idle on 170

[durkzz8]

after getting everything running good on my car i hooked up a tach. To my surprise the tach said the engine was at 1500 rpm's at idle. So I made certain that this was right by making sure the switch was set to 6 cyl. Then I took the tach out of my truck and it read the same. Then I go to adjust the idle and got it down to 1200, anywhere below the engine will just shut off. My ?'s are could it be my mallory box fooling my tach? or is there a real problem? My dad said he had to make a gasket for the carb, because no one in town carried one, could it be that I need a new gasket? Thanks for the help in advance,

Chad

 

[pedal2themetal45]

I'd start by checking for a vacuum leak. check around the carb base as thats the gasket in question..
Then maybe adjust the idle down as far as you can and readjust the carb mixture and also check the timming and readjust it as you slow it down.
Does it sound fast...
tim

 

[addo]

I suspect the ignition box is giving a dummy reading. Can you disable it for testing?

 

[durkzz8]

ok i disabled the box and it still shows a high idle. as for the timing, how? Ihave no balancer and have found no timing marks. I have a gasket on the way so that will be replaced in the next few days.

 

[addo]

You must have a balancer on there. Otherwise there's nothing driving the pulleys. Can you post a picture of the timing cover and belt setup?

 

[61Futura]

I made my own gasket for the fuel bowl and that ended up screwing up my carburetor. The gasket caused small fibers to get into the jets & idle passage. The gasket was dissolving. I've got a cork gasket on it now. And have cleaned up the carb by tearing it all apart again.

As for the timing mark, I don't know what you have, but mine has the marks as part of the timing chain cover. My balancer (crank shaft pulley) has a groove or notch on the edge of the pulley that needs to be cleaned up to see it easier with a timing light. I use my pocket knife to shine up the notch. The knife helps to find the notch also. The marks on the timing cover should be at clock position of about 1:30 around the crankshaft pulley. It will mark off TDC, 3, 6, 10, & 14 degrees BTDC.

 

[durkzz8]

thanks guys, I do have the notch on the timing cover and with the timing light the notch was about 1/2 inch past the last mark on the cover. after bringing it down to 10 degrees the idle came down and no more popping out the exhaust, but idle was still high.after a new gasket and some adjustments she idles at 600 rpm's. the main reason for the high idle was because the home made gasket didn't have a slot in it for the idle and the throttle had to be open all the time. thanks for all the help guys.

Chad