Running Rough

[Anonymous]

I have a 65 200 w/a newly installed rebuilt Autolite 1100 carb. The engine starts OK, but runs rough w/some backfire. I am trying to get it to run steady for a while until I can rebuild. Any suggestions would be appreciated.

Thanks,
Mark

 

[Anonymous]

What was it doing prior to the rebuild? What have you tried so far?

 

[Anonymous]

It has not been rebuilt yet - I did check the compression yesterday and got a small 60 & 65 across the cylinders. This is obviously not good. There is no loss of oil or burning of oil through the exhaust that I can see - could that point to head gasket, bad valves or a combination of the two???

Mark

 

[Anonymous]

Sorry I meant how did it run before the rebuilt carb? Where is the timing at? Check for vacuum leaks. That compression is really low but at least it is equal across, did you do a wet and dry compression, hot and cold. These guys were able to diagnose my problem when I gave them that information. What do the plugs look like? Are you running point's or electronic. Have you changed the plug wires, cap and rotor? Please give as much information as you can.

don

 

[Anonymous]

Sorry - the timing is at 12. There does not seem to be a vacuum leak. The compression numbers were from a cold engine. What is a wet or dry test?? The plugs look decent - #3 did have some oil on it. Currently I am running points - would like to switch to electronic though. New cap, rotor wires and plugs.

Mark

 

[Anonymous]

Still like to know what made you put on the carb, was it the same problem?

To do the wet you put a tablespoon of oil into the cylinder and let it set for 60 seconds, then do the compression check. Do one at a time, this tells you about the rings.

Doing both tests hot and cold give more diagnostic information. It's time comsuming but easy to do and cheap

Was the timing set with the vacuum plugged?

 

[Anonymous]

OK - I doublechecked the timing - and it was off. I reset and the engine does run smoother now. I still have to do the wet compression test. What are your thoughts on electronic ignition. Would the Ignitor II w/ a new coil be the way to go?


Mark

 

[Anonymous]

The Petronix or DS2 are both excellent solutions, I have used both. I am using the DS2 with GM module now. There is a wealth of information here about both, just do a search. Whichever you choose be sure to run 12 volts off the back of the ignition to the coil eliminating the resistor wire. Either will be a great upgrade.

 

[Anonymous]

porters11,

I'm just carrying water until some of the smart guys get here. I think it's slow because of the holiday. Keep us posted.

 

[Anonymous]

Comet -

Thanks for your help so far - I'll give it a day or so and look for more responses.


Mark