the economizer thing on top of the carb... it looks like a power valve, so if it isn't working right it would just dump fuel....
 
you can check the wet fuel level by removing the economizer cover and measuring to the fuel, should be 27/32 from the flat surface. you also want to make sure you have used the correct gaskets from the kit, sounds like some of the idle ports may be blocked (may be fuel or air ports) most kits come with several different gaskets for different applications. also check this page for carb operation and servicing:
http://www.slantsix.org/forum/viewtopic.php?t=33102
 
I checked the fuel level by taking the economizer out. It is spot on. The only real gasket in the kit was for under the economizer, and the jet block. And all passages lined up spot on. Not sure how to test the economizer?

Thanks!!
 
sounds like the idle circut is not working properly. when you rebuilt the carb did you make sure that all the pasages were open? get a can of carb cleaner with the little tube, spray it into all the pasages to get them clean. concentrate on the ilde circut, not the econimizer or the main circut.
 
Looks like I got it figured out. The hole in the jet plate that is for the idle circuit had something blocking it. I think something slid under that pressed in plug on the top of the block. I could not get it to move so I drilled it out. Now it is running pretty darn good. Still need to do some tweaking, but I was to busy getting the GT ready for a car show in the am.

Thanks for all the help!!!
 
You must log in or register to reply here.
-

Back
Top