Spark Issues

[ratnester]

I use my 2N a couple of times a week. It's been running well until this week. I believe it's a spark issue.

I checked the coil with a light probe and it pulses with the engine turning over. I can take a plug out and see a yellow spark but I am not getting spark with a tester opened to about 3/16th to 1/4 inch. I know this has been discussed before but I can't find the post. What should I try or do next?

 

[old]

Clean and adjust the points is a good starting point.

 

[Bruce (VA)]

The number one cause of a weak spark is a weak battery.

You should see battery voltage at the top of the coil w/ the points open &about half that if they are closed.

Battery voltage means 6.35 volts on a 6v system or 12.65 on a 12v system.
75 Tips

 

[ratnester]

Thank you. I charged my battery today and took off the distributor and cleaned/set the points. I tried to take a meter reading and I believe there is plenty of volts at the coil (6.45).

I got it to start, but I had to choke it much more than usual. I thought the carb might of got dirty so I took it off and cleaned it too. It didn't appear to be very dirty on the inside.

It started back up and ran real smooth at idle. After a few minutes, I revved it up and each time it would start to stumble real back about 1/2 - 3/4 throttle then backfire. It did this repeatedly when throttling up. I did marked the plug wires so I made sure to get the back on the right spot. It has never done that before. What should I look at next?

 

[old]

When it starts to backfire does choking it hurt or help. If it helps that means it is running to lean so open the main jet a little bit till it smooths out

 

[Eman85]

Did you do the fuel flow test by removing the plug at the bottom of the carburetor?

 

[Jim L WA]

I don't want to see you throw parts at it, but if the fuel flow test is good and making the fuel mixture richer doesn't help, because you said you can't get a spark to jump in the spark tester I would be suspecting the coil.

 

[ratnester]

I didn't try the fuel test until this morning. I think that's the problem. It was very slow coming out of the carb. I took the gas line off next and no change with flow.

I took the bowl off and cleaned. I turned it on and could blew compressed air back into the tank but the flow is still slow. The valve, tank, and cap are just a couple years old and very clean.

It will rush out for a couple of seconds then I can hear air (had the cap off) then go really slow again. I tried to fill a bean can and after a minute I only had an inch.

I am currently draining the tank and plan to take the valve off and inspect everything. I hope that's it, I really need to mow!

 

[Mad Farmer]

(quoted from post at 14:08:00 04/30/22) I didn't try the fuel test until this morning. I think that's the problem. It was very slow coming out of the carb. I took the gas line off next and no change with flow.

I took the bowl off and cleaned. I turned it on and could blew compressed air back into the tank but the flow is still slow. The valve, tank, and cap are just a couple years old and very clean.

It will rush out for a couple of seconds then I can hear air (had the cap off) then go really slow again. I tried to fill a bean can and after a minute I only had an inch.

I am currently draining the tank and plan to take the valve off and inspect everything. I hope that's it, I really need to mow!

If the screen inside the tank is gunky you might want to give the inside of the tank a bath.