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Anyone ever seen a Holley 4160 with a vacume leak through the throttle shaft? If so whats the fix for this? One of my friends was over while I was tunning my carbs and he said its a common problem with holley carbs but the whistle it makes at an idle is enough to drive me insane. I havent had a chance to really be sure that this is exaclty where the leak is coming from I think it could be the manifold itself. Im using a Weiand tunnel ram and the way the top bolts on is kind of lame in my opinion. It has 2 square holes directly under each carb with a total of 4 bolts (2 bolts for the front and 2 for the back hole. I did make a test run in it even though I probably shouldnt have knowing it has an air leak. It runs like a dog until it gets up around 3000 rpms as can be expected with a tunnel ram and then once it gets into its operating range its like a 2 stroke motorcycle hitting the power band it comes to life and you better be prepared for it.

well to make sure it the throttle shaft thats the air leak, spray some carb cleaner on that spot and any other spots that you think are a leak. if the idle changes when you spray the stuff, then youve found the leak.

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"but its that gut feeling of you're drawn to what feels right for yourself and what you're passionate about..."

Holley's are notorious for throttle shaft leaks. get a can of carb cleaner and use the red straw and shoot it at the shaft and see if you can confirm thats where the leak is. sometimes a bad gasket between the throttle plate and the venturi's will mimmmick a shaft leak. hate to say it but once the shaft bushings are worn out, either get a new carb or spend the $$$$ to have it rebushed. the other option is to hammer a lead shot into the air bleeds and then use a punch to "massage" the airbleed to where the combo of throttle shaft air leak and the semi-plugged off air bleed provide the right amount of air for it to idle correctly. PM me if this is not clear and i will give you more details. it sounds like a cheezy solution but its widely used.
Newer style holley HP carbs are more tuneable and have a jet in the airbleed that u can change out

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1978 LUV Truck 2WD
450 "Small Block" Chevy
3.70 Ford 9
28x10 Goodyears

I havent had a chance to check it out yet. If one of the carbs are leaking Im going to be pissed because everything is brand new right out of the box. Hopefully I will get some time tomorrow to look into it.

Better hurry, cuz come friday, I wanna see that thing runnin

Well If it rains tomorrow I can say I will be off work for the rest of the week and that will give or should give me plenty of time to get it ready. I think part of me has been letting it slide for a while now because the weather has been crappy and it cant go out in the rain. So tomorrow its time to get serious and make it go. The othe day when I drove it home I cought a break between the rain it was a handfull

Well I hope you get your break and are able to get the stuff done you need. I have been doin some fine tuning on my truck here in the last day or so, ever since I got done helping Dennis with his truck. Im trying to finish a little detail work on the inside, and do some touch up on my paint. Looks like I wont be gettin the airbrush work done before the meet Oh well, I am still lookin forward to this meet, rain or shine!!! Screw it

Yeah Im looking forward to the meet too and I am going to be dissapointed if I cant drive my truck. I wish I was further along with my truck its not going to be in line for any awards this year thats for sure it looks pretty rough right now.

well if its all new out of the box and you suspect a vacuum leak then my first inclination would be to check the carb's base gasket. next would be the manifold gasket (between the tunnel ram base and the heads). next would be the gasket or seal between the top and bottom of the ram. does it pop and fart when you try to accelerate? what you are describing (only performs at 3000+) is most likely a vacuum decent size leak but throttle shaft is the least likely given that they are new carbs. use the carb cleaner to isolate it.

Damn my 450 heads are taking to long so I'm going to my backup motor. i wish i could get to this Nor Cal LUV meet.

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1978 LUV Truck 2WD
450 "Small Block" Chevy
3.70 Ford 9
28x10 Goodyears

yes it does kind of pop and fart at low rpms like when you take off from a stop. The main obvious reason why I suspect a vacume leak is because at an idle it whistles pretty loud. Hopefully it will rain tomorrow so I dont have to work and i can go at it with a can of carb cleaner. I hope its something like a carb base gasket I really dont want to have to remove the manifold from the heads.

Gots the fingers crossed for ya brother!!!!!!