the never ending project. 71 super build

Yak about stuff. Just stuff.
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schwim
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Re: the never ending project. 71 super build

It sounds fantastic! Have you gone for your first drive yet?
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Super_Randy
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Re: the never ending project. 71 super build

it sounds better in the video than it did when i was running in the cam/lifters. although iv been working on it all day. the timing was way ass off and the carb was out of adjustment (more on that in a moment).
haven't driven it yet. in theory i could take it around the block. iv got 145 tires on the rear right now and they do "hold air" (my spare and one bald leftover front tire) i really don't want to drive on those (waiting to hear back from JBugs about some 5.5's). i also need to adjust the clutch. it's so loose right now i can't disengage it.

so anyway back to tuning. iv got the timing set. its bouncing around a bit at idle but it's at 8 to 10 degrees and 30-32 at 3000rpm so it's good.
the carb on the other hand won't adjust.
the fast idle screw is acting up. it's not real constant. it's supposed to go all the way in so it's JUST touching the cam and then you give it another 1/4 turn. problem is i don't think it's holding the throttle plate open enough. it's only supposed to be open about .004 and i don't think it is. not only is it not open it feels like it's sticking shut. so idk wtf.
then the air volume screw, goes in to bottom out (gently!) and then comes out 2.5 turns and that's it's starting point. that's all find and good.
then you use the big bypass screw to set idle at 850rpm but it's not really having any effect whatsoever. i can play with it and get it to idle somewhat smooth at about 650rpm. i can thread it all the way in and actually kill the motor from low idle or i can back it out to a very ruff 600-700rpm idle with a major sucking sound coming from the carb (it's very loud). i put my thumb over the screw to seal it just to see if there was air leaking around it, made no difference. so idk wtf.
currently consulting manuals.

also wondering if i need to change jets cause this engine does have a SCAT C20 cam.
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Super_Randy
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Re: the never ending project. 71 super build

todays experiments go as fallowed.
1. silicone the vacuum ports on the carb just in case the vacuum hose with a screw in it was leaking. no idea where one of those ports even goes.
2. replace the o-ring on the bypass screw. old one was rock hard and had possibly shrunk, i had a spare from a rebuild kit that was still good. and is now a much snugger fit.

so maybe later today after my neighbors party is over and the silicone has time to dry a bit ill give it another shot.
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Maddel
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Re: the never ending project. 71 super build

Hey Randy this is awesome - another milestone accomplished! 8-)
Last time I tuned a 34pict was 25 years ago... And I was no fan of this thing.
I'm afraid can't help with some further tips but the new bypass screw o-ring may fix the problem.
I guess you ran this distributor & carb combo before (back in the day) and it worked well?
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Super_Randy
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Re: the never ending project. 71 super build

Maddel wrote: April 9th, 2023, 4:02 pm Hey Randy this is awesome - another milestone accomplished! 8-)
Last time I tuned a 34pict was 25 years ago... And I was no fan of this thing.
I'm afraid can't help with some further tips but the new bypass screw o-ring may fix the problem.
I guess you ran this distributor & carb combo before (back in the day) and it worked well?
works, but not well. the 009 distributor and 34 pict 3 carb issues are well known. iv been running the combo sense 2000 while learning and making small improvements over the years. had it working decently and then started having issues that i thought were ignition/carb related but now i know probably weren't. this exact carb is relatively new to me. as i was messing with it the volume control screw in my original German carb the screw jambed up and broke off so i got this lightly used aftermarket replacement and ran it for a very short time before my last engine gave up the ghost. so these parts have all worked together on my engines before.
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Super_Randy
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Re: the never ending project. 71 super build

the new o-ring seems to have helped. the bypass screw seems to perform a function, although not much of one. also found a slightly loose sparkplug. it's now idling somewhat smoothly at about 900rpm. it fluctuates about 80rpm. im now seriously wondering if the issue is jetting. it's jetted for a stock cam and now it's got a SCAT C20. although i would think it needs more jet, but while not smoking, it does smell a bit rich already...
also pretty sure i have the fast idle screw to far in, but if i back it off the idle sucks.
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Super_Randy
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Re: the never ending project. 71 super build

clutch is adjusted. it's money. nice and smooth. perfect amount of play in the peddle. im happy.

now for the im not happy.
damn back half of the brake reservoir was empty (i filled it) not sure if the lines were empty or not. i thought the back half of the reservoir went to the front brakes (?) those are locked up (or at least stuck)
i know the drivers side rear is working. passenger side not so much (they're sticky but spin and the peddle does nothing) don't know about the fronts yet. ill have to look at those when i have some help tomorrow (hopefully)

what i find odd is the brakes look dry. and there's an "access panel" (hole in the tunnel) and i pulled the carpet and looked through that and the tunnel by the master cylinder is dry. iv never seen a fluid spot under the car. so idk where it could be leaking from.

...unless brake can fluid evaporate cause my reservoir cap is cracked so it was more open than just the small vent hole... :?
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schwim
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Re: the never ending project. 71 super build

Is this the part you looked into? Because a failing MC can leak the fluid into the dead space in between the inner and outer skin, making it seemingly just disappear into thin air:

Image
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Super_Randy
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Re: the never ending project. 71 super build

yeap, that's where i looked. last time the master leaked that's where it ended up. wasn't fun to clean.
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Maddel
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Re: the never ending project. 71 super build

Check the distribution joints as well as the rubber brake lines to eliminate that.
Check to which MC inlet the rear part of the reservoir is actually connected.
Then off with the correspondent drums... :evil:
Brake dust collected inside the drums may have "absorbed" some brake fluid from a leaking wheel cylinder.
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