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8N only runs when 1 spark plug lead is disconnected!?

R

riddleyo

New User
I have a 51 8N with a side mount distributor. I had the tractor running last year but it has always been hit or miss with starting. Would only run when I turned the distributor full advanced. This year it wouldn't start at all. So I put on a new cap and rotor but it was running very poorly and still extremely hard to start. I then put a new coil and new points. I have never really done points so I did my best to adjust them to 0.25 with the supplied feeler gauge. After that, the tractor wouldn't start at all. Then I did what in hindsight is a mistake - I reset the distributor and timing according to the manual. Tractor still doesn't start. Verified that there is a bright blue spark from the coil. Verified the spark plugs are sparking when laying on the head. Took off the gas tank for easier access so I am starting the tractor with a funnel and a rubber line now. However, what is most curious is that when a take the lead off #1 cylinder, the tractor starts almost instantly! A little stumbly, but not too bad. Then when I reattach the lead to #1, the tractor dies. Next, I took off the spark plug lead to cylinder #2 and the same thing occurs. Starts right up, stumbles, but when cylinder #2 lead is reconnected the tractor dies. I figure there is something wrong with the timing of the spark. My firing order on the cap is 1-2-4-3. Does anybody have any ideas on what to try next or how to appropriately troubleshoot the problem?
 
(quoted from post at 16:57:36 06/10/18) I have a 51 8N with a side mount distributor. I had the tractor running last year but it has always been hit or miss with starting. Would only run when I turned the distributor full advanced. This year it wouldn't start at all. So I put on a new cap and rotor but it was running very poorly and still extremely hard to start. I then put a new coil and new points. I have never really done points so I did my best to adjust them to 0.25 with the supplied feeler gauge. After that, the tractor wouldn't start at all. Then I did what in hindsight is a mistake - I reset the distributor and timing according to the manual. Tractor still doesn't start. Verified that there is a bright blue spark from the coil. Verified the spark plugs are sparking when laying on the head. Took off the gas tank for easier access so I am starting the tractor with a funnel and a rubber line now. However, what is most curious is that when a take the lead off #1 cylinder, the tractor starts almost instantly! A little stumbly, but not too bad. Then when I reattach the lead to #1, the tractor dies. Next, I took off the spark plug lead to cylinder #2 and the same thing occurs. Starts right up, stumbles, but when cylinder #2 lead is reconnected the tractor dies. I figure there is something wrong with the timing of the spark. My firing order on the cap is 1-2-4-3. Does anybody have any ideas on what to try next or how to appropriately troubleshoot the problem?
Click to expand...

Number 1 is closest to the radiator.
 
1-2-4-3 CCW and hope I'm correct in assuming that you intended 0.025 rather than 0.25, as otherwise there would be no spark at all.
 
1-2-4-3 CCW and hope I'm correct in assuming that you intended 0.025 rather than 0.25, as otherwise there would be no spark at all.
Click to expand...

You are correct, I meant 0.025. I get a pretty hot bluish spark.
I attached a picture of my distributor and coil connections. Can anybody take a look and see if you spot any errors.

I'm thinking about ordering another cap and trying it out.
mvphoto18084.jpg
 

You have not Verified spark yet laying a spark plug on the head don't mean chit, the color don't mean chit either... Get a spark tester and knock that part out without a doubt...
 
#1 cylinder is closest to the radiator. 2-3-4 to the rear after that.
I can't tell for sure from the pic if that's the way you have them.
 
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