8n timing question

cbradio

Member
Hi,

8n 12v side distro.

When timing with a light, it tends to bounce +- 2 deg and never maintains a specific degree setting. What could be causing this? I took the governor apart and cleaned and inspected but did not find anything obviously wrong with it. Something in the distributor?

Thanks,

Cam
 
(quoted from post at 05:40:12 07/25/14) Hi,

8n 12v side distro.

When timing with a light, it tends to bounce +- 2 deg and never maintains a specific degree setting. What could be causing this? I took the governor apart and cleaned and inspected but did not find anything obviously wrong with it. Something in the distributor?

Thanks,

Cam

Not enough info. What's it doing while you are timing it as far as RPM's? Steady, slowing increase/decrease while turning the distributer, surging?

If it's steady I'd check the distributer or in/decrease again the dizzy. If it's surging figure out what's wrong and go from there.

Rick
 
The governor has nothing to do w/ timing. But I'm sure the cleaning was helpful.

" it tends to bounce +- 2 deg and never maintains a specific degree setting. "

At what RPM?

There are three settings.

At idle, the light should flash & the marker should line up exactly at 4* if you did the static timing correctly.

If not, loosen the distributor & turn it until the marks line up. It should take very little adjustment.

Once you've got that done, increase the engine speed to 1200 rpms. The light should flash & the marker should line up w/ the 10* mark. Then, increase the rpms to 2000 & look for the marker to align w/ the 17* mark.

Close counts on the advanced timing. A degree or 2 either way is ok. But, no movement or 5* or more off means you have an advance weight problem. You don't adjust the distributor to fix that.
 
(reply to post at 09:55:54 07/25/14)

I was having a clogged carb issue due to grit from new gas tank but it did this before I changes tank and after I cleaned the carb. I am currently installing new water pump and radiator,so I won't be able to check again until that is complete
 
(quoted from post at 08:40:12 07/25/14) Hi,

8n 12v side distro.

When timing with a light, it tends to bounce +- 2 deg and never maintains a specific degree setting. What could be causing this? I took the governor apart and cleaned and inspected but did not find anything obviously wrong with it. Something in the distributor?

Thanks,

Cam
call that acceptable. Most especially in the rpm range that it is not at zero or not maximum full centrifugal advance, i.e., in the mid range. Generally steady more at the limits.
 
Adjust igniting timing at 400 engine RPM.

If timing is irratic look to centrifugal spark advance mechanism and/or distributor bushings.

Dean
 
(quoted from post at 11:52:21 07/25/14) Adjust igniting timing at 400 engine RPM.

If timing is irratic look to centrifugal spark advance mechanism and/or distributor bushings.

Dean

I wasnt able to fins bushings for the side mount distro in YT. Do they still exist?
 
Side-mount bushing is #8N12120.

If you GOOGLE "Ford 8N12120" or "CNH 8N12120" you will find lots of sources.

(They are just under $50.00 at the FIAT stealership!)
 
If you are using a inductive timing light (clamp on pick up) they go crazy on solid core wires and non resistor plugs... All you can hope to do is guesstamate it close... Total it out at 20 and move on with life...
 
I agree with hobo here, you will probably not get a steady reading. I had to replace my distributor, so even with a new one the needle still bounced around. Mine bounced in all ranges but seemed to be a little smoother above 1200 RPM or so.

On a side note I question if 4* really matters or if it would help to advance them more considering when these tractors came out the fuel quality was much lower than modern fuel and octane ratings were in 70's. Not that higher octane is needed with these low compression/low output engines.

With modern higher quality fuel with octane ratings around 10+ points higher than what these engines were designed for, would these engines benefit with more advance to compensate the higher octane fuel?
 
do you have a good quality point set?
guys have the bushings covered.
all old tractors need the distributor taken apart and the advance mechanism cleaned and inspected. rust. and check that the weight pins/slots aren't hogged out from wear.

With that done, as said, set the total at the books specified rpm and yer good. I check it at idle too, but the total is more important as that is where the tractor runs when working.
Manuals are written by new tractor people whose bearings and oil pump are much better than mine! The only time my tractors are at that super low idle is...almost never. A little over idle for cooldown, then lowest idle for a second and turn the key off.

The other question, well you could 'hotrod' it like the old days, advancing a little and listening for ping under load....
but
working on off brands with difficult timing marks, getting them running, before I have marked the pulley.
Advancing/retarding, listening carefully for engine 'distress'.
get it where I want it, pull in the shop and check it with the light.
very close to book specs.
In this case, the engineers knew what they were doing. Go by their specs.
 

I could be wrong but I disagree.
An old man who owned our shell station in the 70's told me one day:

"Fuel has deteriorated to the degree that to get the octane value that good old regular used to have, you have to use today's Hi-test."

In other words, the olden day fuel was better than today's.

He had tractors and a sheep farm as well.
His name was Ron Lee and when driving down our steepest hill, Lee's Hill (named after him) , I used to see him on his tractor.

The view of the Fulford Valley from his farm.
mvphoto9548.jpg
 

It don't it just makes you look smarter (book smart) to advertise it... Working around the book is something you learn its not in a book... I don't condemn the book are the preachers that preach it you gotta start somewhere... Base timing is just a starting point from there it means nuttin...

To me its just like setting points they are only in spec one time the time you install a fresh set... I set points a tho are so on the high side and the timing the same way I wont it to come to me and not run from me... I have watched guys fudge with points to get them dead nutz with a feeler gauge if you do get them dead nutz you are lucky... You will come closer stepping up one tho on the feeler and shooting for slite to no drag... The only dead nutz way I know to to set them is with a dwell meter... If you could see dwell on a scope for every cylinder normally you will see one dead nutz a couple under and one a little over (just a example).. I would bring the 2 under up to dead nuts plus 1 and not worry about the others they will come to me in time... You could average the timing by reading #1 and # 3 if its a issue with ya... Lets say #1 is 2 deg and #3 is 6 deg.... 2+6 = 8... 8 divided by 2 = 4 deg... You have a average of 4 deg. leaving #1 at 2 deg would be OK in my book...

I just beat the drum on points WHY the point gap affects timing... issues that affect it have been covered...

Setting the timing has been discussed its in the book... I don't have to idle the engine down to a low point to adjust the base its not a issue to me. A few things it does prove, if you can idle it down that far your probably have a engine that's sealed well and a carb that's in good condition and adjustable..

The last thing you do while performing a tune up is adjust the carb... The reason being all adjustments affect the carb but the carb adjustment dose not affect the other adjustments...

If at times you need to tweak yer carb that should light a bulb off in yer head to check other adjustments are sealing issues...
 

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