In Reply to: engine misses posted by dallas wolf on November 04, 2014 at 00:22:19:
" I have advanced and retarded the timing "
That's not your problem, but it could make things worse.
Re-set the point gap & set the timing correctly at the 1/4" mark.
Got a jig? Makes it easier.
Check the bushings for wear (tip # 68) and the advance weights while the distributor is off.
Having all new parts doesn't always mean they work. Or that they were installed correctly.
Start w/ the simple stuff.
Re-gap the old plugs & put them back in.
If that doesn't work, re-adjust the carb.
Make sure the tractor is at operating temp; that usually takes 10 – 15 minutes at idle depending on ambient temp.
Both Ford and Marvel/Schebler (assuming you have a M/S carb ) say to set both the side-pointing idlemix and the down-pointing mainjet to 1-turn as a starting point. I set the down-pointing mainjet to 1-1/2 turns and don't fool w/ it until the final step.
Then adjust the side-pointing idlemix for fastest idle; not the smoothest idle.
Next, adjust the behind the carb idle-speed set-screw for very slow 400-rpms idle.
Do that idlemix adjust for maximum idle at least 3-times. Make sure that you turn the screws slowly, like 1/8 of a turn at a time & wait a second or two for the engine to catch up. Take your time!
Do it like this:
1. Adjust idle mix jet until RPM increases
2. Adjust idle-mix set screw until the engine nearly stops (as slow as you can get it unless you have a tach that tells you 400 rpm)
Repeat steps 1 - 3 three times.
Remember the side-pointing idlemix is out for lean, in for rich.
If you do not have any problems inside the carb, it is easy to get the idle down to 350 - 400 rpms.
Your last step is to go back to the main jet. Remember, in for lean, out for rich. If you end up turning it OUT more than ½ turn for max power (remember, you already had it 1 ½ turns out) then stop right there because you have a dirty carb or a fuel problem.
Lastly, each of us has his own definition of a carb rebuild. If your rebuild did not include soaking the carb 24 hrs in a bucket of caustic carb cleaner & blowing out every orifice w/ a rubber tipped air gun, you didn't do a rebuild, IMHO. You just replaced parts.
If it's not plugs or the carb, post back w/ results & we can explore other possibilities.
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