"Missing"
 

Hi again guys:
My 1929 RPU has started to "miss" a bit, especially when not fully warmed up. I have just recently filed and re-gapped the ignition points, re-timed the engine and cleaned and re-gapped the plugs, so all should be OK. What is the most common cause of "missing"?

Re: "Missing"
 

Weak or lost spark and poor or lack of fuel are main causes of a miss. Hold the coil wire a bit out of the cap and check for a hot consistent spark.

Re: "Missing"
 

see if you can determine which hole is missing by shorting them out, then focus your attention on that particular cylinder... spark plug, intake gasket, etc , etc

Re: "Missing"
 

Even a "cleaned" plug might be defective ! Plugs are an expendable, wear out item. Always keep 1 or 2 sets of new plugs in stock. Even the CHEEPER brands of plugs work well, IF YOU USE THE RIGHT HEAT RANGE! Folks that drive with a little "GUSTO" usually don't have a "SOOTING" UP problem.
If you've ever used those old Champion Spark Plug Testers, then you KNOW the things that can go WRONG, up inside the plug, that can cause MIS-FIRING. Throw away old questionable plugs/condoms, so you're NOT tempted to use them again!
Bill W.

Re: "Missing"
 

throw away the used condoms also?:confused: you never taught me that :eek:

Re: "Missing"
 

New plugs can miss fire - if the counter person slams them down say thanks and buy them elsewhere! Or if someone hits them with a big hammer :-)
Beat you to it Bill !

Re: "Missing"
 

If it has been sitting for a while you could have a stuck valve not closing all the way

Re: "Missing"
 

Maybe I should clarify: The "missing" does not happen all the time, so it cannot be a stuck valve. There is plenty of spark, so that is not the problem either. Engine runs quite smoothly most of the time, with only the occasional "miss".

Re: "Missing"
 

May be running a tad lean, try enriching it about 1/8th of a turn.

Re: "Missing"
 

That would be my guess also.