# 8N Starting problems



## Aaron Forsythe (Aug 9, 2019)

Having a hard time getting my 8N started. 

Cylinder pressures: 
1 - 90 (dry) / 110 (wet). 
2 - 90/110 
3 - 85/105 
4 - 90/110. 

New: coil (12v), distributor, points, plusg wires, spark plugs, alternator, resistor (OEM), battery, carburetor, key switch, wiring, gas tank, fuel shut off, fuel line, new gasoline.

Will start and run for a few seconds then die. With choke, with partial choke, with full choke. Can feel good vacuum at carb when trying to start. I have used a spark testing tool between all 4-cyls and see light in tool when cyl fires. I have the autolite plugs in. I have adjusted the carb fuel/air screws to specs. I notice that I see gas pooling in the carb on the intake side, which I presume from reading that it is too much choke. Ambient temp when trying to start 65-75. 

Any suggestions? 

Thanks!


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## pogobill (Jan 31, 2012)

A plugged filter in the fuel system? Sticky governor?
Seems you have replaced a lot of items!?! Is this a rebuild, or are you changing parts to find the issue? The filter issue is probably a moot point with the changes you have made. Do you have a ballanst resistor in the ignition system? If so by pass it to see if the run time improves.


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## Ed Williams (Jun 13, 2019)

One additional item to check. You need 4 ohms resistance across the coil for optimum spark. You can adjust the ohms by using resistance blocks. I installed 3 blocks in series to get 4 ohms on my NAA. It starts and runs great. You can advance the timing a little to aid starting, then adjust by hand til it runs best. Gas ignition is fuel-air-spark. Need to confirm all 3.


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## Ed Williams (Jun 13, 2019)

Another thought. If you converted to 12 volt, disconnect the 6v voltage regulator. 12 v is controlled by alt and 6v reg is positive ground and really messes up the system.


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## Aaron Forsythe (Aug 9, 2019)

pogobill said:


> A plugged filter in the fuel system? Sticky governor?
> Seems you have replaced a lot of items!?! Is this a rebuild, or are you changing parts to find the issue? The filter issue is probably a moot point with the changes you have made. Do you have a ballanst resistor in the ignition system? If so by pass it to see if the run time improves.


 Yes, I had to replace a lot of parts due to varmit issues (chewed up wires) rusted out fuel tank, cracked fuel bowl, fuel line kinked and leaking, etc. I installed an original resistor on the firewall behind the tool box (which is new too due to rusted out bottom). The wire from the coil goes to one end of the resistor, the other end connects to the solenoid. Do I need to add an additional resistor in between the OEM one and the coil? 

I am not a novice at engine mechanics and all connections have good continuity. It is just this has me stumped as to why I can't get it to start. Everything I have read says they are a little grumpy about too much choke, which is what I am guessing is causing the fuel to puddle in the carb on the intake side. I use the tool that plugs on the spark plug and into the wire (I don't just lay the plug against the block to check for spark). I went with the Autolite plugs based on another video I had seen that said using a newer crossover plug would have resistance issues. 

Thanks!


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## Aaron Forsythe (Aug 9, 2019)

Ed Williams said:


> Another thought. If you converted to 12 volt, disconnect the 6v voltage regulator. 12 v is controlled by alt and 6v reg is positive ground and really messes up the system.


Hi Ed, 

It was already converted over to a 12v system when I purchased it. Everything is correct for a negative ground system. New alternator was due to rusted out inards and full of mud dobber nests. The alternator is one wire which runs to the OEM resistor on the firewall and the other end connects to the solenoid on the starter. Parts purchased from Steiner Tractor so I am not buying just any old parts from place like Walmart. 

Thanks for your help!


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## Aaron Forsythe (Aug 9, 2019)

Ed Williams said:


> One additional item to check. You need 4 ohms resistance across the coil for optimum spark. You can adjust the ohms by using resistance blocks. I installed 3 blocks in series to get 4 ohms on my NAA. It starts and runs great. You can advance the timing a little to aid starting, then adjust by hand til it runs best. Gas ignition is fuel-air-spark. Need to confirm all 3.


Hi Ed, 

That is one thing I have not checked yet - ohm resistance across the coil. Would I just need to add another resistor between the OEM resistor and coil wire to get to 4 ohms if needed? 

I have not tried to adjust the timing. I did not change the timing from the "pre-set" that is on the side tag. I was presuming that it was "pre-set" to factory setting (purchased from Steiner Tractor). I will try that next because - DOH! - sometimes settings are not correct coming out of the box (I did check points pacing though and they are correct). 

Thanks!


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## Ed Williams (Jun 13, 2019)

I did the NAA by trial and error. You can use either a 12v or 6v coil. You just have to adjust the resistance to 4 ohms. There is no factory standard on the resistance, but from all my research on 12v conversions the motor performs the best over the entire power range if the coil resistance is in the 4 ohm range. Each of the resistor blocks I used was .87 ohms. I added resistors in series until I got 4.1 ohms. The tractor started right up and has good power. I set the timing to 1 deg advanced over the factory setting which makes it easier to start without hurting performance under load. "Yesterday's Tractor" has several instructional guides on 12v conversions which are very helpful. I used a 3 wire alternator from a 76 Chevy, $30, verses the 1 wire, $70. All that is required is a 5 watt diode, side marker light, or a auto type ignition switch with the acc terminal. Hook the third wire to the acc pole instead of the extra light under the hood. This just activates the internal voltage regulator in the alternator. All this is documented in the "YT" site under 12v conversions. Interesting reading from many who have done this. My NAA had no wiring at all due to sitting many years with mice eating the wiring up. One interesting fact I found during my research is that the wiring covering for older wires is made from a soybean extract. Read that as "mouse bait". You can Google "6v to 12v tractor conversions" and get loads of information and detailed wiring diagrams and helpful tips. I was too stingy to buy the conversion kits that are grossly over priced. I spent less than $50 on the entire conversion and it has run flawlessly for over 20 years. FYI, the compression numbers you shared look really low. When I first got the NAA, compression was 140-145 on all 4 cylinders. After running for 3000 hours for the 45 years I have owned it, the latest comp test in 2017 showed 125-130 on all 4 cylinders. Most sites recommend overhaul if comp falls below 110.
One interesting item that I was unaware of is the starter does not care if it is 6v or 12v. It only runs faster on 12v. The tractor starts so much faster on 12v that there is actually less wear on the starter on 12v due to less run time. No need to change to a 12v starter.
The only problem I have had over the years is the carb. I did 3 overhauls before I wised up. I would up purchasing a new aftermarket carb and installed a large replaceable fuel filter in front of the carb. No problems at all for the last 12 years. I change the fuel filter every 200 hours now. The sediment bowl and inlet screen are just not adequate for the small internal passages in the up flow carbs.


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