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Not running right, lots of soot, backfiring through carbs

Posted: Wed May 22, 2013 6:02 pm
by audiocontr
I had an extremely difficult time starting the pinz one day after a heavy rainstorm. I figured it was a mix of the carbs needing new gaskets and moisture in the distributor.

I cleaned out the moisture and rebuilt the carbs.

The truck started quickly! No need to pull a choke. I adjusted idle to where it was a little lobey and it seemed to rev well. Timing at 5 degrees btdc. Test drive created HUGE backfire out of both carbs, no acceleration, and a difficult time shuttiong down (both carbs smoked for a few seconds after shutting down).

I popped off the cap and its FULL of oily soot as well. Is it sucking it up through the engine?

1) Will the truck run if i placed the distributor in 180 degrees out of sync?
2) Why would there be oil residue inside the cap?? Contacts seem very scorched/burnt
3) What causes the exhaust to create soot? too much fuel? I have the external mixture screws, each turned out 1.5 turns and a decent 900 rpm idle

Re: Not running right, lots of soot, backfiring through carb

Posted: Wed May 22, 2013 7:15 pm
by audiocontr
add more detail

Mixture jets all the way in - Runs better. Idle screws all the way out - doesnt stall!!!

I messed up something.

Do the butterflies have a up or down side? They can go on 4 ways theoretically. Does it matter?

Re: Not running right, lots of soot, backfiring through carb

Posted: Fri May 31, 2013 12:45 pm
by spandit
Soot indicates truck running too rich (i.e. too much fuel or not enough air) - have you cleaned your air filter lately?

Have you checked the levels in the float chambers? If you "rebuilt" the carbs then you might have damaged the floats or made them stick...

Re: Not running right, lots of soot, backfiring through carb

Posted: Fri May 31, 2013 2:33 pm
by audiocontr
Butterflies were upside down. =)

Re: Not running right, lots of soot, backfiring through carb

Posted: Fri May 31, 2013 10:15 pm
by McCall Pinz
Did you see what I meant about the angled edges? :?

Re: Not running right, lots of soot, backfiring through carb

Posted: Sat Jun 01, 2013 5:18 am
by audiocontr
Yup, sure did. I'll need to replace them now I think.