8N10000 generator 8N10505 A or B regulator?

[BillSr]

This message is a reply to an archived post by JMOR on November 19, 2022 at 15:53:13.
The original subject was Re: 8N10000 generator 8N10505 A or B regulator?.

Maybe somebody can help me, I am getting desperate. I just got my 1948 8N after five years of off and on working on overhauling/restoring it had a three brush generator that I
converted to a two brush per Service Bulletin 78. I installed an 8N10505B voltage regulator according to the great information I have found on this forum. I wasn't sure, but I
used the wiring diagram on page 48 of the FO-4 for the 8N prior to serial number 263844. This 8N is has a front mount distributor by the way. When I got the tractor running it
didn't seem to be running real smooth. I made some adjustments to the carburetor, but they didn't seem to have much effect. I even bought a new carburetor and there wasn't any
difference. Also, when you increase the throttle, it starts to break down. The more you increase it, the more it breaks down. I made sure the carburetor floats were adjusted
right, nothing seemed to change. I looked at the plugs and it looks like it is running very rich. I also bought another distributor. It didn't make any difference and I did
check the points gap. I am thinking it is an electrical problem I have an extra coil which I swapped and no difference. It's almost like the spark is week and when you rev it
up it is too week and runs worst the higher you increase the RPM's. One question I have is, when you convert the generator from to two brushes, as far as I can tell, aside from
there being a different coil and distributor, you have the same components as in the diagram on page 49 of the FO-4 Should I be wiring it to this diagram and not the one for the
early serial numbers? If I didn't mention it above, I did check the spark of each plug and they were all arching. By using the new regulator 8N10505B and the early serial number
circuitry, is that, along with the ignition resistor, weaking the spark? I don't understand enough about electronics to know what the possibilities are. But I still would like to
know why in the later circuit the battery voltage goes directly to the coil while in the earlier circuit it goes through a resistor. Does the later coil have a built in resistor?
One other thing I need to mention is that, over a several day period, after having put my old distributor back in, it seemed to run fine for several starts and one time down the
road, but then went right back to the way it was. Crazy! Could this be attributable to an intermittent short somewhere, but I still wonder about what circuitry I should be
using. Thanks for any suggestions anyone can give. I don't know what else to try.

 

[JMOR]

(quoted from post at 12:07:06 06/16/23) This message is a reply to an archived post by JMOR on November 19, 2022 at 15:53:13.
The original subject was Re: 8N10000 generator 8N10505 A or B regulator?.

Maybe somebody can help me, I am getting desperate. I just got my 1948 8N after five years of off and on working on overhauling/restoring it had a three brush generator that I
converted to a two brush per Service Bulletin 78. I installed an 8N10505B voltage regulator according to the great information I have found on this forum. I wasn't sure, but I
used the wiring diagram on page 48 of the FO-4 for the 8N prior to serial number 263844. This 8N is has a front mount distributor by the way. When I got the tractor running it
didn't seem to be running real smooth. I made some adjustments to the carburetor, but they didn't seem to have much effect. I even bought a new carburetor and there wasn't any
difference. Also, when you increase the throttle, it starts to break down. The more you increase it, the more it breaks down. I made sure the carburetor floats were adjusted
right, nothing seemed to change. I looked at the plugs and it looks like it is running very rich. I also bought another distributor. It didn't make any difference and I did
check the points gap. I am thinking it is an electrical problem I have an extra coil which I swapped and no difference. It's almost like the spark is week and when you rev it
up it is too week and runs worst the higher you increase the RPM's. One question I have is, when you convert the generator from to two brushes, as far as I can tell, aside from
there being a different coil and distributor, you have the same components as in the diagram on page 49 of the FO-4 Should I be wiring it to this diagram and not the one for the
early serial numbers? If I didn't mention it above, I did check the spark of each plug and they were all arching. By using the new regulator 8N10505B and the early serial number
circuitry, is that, along with the ignition resistor, weaking the spark? I don't understand enough about electronics to know what the possibilities are. But I still would like to
know why in the later circuit the battery voltage goes directly to the coil while in the earlier circuit it goes through a resistor. Does the later coil have a built in resistor?
One other thing I need to mention is that, over a several day period, after having put my old distributor back in, it seemed to run fine for several starts and one time down the
road, but then went right back to the way it was. Crazy! Could this be attributable to an intermittent short somewhere, but I still wonder about what circuitry I should be
using. Thanks for any suggestions anyone can give. I don't know what else to try.

