Spark

stmar · May 12, 2017

8N 6volt started right up but after a few minutes it was sputtering, died, got it started again but ran rough and finally died for good. New points and they are gaped right, put another set of plugs in, old ones were kind of fouled but nothing out of the ordinary. Tested for spark and nothing. Any ideas where to start looking? I have another 8N that I can take parts from to test before I go and buy something I don't need.

Bruce (VA) · May 12, 2017

Front or side distributor?

Do you have battery voltage at the coil w/ the points open & about half that when closed?
75 Tips

Dell (WA) · May 12, 2017

stmar........hows yer ears? Still wet behind them? 1st thing to check, gott enuff gasoline??? Yeah, ittza 10-gal tank that you donna wanna use the last 1-gal which has crud and WATER inn itt. Yer description of starts rite up, sez gas is probably OK. ...but... the few minutes time frame is typical of BAD condenser. BOTH use the same condenser. While some of the early 8N's have that weird 4-nipple frontmount (points = 0.015) and the more normal 5-nipple sidemount (points = 0.025) BOTH use the same sparkies, recommend AutoLite 437's gapped 0.025. Keep yer itchy-twitchy fingers off'n them handy-dandy carbie tweek-ums. They aintchur problem. Iff'n ya done futtzed with'em, fess-up and I tell you how to adjust'em rite.......HTH, Dell, yer self-appointed sparkie-meister

Tim PloughNman Daley RIP · May 12, 2017

I agree it sounds more like a fuel issue than electrical. How did you 'test for spark'? Dry out a set of 437's, wire brush them a bit, recheck gap. Take and old plug, pry the electrode open ay least 3/16", more if possible and use that for your test plug. Check your fuel line/sediment bowl for fuel flow. With engine COLD -first, check that you have at least a half tank of gas in the fuel tank. Next, Remove fuel line at the carb brass inlet elbow, point downwards into a coffee can, and open sediment bowl valve 2 turns. Fuel should flow at a nice, pencil thick, steady stream, without any hesitation or stopping and starting. If it does, you have plugged screens in the sediment bowl assembly. The third screen is in the brass fuel inlet. You can also wash and clean the debris out of that as well. Be sure you shut the sediment bowl fuel valve OFF every time you shut tractor down. Start there then we'll proceed to the electrics if needed...

SEDIMENT BOWL & FUEL FILTERS; (photo courtesy of Bruce Haynes):

Tim *PloughNman* Daley(MI)

teddy52food · May 12, 2017

Did you clean the new points?

Tall T · May 12, 2017

Stmar,

First thing I do under "no firing" situations is to check for spark at the points.

You said you tested for spark, but it sounds like you meant at the plugs.

Roll the engine via the fan, until the points close.
Turn the key on and open the points with a small screwdriver or something. If you get a spark . . . you have spark at the points.
If not go backwards from there.

Don't forget and leave the key on.

stmar · May 12, 2017

Got it started, replaced the new points but I am thinking it may be a fuel problem as posters noted. Reason I agree with them is that it is running rougher than normal so I will go through the fuel system and carb to see what I can find, probably needs a good cleaning anyway. Thanks for the input, I have no explanation why I did not see a spark unless it was a multi level problem. Good thing about these machines is that you can work on them.

stmar · May 12, 2017

Did not clean the new points when I put them in a few weeks ago but had no problems until now. Good tip, thanks.

Dell (WA) · May 12, 2017

stmar........didja read that I'd help you with yer carbie. Given yer stellar performance with yer sparkies, you are a GLUTTON fer punishment........respectfully, Dell, yer self-appointed sparkie-meister and mind reader

stmar · May 13, 2017

Thanks Dell, I will change out condenser and see if that does the trick.

stmar · May 14, 2017

I bow to the master. It was a new condenser but obviously that is not a sure bet in this day and age. I put the old condenser back in, I replaced it only because I bought a kit and it had a new one in it. So far it is running normally. Thanks Dell, you saved me a few hours of running in circles again. You truly are the 8N Master.

stmar · May 14, 2017

Dell does it again.

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