|
Title: Idf problem or ? Post by: volksnut on December 31, 2008, 21:59:51 pm Okay I'll try to be brief....with engine warm, 3/4 intake is hot, 1/2 intake is warm at best, a/f reading is at 10.5 to 11.5 at idle, 1/2 carb is unresponsive with mixture screws will ldle up when turned in (I did remove carb and cleaned out idle circuit)...plugs are lean on 3/4 side and rich on 1/2 side? Both idle screws are adjusted 1/2 turn in at idle. If I pull the plug wires off 1 by 1 the 3/4 side shows a big difference, 3/4 side hardly any but does...no lean popping either I'm thinking the 1/2 carb isn't working, possible vaccum leak?Huh
Motor 2176 round port heads 120 cam 1 5/8 exhaust 8.5 compression 010 distributor (32 total advance) 44 idf's (floats are set 10mm/32.5) 50 idles (55's were richer than above) 135 mains (should be around 145) 200 airs F11 tubes 36 vents 3 psi fuel pressure Title: Re: Idf problem or ? Post by: Jim Ratto on January 01, 2009, 00:40:35 am easiest thing to check is vacuum leak. You know the old carb cleaner spray around base of intake. A lot of the time, intake leaks are behind crappy running, though not always.
But before you get too involved with float levels, worn out needle valves, etc... check for intake leak. Valves set? if it isn't a vacuum leak, where are the air-bypass bleed screws? Sometimes they fall out and you never notice. Or did somebody screw them in too tight and deform the carb? I think the default location should be 1/2 turn out from lightly seated. Once you get the thing running right, you can use these to equalize flow in every barrel and lean idle out a bit. how many turns out are the mixtures? (if you can get it to respond?) Title: Re: Idf problem or ? Post by: volksnut on January 01, 2009, 01:36:42 am hey Jim, carbs are new...I took apart and cleaned out and set float level before install. The bypass screws are closed, on the mixture screws on that carb...when you screwed them in to lean that barrel out the idle would go up not down, I then screwed them back out til the idle went down and the cylinder would come back when unpluging the plug wire from cap. I know this isn't the right thing to do that's why maybe someone heard of this before. I'm in the process of installing new intake/carb gaskets and clean the carb out once again.....one thing I did notice tonight while taking the carb apart was the idle mixture screw was leaking fuel past the o ring, the spring was soaked all the way to the screw slot...do these thing drip? Kind of weird no
Title: Re: Idf problem or ? Post by: John Rayburn on January 02, 2009, 02:16:31 am It's sounding more like a leaking needle valve on the rich of the engine.
|