New guy with a free 8n, carb part missing, questions

dogsled1

Member
So I was given an 8n that last ran about 3 years ago or so I'm told. It is in pretty rough shape overall, especially the sheet metal Has been outside most of its life as near as I can tell. It is a 1952 with side mount distributor.

I have been doing quite a bit of reading on the model and have done some work to it. Someone had started the conversion to 12V, I found some writeups on line and finished that up this weekend.

I checked the compression, all 4 cyls have about 115 PSI. It sparks and will try to run if you shoot some starter fluid to it. I took the carb off and cleaned it out, I think it will need to be rebuilt, but while I had it off I dropped the small drain plug from the bottom of the carb. It had a through hole and looked like a jet to me. The hole was clogged so I removed it to clean it out and lost it in the grass. The location of the part is the bottom right hand image on the 8n carb rebuild page on this site. I tried to embed a link, but that isn't allowed for new guys apparently.

Can somebody tell me where I can get one of these plugs? Do they come in the rebuild kits? A part number would be great!

When we were turning it over, oil started leaking from the front right side of the engine near what I think is the govenor assembly. I'm hoping that is just a gasket issue, but is that a common place for oil leaks?

I have lots more questions, but I will just ask one more now. The gas tank is clogged and can't get any fuel to flow. It has some old fuel in it. I have the hood off, is there some trick to getting the tank out so I can drain it? :(
 

It's not the pipe plug, I did not lose that one, it was the other small brass one.
OK, beginning testing.
 

So the part that I lost was a brass part that looked like a carb jet at the location of the right drain plug in the last picture on the page linked above.
I could use a name and a part number so I know what I am trying to buy.

thanks!
 
Lost piece is shown in better detail in second image on this page

http://www.yesterdaystractors.com/articles/restore/8ncarb/artint231_pg3.htm

Here it is called a power circuit plug, or power circuit sand plug, but I have searched for that and can't find it listed anywhere for sale.
 
Is this the little EXTERNAL plug? If so, it is simply a short brass screw with a small head.

Thread is common, # 8-32, IIRC.

It's even listed as a "screw" in the parts catalog.

You can get a brass screw that fits at most any hardware store and cut it to a very short length and install it with a tiny bit of Loctite to prevent any chance of a leak.
 
mvphoto9386.jpg


mvphoto9387.jpg


It's the little plug in the picture. The one that I lost was not a screw, it had a through hole like a carb jet. I have no way of knowing if that was what was supposed to be in there though. I took it out to clean the orifice and dropped it. I thought it was weird that there was what appeared to be a jet there anyway.

If a screw will work, I'm fine with that, just don't want to screw up the air flow.
 
The little external screw/plug in the photo you posted DEFINITELY is not supposed to have a hole in it, and I dug up my notes, and it is definitely a brass 8-32 screw.

You can do as I posted previously and use a brass screw from the hardware store and shorten it and put up with the large head, or buy the correct part (#15-409) from the site linked below, for $4.92, plus shipping.
A reliable carb parts place...
 
sounds like it is not the first time it was lost........
dang, dropped that screw....
what do I have in my junk box....
ah, this old jet has the same threads....
plug the jet hole with some sealer....
screw it in....
back to work.....

use what ya got
 
(quoted from post at 22:37:58 07/20/14) The little external screw/plug in the photo you posted DEFINITELY is not supposed to have a hole in it, and I dug up my notes, and it is definitely a brass 8-32 screw.

You can do as I posted previously and use a brass screw from the hardware store and shorten it and put up with the large head, or buy the correct part (#15-409) from the site linked below, for $4.92, plus shipping.
A reliable carb parts place...

Thanks for the link, I had already scrounged up a brass screw with the proper threads. :)
 
(quoted from post at 03:08:46 07/21/14) sounds like it is not the first time it was lost........
dang, dropped that screw....
what do I have in my junk box....
ah, this old jet has the same threads....
plug the jet hole with some sealer....
screw it in....
back to work.....

use what ya got

I reckon so. I have been know to do such things as well, especially in the field. :)
 
If the "plug" he lost actually had a hole in it, it would have leaked a steady stream of gas as long as there was gas in the tank and the shutoff valve was turned on, as it closes off a passage from the bottom of the float bowl.
 
(quoted from post at 08:25:20 07/21/14) If the "plug" he lost actually had a hole in it, it would have leaked a steady stream of gas as long as there was gas in the tank and the shutoff valve was turned on, as it closes off a passage from the bottom of the float bowl.


There is a steady stream without it in there :), but only with the lawnmower tank rigged up. My tank is so clogged, you just get drips.

I think NNP hit the nail on the head, somebody had already lost the original and put that jet in there with some rtv or something in it.

Thanks for all the help.
 
I am curious to see what the leak is near the governor. I have a similar leak that someone tried to RTV - looks like the oil pan to timing cover/governor mount. No matter how you slice that, it's not good.

I haven't even had a chance to de-grease the monster.
 
(quoted from post at 08:11:20 07/23/14) I am curious to see what the leak is near the governor. I have a similar leak that someone tried to RTV - looks like the oil pan to timing cover/governor mount. No matter how you slice that, it's not good.

I haven't even had a chance to de-grease the monster.

Mine is leaking pretty good, just turning the engine over, I will have to figure out where it is coming from. Like yours though it has so much build up that I can't really tell where it is coming from at this point.
 
(quoted from post at 16:21:02 07/23/14)
(quoted from post at 08:11:20 07/23/14) I am curious to see what the leak is near the governor. I have a similar leak that someone tried to RTV - looks like the oil pan to timing cover/governor mount. No matter how you slice that, it's not good.

I haven't even had a chance to de-grease the monster.

Mine is leaking pretty good, just turning the engine over, I will have to figure out where it is coming from. Like yours though it has so much build up that I can't really tell where it is coming from at this point.

When checking for leaks in that area, clean everything and look carefully. A leaking front crank main seal will 'sling' oil in that direction when the engine is running. Sometimes you are sure it is the governor leaking......but nope
 
Leak is most likely a warped Governor case that won't seal. The case is pot metal and gets warped over time from overtightened. Find a good flat surface put down some emory cloth and work that case until the mounting surface is flat.
 
(quoted from post at 07:47:06 07/24/14) Leak is most likely a warped Governor case that won't seal. The case is pot metal and gets warped over time from overtightened. Find a good flat surface put down some emory cloth and work that case until the mounting surface is flat.

Thanks for the tip!
 

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