8n and recurring ignition problems

[cumbres]

We just purchased a 8N. It has a 12 volt kit in it. When we got it it was wired so that the alternator ran the ignition and the battery the starter. We redid the wiring to fix that problem.

Now we find after running the tractor 10-20 hours that the engine starts to develope a "bark" sound to the exhaust and shortly after that we need to start using choke to make the engine have power and to keep the governor from hunting.

If we replace points/condensor the problem goes away. After replacement the tractor runs great.

I have double checked the wiring and had a second person do the same. I have verified that the dropping resistor is cutting the voltage to the coil to about 6 volts. When running the alternator puts out 13.5-14 volts. I have reviewed the 50 tips and almost anything else on ignition problems on this website. Nothing seems to help. The coil polarity appears to be correct.

I presume I am missing something. Can anyone of you help?

 

[dlplost]

points don't really care about volts, but any more than about 3-3.5 amps will burn them. Thats what it sounds like is happenng.
check the current thru the points when the points are closed. You may not have enough resistor in the line...

 

[cumbres]

That would make some sense as we have replaced the key switch too. Went bad very shortly after the rewiring. Also, when it was wired previously the alternator was only putting out about 3-4 volts when I measured it. Maybe that is why this was more reliable for the previous owner. Although, he stated he had had carb problems that were not resolved even with a brand new carb. We have not seen carb issues, just this issue. I will check the amps tonight.

Thanks!

 

[lha]

Get a clamp on ammeter[I have an A.Sperry],then you can clamp around the wire after passing through the resistor in lowest setting[mine has a 6amp max setting]and read the amps.Or you can use alligator clips,remove wire from resistor to coil,hook one clip to resistor,other to wire to coil.this will enable you to read amps with a regular analog[not digital]multimeter.---lha

 

[Dell (WA)]

cumbres.......the 12v alternator has ONLY 1-job, keep the 12v battery charged. The battery has 3-jobs, 1-turn the starter motor thru the solenoid; 2-run the sparkies thru the ignition switch; 3-lite the lites with the lite switch. All this goes-into and comes-outta is thru the AMP-meter terminals.

I'm gonna make a WAG (wild azz guess) that you have the 4-nipple frontmount dizzy with squarecan coil. No matter what the battery volts is, the squarecan coil need the MANDATORY "infamous ballast resistor". NO ARGUE!!! A 12v conversion ALSO NEEDS a 12-to-6v converting resistor. 2-resistors in series like flashlite batterys.

Iff'n you don't have 2-separate resistors, yer going to be MELTING yer squarecan coil and burning yer points, causing weak sparkies and "barking". Enriching (choke) yer carb mixture is a sign of weak sparkies.

Now go out and check yer wiring again. Report back. .......Dell, a 12v advocate for the right reason who knows 8-ways to convert to 12v and a gazillion ways that don't work

 

[cumbres]

I will be checking all the recommendations. Unfortunately my multimeter is digital and not analog.

Dell, I have the side mount round distributor with a round drop in coil. When I rewired I ran the alternator output to the amp meter and all of the loads plus the battery on the other lug on the amp meter. The dropping resistor (single and added by me) is in the circut where it comes off the amp meter but before it goes to the key and rest of the ignition system.

When I start the tractor the amp meter shows about a 20 amp charge for a short period of time after cranking and then it drops rapidly to neutral with no indicated charge or discharge.

One area that I did have confusion was when I put the alternator in the circut. Most wiring jobs I have done previously used a 1 wire alternator and this one I believe (have to check) has 3 (maybe 2, don't remember) wires.

Anyway you all have been a great help so far in confirming my belief that this is ignition and that I am probably having too much current through the ignition. I had presumed that if we dropped the voltage 6 the amps would be ok, probably a wrong assumption on my part.

Currently the tractor is running but the fellow who had it out yesterday told me that it started surging and having the barking sound after he had run the engine at flat out throttle while pulling a downed tree. It was a change that occurred over a very short period of time. Don't know if that is useful info but I found it curious.

Cumbres

 

[Dell (WA)]

cumbres.......ok, I flunked mind reading, just ask my ex-wife of 32yrs.

5-nipple dizzy with roundcan coil; 'sedda' 4-nipple.......right

On 12v conversions for 5-nipple dizzy, we always recommend the NAPA IC14SB coil ($15, cheap) and NO RESISTORS EVER. .......Dell, yer sparkie-meister

 

[cumbres]

So what is different about that coil that will stop my points and condensors from getting eaten??? Is there an internal resistor? I believe the coil that is in it is from Tractor Supply. No NAPA's in my town but there are some about 100 miles away.

