timing problem?

sam in nc · Jun 27, 2015

I just rebuilt the engine on my front mount distributor 8N and can't get it to start. Seems like it wants to fire, but doesn't quite. I haven't had any back firing. I'm wondering if I got the cam shaft gear timing off by a tooth.

Any thoughts or help would be greatly appreciated?

JMOR · Jun 27, 2015

(quoted from post at 12:17:03 06/27/15) I just rebuilt the engine on my front mount distributor 8N and can't get it to start. Seems like it wants to fire, but doesn't quite. I haven't had any back firing. I'm wondering if I got the cam shaft gear timing off by a tooth.

Any thoughts or help would be greatly appreciated?

efore I started second guessing myself on that, I would try starting fluid and pull starting in 4th. Sometimes a 6v system just has a hard time with a new tight engine in getting both spin and strong ignition.

sam in nc · Jun 27, 2015

Thanks, I've tried starting fluid and didn't get any different response. It is a 12 V system.

JMOR · Jun 27, 2015

(quoted from post at 13:03:26 06/27/15) Thanks, I've tried starting fluid and didn't get any different response. It is a 12 V system.

ow is the spark? Temporarily jumper the resistor in ign circuit.

sam in nc · Jun 27, 2015

Spark appears strong. The conversion to 12 V alternator was completed when I bought the tractor several years ago so I went ahead and converted to an electronic ignition (12 V negative ground) while doing this rebuild.

This could also be the problem and I can switch back to the points to trouble shoot.

sam in nc · Jun 27, 2015

Starter was just rebuilt and new battery installed as well.

JMOR · Jun 27, 2015

(quoted from post at 13:32:59 06/27/15) Spark appears strong. The conversion to 12 V alternator was completed when I bought the tractor several years ago so I went ahead and converted to an electronic ignition (12 V negative ground) while doing this rebuild.

This could also be the problem and I can switch back to the points to trouble shoot.

hat coil & resistors did you use in the conversion?

sam in nc · Jun 27, 2015

I bought a kit and followed instructions with kit. The coil is round and I'm not sure about the resistor.

sam in nc · Jun 27, 2015

It is a Pertronix kit purchased through Yesterday's Tractor (PN 1247XT)

JMOR · Jun 27, 2015

(quoted from post at 14:05:16 06/27/15) It is a Pertronix kit purchased through Yesterday's Tractor (PN 1247XT)

he Pertronix instruction sheet that I have shows no resistor. Did your kit come with a resistor? Did your coil come as part of the kit or purchased separately? Does coil have a part number?

sam in nc · Jun 27, 2015

I don't see a part number for the coil - I'll go out and look to see if there is one on it. I also don't recall a resistor. Here is a link to the kit picture (http://pertronix.carshopinc.com/product_info.php/products_id/88932/1247XT).

Dell (WA) · Jun 27, 2015

Sam.........heres the deal, Pertronix doesn't like 6-volts. The original 6-volt positive ground 4-nipple dizzy with square can ignition coil used the infamous BALLAST resistor to cut the 6-volts down to 3-volts. Iff'n yer poorly written Pertronix instructions didn't tell you to remove the ballast resistor, then yer 12-volt round coil is runnin' on 6-volts and guess what??? WEAK SPARKIES!!! The infamous ballast resistor is mounted on the BACK side of the dash underneath yer AMP meter gauge. It is usually a WHITE ceramic device with sheet metal protective cover. CAUTION: ballast resistor gitts HOT!!!! burnie-burnie ........Dell yer self-appointed sparkie-meister and 12-volt advocate for the right reason

sam in nc · Jun 27, 2015

I don't see a part number on the coil.

JMOR · Jun 27, 2015

(quoted from post at 15:13:14 06/27/15) I don't see a part number for the coil - I'll go out and look to see if there is one on it. I also don't recall a resistor. Here is a link to the kit picture (http://pertronix.carshopinc.com/product_info.php/products_id/88932/1247XT).

