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Posted by: jimkelly Sep 5 2006, 09:58 AM

as shortly after letting off gas - bang bang bang ?

We just installed a 1.8 with single carb and 050 distributor.

Carb and dist appear to be working fine.

What are the odds that the problem is due to valves needing adjustment as this is what we are gonna try next.

Posted by: tyler Sep 5 2006, 12:35 PM

I always thouht the only cause of this could be timing but now I'm a believer that it's always more likely too much fuel that explodes in the tailpipes. My 350 did exactly what yours is doing after carb rebuid. Since the carbs were only supposed to have been cleaned and adjusted (and they seemed to be running lean), I went after the timing and valve adjustment, all to no avail. Later I found out the carb guy had put in bigger jets and didn't tell anyone. Put the old jets back in without touching anything esle and the backfire disappeared.
For what it's worth.



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QUOTE(jimkelly @ Sep 5 2006, 08:58 AM)

Posted by: ptravnic Sep 5 2006, 01:23 PM

Mine did this b/c I was running it too lean...

Posted by: smdubovsky Sep 5 2006, 01:28 PM

If its in the exhaust, then you have an air leak in the exhaust. If its poping out of the carbs/intake Id bet its too lean (which is usually caused by a vacuum leak if the carbs are jetted even close to correct). Both my TWMs and Webers will pop in the intakes on the /6s when too lean (and BOTH are due to vacuum leaks).

Best,
SMD

Posted by: ptravnic Sep 5 2006, 01:57 PM

My lean situation was due to a misadjussted FI system and poor engine build (too high of a CR). Both were completely my fault. O well, I'm in the process of rebuilding it now and will not make the same mistake(s) twice!

-pt

Posted by: jimkelly Sep 6 2006, 07:15 PM

muffler is now on and back fire is gone - hum - simple solution : )

Posted by: PORobinSCHE Sep 6 2006, 07:26 PM

QUOTE(jimkelly @ Sep 6 2006, 09:15 PM)

Posted by: jimkelly Sep 6 2006, 07:52 PM

hey - if I told you guys all the facts - I would not get such great replies : )

Thanks

Jim

Posted by: PORobinSCHE Sep 6 2006, 08:17 PM

that's why i come here!!!