 

[Dell (WA)]

cumbres......the NAPA IC14SB is designed for 12v application with NO RESISTOR, EVER!!!

There is NO specific internal resistor, just the coil windings themselves have enuff natural resistance for 12v to prevent the points from burning. Its designed that way. Condenser don't care, 6-or-12v, they're good for about 200v

There are alotta "12v-coils", that are NOT TRUE 12v coils and require an external resistor. Its an engineering trick to please the bean counters. Cheaper coil + cheaper resistor means more profit. ......Dell, sparkie-meister

 

[cumbres]

(quoted from post at 04:42:19 06/17/10) cumbres......the NAPA IC14SB is designed for 12v application with NO RESISTOR, EVER!!!


I looked farther back in the rescesses here and found that description a little bit ago too. Thanks for the update. Am trying to get someone to make a road trip to buy me one. HOpefully in a day or so.

Thanks guys!

 

[DollarBill]

[b:ed652aa060][color=darkred:ed652aa060]Am trying to get someone to make a road trip to buy me one.[/color:ed652aa060] [/b:ed652aa060]

NAPA sells parts online - Would save you a trip.

Postage would be a wash considering the cost of fuel for a 200 mile trip.

 

[cumbres]

Well we got the new coil and all ran well. But again after about 5-10 hours the engine started to run ragged as I discussed earlier. However we did find that taking the distributer cap off and cleaning the posts inside fixed the problem and off it ran well again. It does appear that the rotor and cap are scraping slightly. The rotor has a little bit of play in it too, ie it will move side to side slightly. Is there an easy fix? Most of the equipment I work on does not have distributers so this is new territory for me.

Thanks guys!

 

[DollarBill]

[b:bca8f21923][color=darkred:bca8f21923]The rotor has a little bit of play in it too, ie it will move side to side slightly. Is there an easy fix?[/color:bca8f21923][/b:bca8f21923]

When you say the rotor has play in it, are you referring to the clearance between the rotor and the distributor shaft or does the distributor shaft have side play in it?

If it's the rotor you're speaking of - You can bow the clip out to where it makes the rotor fit tighter.

If the dist shaft is loose, you will likely need a new shaft and bushings - Unless it's giving you driveability issues, I wouldn't fool with it due to the cost. If the shaft/bushings are loose, the advance weights are likely worn too. The weights, bushings and shaft will set you back $150.00 + shipping.

 

[cumbres]

(quoted from post at 15:10:23 06/26/10)

[b:5c95dc7d0f][color=darkred:5c95dc7d0f]The rotor has a little bit of play in it too, ie it will move side to side slightly. Is there an easy fix?[/color:5c95dc7d0f][/b:5c95dc7d0f]

When you say the rotor has play in it, are you referring to the clearance between the rotor and the distributor shaft or does the distributor shaft have side play in it?

There is some slight side to side movement of the distributor shaft. the rotor is tight on the shaft.

But, I had a chance to bring the tractor home to the shop. Stopped 3 times on me. Definitely electrical. As I was poking around I discovered that it appeared that the center black dot on the coil post of the distributor seemed "loose". When I pushed on it and put the distributor back on it would run for a short time.

When looking at the post there is a center black plastic part, like a ball, surrounded by a narrow metal ring. That center ball rotated and moved. Went to the Ford Toy Store (New Holland dealer) and bought a new distributor. It fit better then the old one. The old one was slightly bigger in diameter then where it attached. After verifying that the plug wires were on correctly and in the right order I fired it up and it ran better then earlier in the day and didn't stop on me when I took it back to its home.

So, guess I should have looked at the distributor earlier in the process.:idea:

Cumbres

 

[DollarBill]

[b:0c729c7958][color=darkred:0c729c7958]When looking at the post there is a center black plastic part, like a ball, surrounded by a narrow metal ring. That center ball rotated and moved. Went to the Ford Toy Store (New Holland dealer) and bought a new distributor. It fit better then the old one. The old one was slightly bigger in diameter then where it attached[/color:0c729c7958].[/b:0c729c7958]

Are you trying to tell us the distributor cap was faulty?

Glad you got it going!!

 

[cumbres]

It appears that way. But I have had it fixed 3 or 4 times now and it seems to find another way for the ignition to fail. Keeping fingers crossed.