Edelbrock 1409

[Hedan]

I have a mercruiser 4.3 vortec engine with a edelbrock 1409 (600) carb.
Its calibrated with the calibration kit 1485 from edelbrock, the problem is when i hit full throttle it stumbles and the secondary upper air valve wont open all the way opens 3/4. I have checked that the valv slides smoth.
Anyone who has any sugestions what might be wrong?

 

[LAC_STS]

Re: Edelbrock 1409

I have the same carb on my 5.7


I also had the same problem with the secondary air butterflies not opening all of the way at WOT. I spoke to Edelbrock on the phone and they told me that sometimes there is not enough air flow or vacuum for the butterflies to open.

They told me to take them out and drill a small hole in the counterweight. Then recheck and if necessary drill another or drill the first one bigger.


I drilled one hole about 1/8" on each side of the weight and now they open all the way.


When I took the air horn off I noticed that the floats were a little off so I adjusted those, and cleaned it all up since it was off.


I had never touched a carb before but the Edelbrock is really easy to work on.

 

[Hedan]

Re: Edelbrock 1409

Thanx for the quick replay!!

I can agree its a grats carb, i will do as edelbrock told you and hope the problem goes away..

 

[LAC_STS]

Re: Edelbrock 1409

You can give them a call if you want. It took about 10 mins of hold time but when I got someone on the phone they were very helpful and knowlegable. Theyll talk to you for an hour if you want.


My secondary air butterflies were only opening about 5/8 to 3/4 of the way and a 1/8 hole solved it.

But maybe start off smaller and then work your way up. You cant buy the secondary air butterfly if you mess it up. I asked them on the phone. They dont offer it for sale by it self.

Just so you know.

If you set the butterfly on your index finger. (finger inbetween the butterflies) you can turn it as it would open on the carb and feel where the weight needs to come off.

Heres a pic of where I drilled my hole. One on each side.

 

[180shabah]

Re: Edelbrock 1409

OJ, how does "forcing" the air valve to open fully eliminate a stumble?

OP - is this stumble happening of you gradually reach WOT or only when you instantly open the throttle?

 

[LAC_STS]

Re: Edelbrock 1409

My problem was that at WOT my secondary main butterflies were opened all the way but there was barely any fuel coming out of the secondary jets.

I called Edel and they told me that there needs to be enough air flowing (vacuum) and that if the secondary air butterflies were not completely vertical there would not be enough vacuum to pull or make fuel come out of the secondary jets.

I had someone drive my boat while I had the flame arrestor off and the throttle at just before the secondaries opened. I operated the secondaries manually and saw that the secondary sir butterflies were only about 3/4 open at WOT. when I opened them the rest of the way a lot more fuel came ut f the secondary jets.



I think you should rule out everything else that cups possibly causing the problem before messing with the weights.

I did t because I had done just that and ruled everything else out. And my carb was brand new and only a month old with 20 hours on it.

 

[John_S]

Re: Edelbrock 1409

I have a mercruiser 4.3 vortec engine with a edelbrock 1409 (600) carb.
Its calibrated with the calibration kit 1485 from edelbrock, the problem is when i hit full throttle it stumbles and... Anyone who has any sugestions what might be wrong?

Have you tried using the different accel pump rod locations to try to get the bog out?

BTW, the 1485 kit is an exact match to the Merc weber pre-vortec 4.3L tuning. Your vortec 4.3L might need additional tuning.

 

[benoitdegrie]

Re: Edelbrock 1409

Hi everyone,

I have the same problem with my new engine equiped with a 1409.
The secondary barrel didn't open fully at WOT;
By the way, i can't reach more than 4000rpm, so, my new engine witch is supposed to give 315HP at 5000rpm give me only less than my old 350 with a holley carb and 250HP.

I'm not so glad drilling...

I read that the problem could come of the choke.

Help !!!

Regards

Benoit

 

[Bondo]

Re: Edelbrock 1409

I can agree its a grats carb,

Ayuh,.... I love 'em myself,....

If yere messin' with these carbs,... Ya gotta read This....

 

[LAC_STS]

Re: Edelbrock 1409

Hi everyone,

I have the same problem with my new engine equiped with a 1409.
The secondary barrel didn't open fully at WOT;
By the way, i can't reach more than 4000rpm, so, my new engine witch is supposed to give 315HP at 5000rpm give me only less than my old 350 with a holley carb and 250HP.

I'm not so glad drilling...

I read that the problem could come of the choke.

Help !!!

Regards

Benoit

Drilling was only a fix for if the secondary main butterflies open all the way (completely vertical) but the air butterflies don't.

You can see if the main butterflies open all the way on the trailer or at the dock. Just take the flame arrestor off and push the throttle to wide open. You can use your pinky or small screwdriver to open up the secondary air butterflies so you will be bake to see if the mains are completely vertical.

If they are not completely vertical then you have a throttle cable problem probably. Might need adjusting.

If not then you can check the secondary air butterflies.

