Community Forums

gica · 09-24-2012, 03:07 PM

Hello to my fellowrv owners and non owners alike. Glad to have joined this forum.
I own a 1978 Dodge Apollo 440-3 25 footer, and at 65k miles it already has a rebuilt engine, tranny and I just did the Holley carb.
My immediate goal is to pass smog and fix the fuel gages issue with the wiring at the tank for which I already posted a question
As for the smog when I got to the place the guy told me it was running a bit high on CO and HC so I started turning that mixture screw counter clock wise till the CO went under 100 to 78 or so. But still it passed the idle on both and the CO at 2500 RPM but still failed the HC which was 4.0 with a max at 3.5, but with that mixture screw all the way out. So I'm taking the carb back to the rebuilding place to have the jets changed to smaller ones.
Still need to check the timing, am trying to locate the mark on the engine, think it's on the front passanger side below the radiator hose.
That's what I'm doing right now so if anybody has this model I would need a vaccum diagram for all the carb hoses make sure I got them right. Thanks in advance to all.

Lincolnboy2 · 09-24-2012, 03:24 PM

Welcome aboard!

You'll find many people here with a great depth of knowledge and insight.

Enjoy and hope you find the answers to you questions soon!

Skip426 · 09-24-2012, 03:42 PM

Your in the right spot for the timing marks and scale on the timing chain cover, every 383,400,413,426&440 I had was there. Check the cover very closely, the spot welds, holding the scale, may have let go due to rust over the years.
Don't melt the pistons out with too lean a mixture

. you may need two sets of jets , one for emissions test day and one for the real world.
Ignore my question about carb in your other post. Skip

gica · 09-24-2012, 10:44 PM

Im not surprised since I turned the adjustment screw counter clock forever, way above 2&1/2 turns, it must be all air and no gas now, and still failed HC at 2500RPM. They say to be at half to one turn from where it starts dying. Hopefully the smaller jets will help pass smog. I will definitelly tell the guy to give me regular size jets for after the smog. So as I was turning the CO and HC went down, but not far enough to pass smog at 2nd RPM.. But when I got home with the damn thing, water was boiling in the radiator so thanks for the boiling pistoins tip. It's been awhile since I've delt with a carb. You wouldn't happen to have a vaccume diagram for the Holley 4175 Spreadbore carburetor. Here's a Youtube clear descript on it:

Holley 4175 Spreadbore carburetor - YouTube

. Thanks

Bruce C · 09-25-2012, 04:00 AM

Wellcome to the group and good luck with that smog test. Two differennt size jets sounds like your easiest route. Good luck with the remainder of your project as well.

Steve N Sal · 09-25-2012, 05:57 AM

Howdy and welcome aboard. I'm sure you'll find all the answers you need for any project you may take on. Have a great time, be safe and Happy Motoring!!!