Cil #3 dont burn mixture

[KEITH KRAUSE]

Re: possible coil problem... why would installing a new plug into the cap make the fat blue spark return as he says? A fouled plug can obviously deter good spark, but if the coil really is weak, then installing a new plug would still show a weak read, and #2 should also have a weak spark and similar problems.

[KEITH KRAUSE]

After your compression check and carb synch, etc, (if the compression is good) let us know what happens.
To test the choke plungers for sealing, you would have to blow into the passage that leads to the choke starter jet/tube. With the plungers down, no air should be heard to escape. Your fouling at 1/4 and 1/2 throttle positions wouldn't be choke related. The choke is bypassed as soon as the thottle is opened that far. There can be a minimal mixture change, but not enough to cause your problem.
You foul the plug at warm up with the choke because the mixture is already too rich in that cylinder. Either from a carb mixture problem, weak spark, or poor compression.
Is 24mm the factory setting for the floats. Also, the measurement should be done with the bowl gasket removed.

[Anonymous]

Re: possible coil problem... why would installing a new plug into the cap make the fat blue spark return as he says? A fouled plug can obviously deter good spark, but if the coil really is weak, then installing a new plug would still show a weak read, and #2 should also have a weak spark and similar problems.

I know Keith, and I agree. But right now switching coils is the easiest thing to do, and when I troubleshoot I try to take care of the easy possiblities first (like making sure the TV is plugged in before taking the back off.)

The carburators would be the only other possibility (if compression is good). I thought he said he already went through them. That's not saying they are good, since most people use a spray can cleaner on them. The only way to make sure passages are open is to dip them and use an air compressor. If that hasn't already been done, that would be my next step.

I'm not a carburetor expert Keith. I defer to you and others when it comes to them.

[KEITH KRAUSE]

I'm not a carburetor expert Keith. I defer to you and others when it comes to them.

I wouldn't say I'm a carb expert either. Maybe trial and error king?