The air butterflies do not open unless you are under load. They are jcontrolled by vacuum. To check this you need to have someone else drive your boat while you look down the carb.

Mine were only coming open about 3/4 of the way. After I drilled the hole they open fully and the correct amount of fuel comes out of the secondaries now.


I would check everything before drilling. Once you drill there is no going back. Edelbrock does NOT sell the secondary air butterflies so if you mess if uo your screwed.

 

[ibrnrbr]

Re: Edelbrock 1409

I would hook up vacuum gauge and make sure carb is tuned right. Also check rod for secondaries

 

[John_S]

Re: Edelbrock 1409

Also check rod for secondaries

There are none on a 1409. Just a changeable jet, per side.

 

[benoitdegrie]

Re: Edelbrock 1409

None of you have heard of the possibility the electric choke to block the opening of the secondary buterfly in full ?

Benoit the Frenchy

 

[benoitdegrie]

Re: Edelbrock 1409

i read that it could be a problem of alimentation of the choke.

 

[John_S]

Re: Edelbrock 1409

None of you have heard of the possibility the electric choke to block the opening of the secondary buterfly in full ?

Benoit the Frenchy

Do you mean if the choke is fully closed they won't open all the way? If so, probably by design.

Or do you mean some mfg defect that has been found on some?

 

[benoitdegrie]

Re: Edelbrock 1409

Do you mean if the choke is fully closed they won't open all the way? If so, probably by design.

Or do you mean some mfg defect that has been found on some?

I mean, if the electric choke do not work accurately, it may prevent the secondarie to open in full.
I'm lost, because the more i read the less i understand what could hapen to my new engine.
I spend lot of ??? at michiganmotors shop for this engine and they do not appear to want to help me.

My problem is that i don't find my 315 hp because i can't reach more than 4000rpm.

Everything was done by a mechanic, tinning, avance etc... but i saw by myself the problem of the secondarie barrel...

My vessel is in Spain, holidays are finished and i'm in France.

I'm now looking for some good advices.

 

[benoitdegrie]

Re: Edelbrock 1409

Drilling was only a fix for if the secondary main butterflies open all the way (completely vertical) but the air butterflies don't.

You can see if the main butterflies open all the way on the trailer or at the dock. Just take the flame arrestor off and push the throttle to wide open. You can use your pinky or small screwdriver to open up the secondary air butterflies so you will be bake to see if the mains are completely vertical.

If they are not completely vertical then you have a throttle cable problem probably. Might need adjusting.

If not then you can check the secondary air butterflies.

The air butterflies do not open unless you are under load. They are jcontrolled by vacuum. To check this you need to have someone else drive your boat while you look down the carb.

Mine were only coming open about 3/4 of the way. After I drilled the hole they open fully and the correct amount of fuel comes out of the secondaries now.


I would check everything before drilling. Once you drill there is no going back. Edelbrock does NOT sell the secondary air butterflies so if you mess if uo your screwed.

After drilling, do you note a better RPM ?
This is my principal problem.

 

[LAC_STS]

Re: Edelbrock 1409

Yes it fixed my problem. But you have to realize that drilling is the last resort. I spoke with Edelbrock and told them everything I had done and they told me that was the only option.

You have to check everything out first. Check your throttle linkage that its opening the secondary main butterflies at WOT, check that the secondaries start opening when the primaries are about 60% open, check your fuel pressure to the carb, check the fuel system for air leaks, make sure there is no water in your fuel, check your IGN system, check that your plugs are gaped right, make sure the plug wires are on right, check timing, etc, etc.


The only thing drilling did for me was make my secondary air butterflies open all the way at WOT. Doing this caused the correct amount of vacuum which in turn caused the correct amount of fuel to come out of the secondaries.


Lightning the weight on the secondary air butterflies is only a way to create more vacuum if for some reason you don't get enough at WOT. Edelbrock told me that the 1409 marine version has a lighter counter weight already than the 1405 or other auto carb, but that in some applications it still may not be light enough.

But again drilling only solves the problem of the air butterflies not opening all the way due to not enough vacuum.

ONCE YOU DRILL THE HOLE YOU CANNOT GO BACK. YOU CANNOT BUY THE SECONDARY AIR BUTTERFLY.

IF YOU DRILL THE HOLE AND ITS NOT NEEDED OR YOU DRILL IT TOO BIG THEN THE AIR BUTTERFLIES WILL OPEN PREMATURELY OR TOO FAST CAUSING A LEAN CONDITION.

ie. You will be screwed.


So again, first of all you need to have someone drive the boat while you look down the carb and check it out. Then you need to check EVERYTHING ELSE.

 

[imported_TheMan]

Re: Edelbrock 1409

I realize this is an old thread, but as I'm currently working on tuning my 1409 I wanted to make a note about what LAC states.

You won't be screwed if you do drill your butterflies, but it will never be factory original again. The weight in the butterflies can be regained by tapping the holes you drilled and inserting plugs. I still need to do more calibrating to determine if I need to modify the secondaries...