he old square plastic coils have a very low resistance primary and without the resistor to limit current to a safe level, they would soon be toast, whereas the later round can coil has ~2X the resistance which means that it self-limits current, thus no resistor needed. As for rich mixture turn the main adjust screw in about 1/4 turn and try running, then another 1/4, etc. Each step leans the power mixture. Idle mix is just the opposite, IN to make richer.

 

[Tim PloughNman Daley RIP]

HiYa Bill-
Well documented trouble shooting Bill, and I agree you have an electrical issue, not fuel. You could do the Fuel Flow Test with the engine cold to verify and if it passes, leave it alone. If you followed the sketch in the FO-4 Manual you would be correct for 8N from 47-50 with front mount distributor. I don't think switching a 3-BRUSH GEN to a 2-BRUSH GEN per the Service Bulletin shown is the root cause problem, but you could have a shop verify it to be sure. Converting 3 to 2 brushes has nothin to do with VR. You have the right VR, with the 8N-10505-C unit designed for the later 8N GEN with 20 AMP output and would work on the early GENS too. Early 8N GENS were 11.5 AMPS. Did you polarize GEN? I don't suspect that is the root cause either but just covering all the bases in case. If you have the OEM Ballast Resistor in the circuit wired correctly, the 3-Wire GEN wired correctly- BE SURE YOU HAVE THE BELT TENSIONING ARM SET, 3-Wire VR wired correctly, the 3-Wire Starter Motor & Relay wired correctly then you are half way there. Can do a basic coil test static. Set coil to OHMS, top post terminal on one probe, the other probe on bottom pigtail curly-Q. Reading should be 1.5 OHMS for a 6V coil, double that for a 12V coil. NOW, the bad news. The front mount distributor is the 2nd most misunderstood feature on these FORDS. The 6-VOLT/POSITIVE GROUND system is the first. This coil test is not 100% foolproof, and it could be bad and will malfunction if it is when it gets hot. Ever leave key ON? If so and points were closed, would burn up points and cause coil to melt tar insulation internally. Next, and most importantly is the distributor. We know it must be tuned up on the bench with point gap set correctly at .015, tested static with your VOM set to continuity, then, and this is the trick, mounted on engine correctly. The engine Camshaft Head has an offset female slot on it and the Distributor Cam & Weights have an offset Male Tang on it and the two parts MUST mate exactly when mounted. If they get forced down 180 DEG off, at first power they will try to orientate themselves and end up busting the aluminum base on the unit thus render the base junk. The guts are still good, can be pulled and reset in a new base. The trick is to get the rotor aligned with the tang on distributor with the camshaft head. Takes patience and several close inspections when doing mounting to ensure unit is flush to engine face. Needed are a good flashlight and a telescoping inspection mirror and lots of patience. Next, when satisfied unit is mounted correctly and before powering up, do a quick coil test to distributor. Set VOM to VDC. Measure battery static and note reading. Then set Probe #1 to LH Ballast Resistor as viewed from behind dash - this is the coil wire connection, and Probe #2 to any metal ground. Polarity doesn't matter for this test. Place IGN KEY to ON but do not turn key to start position. VOM should read battery voltage with points open, half that with points closed. So far good? Move on but now place Probe #1 to top of coil terminal post. Repeat. Should get same results. If OK, you are getting power to your distributor. If not, problem is in distributor. If all is good can now attempt to turn over engine. FWIW: Points are .015 on front mount; plug gap is .025 - 028, and firing order is 1, 2, 4, 3 CCW. Be aware that there now only but a few brands of points that are good anymore. Most cheap Cheena made ones are junk and can't be gapped and aligned correctly. The ECHLIN CS-35 Brand used to be one of the good ones with the OEM Phenolic Rubbing Block so avoid them. The best ones are: STANDARD IGNITION/BLUE STREAK FD-6769X and aso use the OEM phenolic rubbing block; the TISCO ATK6FF kit includes the condenser and a .015 feeler gage; and the CNH p/n 87744524 with the latter two with a plastic rubbing block but have a proven track record. Have tested a few cheap chi-comm made with no success. Hade a guy tell me he bought a set from TSC, County Line(?) and he had no problem after and tractor ran good and strong he said. The major issue is once unit is tuned an tested, mounting correctly becomes the focus. See if these points ( pun intended) help you and get back. I have a few OEM rebuilt distributors all set and ready to go and can rebuild yours if requested. My email is open.


