I've done a search to no avail and the instructions on Holley's website won't open. Can anyone provide a step by step installation procedure for a 4160 with electric choke?

JamesC

 

It's fairly simple but you need to have some attention to detail or you can really botch it up.....

There are 2 screws that hold the secondary vacuum diaphragm (hereafter referred to as the "SVD", becuase I don't feel like typing out the long version again!) to the main body of the carb, plus the little clip that retains the SVD pushrod to the secondary throttle shaft arm. Remove all, it pops right off (electric choke won't be touched- it stays put).

When you take it off you'll notice a little cork o-ring where a vacuum passage on the the back of the SVD mates with a matching passage on the main body of the carb- PAY ATTENTION TO THIS! You will need to replace this with the supplied gasket in the same location. Failure to do so will result in NO secondary opening at all- that's where the vacuum signal comes from.

Holding the SVD UPRIGHT, remove the 4 screws that hold the flat lid of the stock SVD in place. Remove the lid- there will be a spring stuck to a little nipple on it's underside. Place all this aside and turn your attention to the main body of the SVD. There will be a rubber diaphrgm laying in there with the pushrod sticking out the bottom of the SVD. Remove and set aside. Don't put the main body down or turn it over yet!

You will see a vacuum passage in the main body of the SVD (4 lid screw threads + 1 vacuum passage near one of the screw threads). THERE IS USUALLY A BALL BEARING IN THERE- DO NOT LOSE IT- YOU MUST PUT IT BACK IN WHEN YOU REASSEMBLE AND THEY DON'T USUALLY GIVE YOU A SPARE IN THE KIT!!!! You can invert the SVD and it'll usually drop right out. Cleaning it and the vacuum passage out with a shot of carb cleaner is a good idea.

Now you're ready to reassemble with new parts......

Put the ball bearing back in it's vacuum passage in the SVD. Pop the new supplied diaphragm into an "umbrella" shape with the outside edges pointing down (not up, in a cone shape). This helps immensely getting all the gasket holes to line up with the screw holes later- trust me! Now gently place the new rubber vacuum diaphrgm/pushrod into the SVD, making sure it stays in the "umbrella" shape. It only clocks one way in the housing (well, 4 ways, but it'll only work one way!). Make sure the vacuum passage in the diaphragm lines up with the vacuum passage you jsut dropped the ball bearing into.

Now put the new/supplied lid on (not the little quick change lid- leave that off for now), making sure that the vacuum passage in the lid is ALSO clocked in the right direction to line up with the vacuum passage. Spend some time making sure all 4 bolt hoes in the gasket are lined up accurately with the screw holes in both the SVD and the lid- you don't want the screws to catch the rubber gasket and tear it while you are installing them. This takes as little practice if you've never done it before so give yourself some time and maybe a few tries before you're confident you've gotten it right.

Now install the complete SVD assembly back onto the main body of the carb- DON'T FORGET THAT LITTLE CORK GASKET ON THE BACK OF THE SVD!!! Many don't know that the cork gasket supplied in the kit looks like a 1/4" square of cork and it confuses them. DON'T USE THE WHOLE SQUARE. The round cork piece is die-cut into that square- you can peel it right out of the quare. And it's got a peel-off backing which you also want to remove- it's sticky on the back so you can easily stick it to the back of the SVD before installing the assembly. There's even a little round depression in the back of the SVD where it drops right in. Easy once you know how it works, right?

OK, now the easy part..... installing the spring and the quick change lid.

Remove 2 of the 4 lid screws where the quick change lid attaches to the main lid. The quick change lid can only go on one way as one of the lid screws is now under the air cleaner flange of the carb's main body and inaccessible. These quick change lid screws will be longer as they must reach through the quck change lid, main lid and down into the SVD. They are supplied supplied with the kit.

Put the supplied square-shouldered o-ring gasket into it's groove on the top of the main lid. THis gasket seals the quick change lid to the main lid. Failure to properly install this gasket will result in NO secondary opening.

Install the vacuum secondary spring onto it's post on the underside of the quick change lid. There's a little nipple that it lightly snaps onto. When it's on properly it will stick straight out and you should be able to invert the lid without the spring falling off. It hangs on there. I recommend you reinstall the factory spring for starters (usually a Plain color spring), just to basline things.

When you put the quick change lid/spring onto the SVD make sure the bottom coil of the spring seats correctly into the metal cup in the bottom of the rubber diaphragm. Don't get it cockeyed or it wont work right and might rip the diapragm. Press the quick change lid gently straight down onto the o-ring and hold it there with one finger while you reinstall the 2 lid screws that retain it to the SVD.

Done.

I haven't done one of these in a couple years so that was just from memory, but I think it's all correct.

 

JamesC