K, no resistor & coil was part of kit, so for now we will assume that it is correct coil and move away from spark. Can you do a compression test?

Skeeter102 · Jun 27, 2015

I converted my 8n to 12v and used a pertronix kit. When I first installed the kit, I had spark but could not get the tractor to run. My issue was with the plate that comes in the kit that bolts down inside the distributor. It has a clockwise hole and a counterclockwise hole. Make sure you are using the correct one. I THINK its ccw but I don't remember offhand. When I installed mine, I initially used the wrong set of holes. Once I corrected it, the tractor ran like a champ.

EDIT. I just read that you had a front mount dizzy. Mine was a side mount, so what I just posted is more than likely irrelevant. Sorry. Long shift at work.

sam in nc · Jun 27, 2015

Thanks, Is this resistor different than the one that was on the wire between the ignition switch and the coil? I assume this resistor block was installed when the tractor was originally converted from 6 to 12 V.

Thanks,

sam in nc · Jun 27, 2015

(quoted from post at 12:25:36 06/27/15)

(quoted from post at 15:13:14 06/27/15) I don't see a part number for the coil - I'll go out and look to see if there is one on it. I also don't recall a resistor. Here is a link to the kit picture (http://pertronix.carshopinc.com/product_info.php/products_id/88932/1247XT).

Click to expand...

K, no resistor & coil was part of kit, so for now we will assume that it is correct coil and move away from spark. Can you do a compression test?

I don't have a compression gauge. I just rebuilt the engine and am fairly confident that compression is good.

sam in nc · Jun 27, 2015

(quoted from post at 12:25:36 06/27/15)

(quoted from post at 15:13:14 06/27/15) I don't see a part number for the coil - I'll go out and look to see if there is one on it. I also don't recall a resistor. Here is a link to the kit picture (http://pertronix.carshopinc.com/product_info.php/products_id/88932/1247XT).

Click to expand...

K, no resistor & coil was part of kit, so for now we will assume that it is correct coil and move away from spark. Can you do a compression test?

I don't have a compression gauge. I just rebuilt the engine and am fairly confident that compression is good.

sam in nc · Jun 27, 2015

Thanks Skeeter

JMOR · Jun 27, 2015

(quoted from post at 19:31:01 06/27/15) Thanks, Is this resistor different than the one that was on the wire between the ignition switch and the coil? I assume this resistor block was installed when the tractor was originally converted from 6 to 12 V.

Thanks,

his one is a factory resistor for all front mount distributor tractors. Pertronix does not want it in the wire feeding their module, so connect the wire feeding the module on the input side of resistor (ign sw side), not the normal output side.

Hobo,NC · Jun 27, 2015

(quoted from post at 05:33:26 06/28/15)

(quoted from post at 12:25:36 06/27/15)

(quoted from post at 15:13:14 06/27/15) I don't see a part number for the coil - I'll go out and look to see if there is one on it. I also don't recall a resistor. Here is a link to the kit picture (http://pertronix.carshopinc.com/product_info.php/products_id/88932/1247XT).

Click to expand...

K, no resistor & coil was part of kit, so for now we will assume that it is correct coil and move away from spark. Can you do a compression test?

Click to expand...

I don't have a compression gauge. I just rebuilt the engine and am fairly confident that compression is good.

I'm wondering if I got the cam shaft gear timing off by a tooth.

A compression test would be a good place to eliminate yer wondering confident are not...

sam in nc · Jun 27, 2015

OK - what would the compression reading be if cam shaft is timed correctly vs. being off by one tooth?

sam in nc · Jun 27, 2015

Thanks for the picture. I'm pretty sure this has been removed I installed a new wire directly from the ignition switch to the coil.

sam in nc · Jun 27, 2015

two of you have now suggested compression testing. I was thinking that being one tooth off on the cam wouldn't impact compression. Maybe a bad assumption on my part. I'll get a compression gauge tomorrow. What compression readings should I expect? Thanks

NOXJohn · Jun 28, 2015

Check to make sure you have the plug wires in the correct holes. I have had a front mount 8N for 45+ years and still screw up the plug wires on occasion.

sam in nc · Jun 28, 2015

Checked that earlier and figured out I had 3 and 4 crossed - was very hopeful that would solve the problem. Imagine my disappointment when it didn't.