ORIGINAL 8N WIRING, BEFORE S/N 263844:

*NOTE: FIRING ORDER IS SHOWN WRONG - SHOULD BE 1, 2, 4, 3 CCW.

FRONT MOUNT TIMING PROCEDURE:

ORIGINAL FORD SERVICE BULLETINS - 8N GENERATOR:

I&T FO-4 SERVICE MANUAL, 8N WIRING BEFORE S/N 263844:

8N WIRING DIAGRAMS; FRONT MOUNT & SIDE MOUNT; 6V/POS GRN:

BALLAST RESISTOR USED ON FRONT MOUNT ONLY:

FRONT MOUNT OFFSET CAM HEAD AND DISTRIBUTOR CAMM & WEIGHTS:

WHAT HAPPENS WHEN DISTRIBTOR IS MOUNTED 180 DEG OFF ALIGNMENT:

8N GEN BELT TENSIONG ARM, EARLY FRONT MOUNT, BEFORE S/N 263844:

POLARIZING GEN VIA VR:

FRONT MOUNT DISTRIBRITOR 6V COIL TEST:

N-SERIES FIRING ORDER:

Tim Daley (MI)

 

[BillSr]

I hope everyone who read my first post about my 8N breaking down sees this post. Thank you Tim PloughNman and JMOR for quick response and great advise. I just found out what the
problem was. For me, this situation is both embarrassing and humbling and I want to apologize to you guys and anyone else who spent their time reading my post. The day the tractor
briefly ran good, my friend was helping me work on it. He also has an 8N. Each time we started it and then stopped it, we would turn the gas off. My son learned that lesson the hard
way once. On my uncle's farm I always turned the gas off and when I turned it on I gave it about 1/2 turn. I never had a problem that I remember. I noticed my friend when we were
working on it, he would always turn it on a few turns. While I was working on it I had the hood off and was using a small lawn mower gas tank suspended over it. After I put the hood
back on it I dumped a small amount of gas in the tank. Apparently, after that, before I drove it down the street and it ran well, my friend must have turned the gas on for me and when
I got back one of us turned it off. After this he took it down the street and I must have turned the gas on this time (half turn). After a few seconds when he took off it started
running bad again. Last night I read in one of the repair manuals about the gas tank reserve and number of turns, which I never knew about. I've always been used to the reserve on a
motorcycle. Something clicked in my head and today I put more gas in it and turned the valve more and now it runs fine. Again, I apologize and feel pretty stupid about it. Thanks
again guys for your help. Bill

 

[Tim PloughNman Daley RIP]

Just to be clear Bill, The OEM 8N-10505-A VR was the original AUTO-LITE unit, NLA, but you can find NOS ones on ebay. The 8N-10000-B VR is the one used on early 8N's, s/n prior to 263844 with front mount distributor. The 8N-10505-C VR is the one after s/n 263844 for side mount distributors and with the larger 20-AMP GENERATOR.

