I’ll chime in here to share my recent experience with trying to extend my intake. I went to HD and bought a length of 3/4” ID 1” OD heater hose and attempted to extend my intake but couldn’t get the hose to seal down tight enough with hose clampsand got air leaks causing high rpm idle and very slow return to idle after a rev. Here is what I went for and am still convinced I can get it to work I just haven’t found a good way to get the hose clamps tight enough to prevent vacuum leaks.
I think you just need a better type of hose clamps. Jubilee clips have lots of adjustment but you don't need any, and the thread can slip if overtightened. The clamps I found are only just big enough so it's a PITA to get the bolts into the little square nut, but they do clamp up extremely tight.
Yea I’ve been meaning to ask you where did you get the clamps you are using and what are they called?I think you just need a better type of hose clamps. Jubilee clips have lots of adjustment but you don't need any, and the thread can slip if overtightened. The clamps I found are only just big enough so it's a PITA to get the bolts into the little square nut, but they do clamp up extremely tight.
I really don't remember if they had a name other than stainless steel hose clamps (in whatever diameter it is). They looked like a good type, and I'm very happy with them. I got them off eBay.
I just don’t understand why I’m getting the vacuum leaks on mine. The carb is tuned great and idles perfect. Then I slap on the 4.5” heater hose intake extension and really crank down on the hose clamps as much as I can and there still seems to be a leak because it idles real high after that and takes a while to come down off a rev.
What about the manifold fitting into the carb itself? Bevel the outside edge of the manifold slightly to a 45° angle to be a good match for the inside of the carb. Wind two turns of PTFE tape around the manifold and shove the carb on tightly.
So I did try wrapping the aluminumm stock intake with lots of Teflon tape to hope for a tighter fit with the rubber hose but it still leaked I think. Of course I’m assuming both of the hose clamps are leaking since I can’t determine if it’s just one. And I have an o ring inside the carb where it meets the aluminum intake portion I cut off so I don’t think the leak is there since it’s the same setup I use without the manifold extension and it works fine. I’m just a little bummed since I went out and bought the heater hose for $20 and hose clamps to boot. I just don’t see how there is a vacuum leak when I’m literally cranked downint he hose clamps as tight as I can get them with my ratchet. Could there be anything else making the engine act this way besides a leak at the hose connections? I’ve tried getting these damn things to work out like 5 times and always have to end up unbolting and putting the stock setup back.What about the manifold fitting into the carb itself? Bevel the outside edge of the manifold slightly to a 45° angle to be a good match for the inside of the carb. Wind two turns of PTFE tape around the manifold and shove the carb on tightly.
Maybe wind PVC electrical tape around everything lol.. Messy looking but it should work.
Well yeah, there's the intake gasket on the cylinder. You can try making a new one from a cereal box or actual gasket material.
Yea i used a 5/16" socket to tighten and ill try what you said and report back tomorrow!