Thanks

JMOR · Jun 28, 2015

(quoted from post at 09:19:54 06/28/15) Checked that earlier and figured out I had 3 and 4 crossed - was very hopeful that would solve the problem. Imagine my disappointment when it didn't.

Thanks

am, I'm going to go out on a limb here & bet a dollar to a donut that your cam to crank timing is OK. Why? Because when you installed those gears, your focus was on those two gear marks & I just don't see missing this by a tooth.

Hobo,NC · Jun 28, 2015

With a few basic test you can eliminate our best guess...

1) confirm compression (not having a tester is not a excuse)

2) confirm spark with a spark tester (not having a spark tester is not a excuse as is your best guess is not verifiable either)

3) confirm fuel quality (it should always be confirmed on a no start/driveability issue) (( Well I guess you did with starting fluid)) Ditch the starting fluid and use brake clean..

1,2,3 are all basic test and as far as I know works on about any engine.

For anyone that goes into a front mount N engine once TDC has been located put a index mark on the crank pulley with some way to align TDC to the crank pulley... All this fiddle fart'N around with a points timing jig is for the birds its even worse trying to time EI...

JMOR · Jun 28, 2015

(quoted from post at 13:33:27 06/28/15) With a few basic test you can eliminate our best guess...

1) confirm compression (not having a tester is not a excuse)

2) confirm spark with a spark tester (not having a spark tester is not a excuse as is your best guess is not verifiable either)

3) confirm fuel quality (it should always be confirmed on a no start/driveability issue) (( Well I guess you did with starting fluid)) Ditch the starting fluid and use brake clean..

1,2,3 are all basic test and as far as I know works on about any engine.

For anyone that goes into a front mount N engine once TDC has been located put a index mark on the crank pulley with some way to align TDC to the crank pulley... All this fiddle fart'N around with a points timing jig is for the birds its even worse trying to time EI...

gree with all of it! Especially that last timing paragraph! I do love propane though over starting fluids.

NoNewParts · Jun 29, 2015

(quoted from post at 14:44:27 06/28/15)

(quoted from post at 13:33:27 06/28/15) With a few basic test you can eliminate our best guess...

1) confirm compression (not having a tester is not a excuse)

2) confirm spark with a spark tester (not having a spark tester is not a excuse as is your best guess is not verifiable either)

3) confirm fuel quality (it should always be confirmed on a no start/driveability issue) (( Well I guess you did with starting fluid)) Ditch the starting fluid and use brake clean..

1,2,3 are all basic test and as far as I know works on about any engine.

For anyone that goes into a front mount N engine once TDC has been located put a index mark on the crank pulley with some way to align TDC to the crank pulley... All this fiddle fart'N around with a points timing jig is for the birds its even worse trying to time EI...

Click to expand...

gree with all of it! Especially that last timing paragraph! I do love propane though over starting fluids.

LOL, plus 3 on making your own timing marks.
I think it must have been a joke among designers....
no marks, double marks, marks window underneath or on
the wrong side of the tractor...
make yer own where you want em.
Besides, gotta have a mark you can point a light at.
Initial timing is good but how will you know if the advance is working properly without a mark?

for the poster..fresh rebuilds are tight and have assembly oils flying everywhere..only spark that counts is the hot one at the end of the installed plug in the hole.(not uncommon if you 'miss' it on the first start to have assembly oils put the fire out)
Valve timing? go thru the lash adjust/check procedure again like you did after assembling the engine. All look good?

timing problem?

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