8N-10505-A VOLTAGE REGULATOR, p/n VRR-4008:

AFTERMARKET AUTO-LITE VRR REPOP, GUARANTEED PRODUCTS ON LEFT, OEM ON RIGHT:

Tim Daley (MI)

 

[BillSr]

Thanks a lot JMOR

 

[Eman85]

"I looked at the plugs and it looks like it is running very rich"
That goes against the running out of gas fix.

 

[JMOR]

(quoted from post at 12:52:43 06/18/23) "I looked at the plugs and it looks like it is running very rich"
That goes against the running out of gas fix.

ell, ....he did say, "looks like"!?

 

[BillSr]

Ok, I found out today when I ran the tractor over to a friends house that the problem still exists. It was running fine at first and every other time I had started it up with the gas
idea. I think my idea that it was running out of gas was wishful thinking. It sort of didn't make sense, but the reserve thing with the gas valve, which I still don't fully
understand, kind of gave me an excuse, at least in my mind, to think that way. Looking back on its behavior it seems to get worse as the engine heats up and I guess I hadn't run it
enough to heat it up until going to my friend's house. This makes me think it might be the coil as Tim suggested. I haven't had time to do any of the tests that Tim gave me to try,
but I am going to try to find time on Monday. I have been swapping parts here and there. I have two coils and two different distributors. I haven't documented which combinations I
have tried, which is what I am going to start doing. I'm pretty sure I tried either coil, but not sure. Along with the tests Tim suggested, I will swap the coils while keeping the
distributor that's in there now and see if that makes a difference. I am also going to buy a good set of points. With the points I have in my old distributor now, when I adjust them,
the screw that the squiggly thing on the bottom of the coil makes contact with, ends up in a position considerably to one side and not centered very well directly under the squiggly
contact so I have to really take care that the tip gets in the center of the screw. I am thinking that a different set of points might help correct that situation. I will get back
with the results of my testing and getting a new coil. Tim, can you recommend a source for a good coil? Thanks again for everybody's help.

 

[JMOR]

(quoted from post at 00:59:02 06/19/23) Ok, I found out today when I ran the tractor over to a friends house that the problem still exists. It was running fine at first and every other time I had started it up with the gas
idea. I think my idea that it was running out of gas was wishful thinking. It sort of didn't make sense, but the reserve thing with the gas valve, which I still don't fully
understand, kind of gave me an excuse, at least in my mind, to think that way. Looking back on its behavior it seems to get worse as the engine heats up and I guess I hadn't run it
enough to heat it up until going to my friend's house. This makes me think it might be the coil as Tim suggested. I haven't had time to do any of the tests that Tim gave me to try,
but I am going to try to find time on Monday. I have been swapping parts here and there. I have two coils and two different distributors. I haven't documented which combinations I
have tried, which is what I am going to start doing. I'm pretty sure I tried either coil, but not sure. Along with the tests Tim suggested, I will swap the coils while keeping the
distributor that's in there now and see if that makes a difference. I am also going to buy a good set of points. With the points I have in my old distributor now, when I adjust them,
the screw that the squiggly thing on the bottom of the coil makes contact with, ends up in a position considerably to one side and not centered very well directly under the squiggly
contact so I have to really take care that the tip gets in the center of the screw. I am thinking that a different set of points might help correct that situation. I will get back
with the results of my testing and getting a new coil. Tim, can you recommend a source for a good coil? Thanks again for everybody's help.

he timing adjustment is what changes the position of the screw that the "squiggly thing" seats in.

 

[BillSr]

I want to thank everybody who responded to me about my 8N breaking down when increasing the throttle. As you guys thought from the beginning, it was electrical and it was the coil. Bought another coil, put it on and it started right up and is running fine. Thank you again, this has been a real thorn in my side.