Blue Smoke - Thoughts?

[1948Ford8n]

Good Evening Everyone,

Just had a question, finally got our 1948 8n, front mount, 12v conversion, electronic ignition and now it’s up and running, I would say that it hasn’t ran in about 15-20 years, I have changed all fluids, new spark plugs and wires, but it has blue smoke when giving throttle and not sure if that could be from it not being started for so long and it’s burning off the crud built up in the engine? This was the third time running and driving, most I have ran it is about 10 min. Has anyone else experienced this and with time will it clear or anything that can be added to burn this off quicker? I hope it’s not the seals or anything engine related. Any knowledge is appreciated. Thank you all.

 

[used red MN]

Hello 48N welcome to YT. Will the smoke clear up? Maybe. Might it be a greater possibility that the engine in a 77 year old tractor is wore out, yes?!

I hope it’s not the seals or anything engine related.

You are in luck here, it is probably not seals. Sadly it probably has to do with the pistons, rings and cylinder sleeves.
Enjoy your new tractor!

 

[Ultradog MN]

Good Evening Everyone,

Just had a question, finally got our 1948 8n, front mount, 12v conversion, electronic ignition and now it’s up and running, I would say that it hasn’t ran in about 15-20 years, I have changed all fluids, new spark plugs and wires, but it has blue smoke when giving throttle and not sure if that could be from it not being started for so long and it’s burning off the crud built up in the engine? This was the third time running and driving, most I have ran it is about 10 min. Has anyone else experienced this and with time will it clear or anything that can be added to burn this off quicker? I hope it’s not the seals or anything engine related. Any knowledge is appreciated. Thank you all.

Hook a mower or plow to it and work it HARD for a few hours. I've had them that sat for a long time clear up for me. - not 15 or 20 but 5 years at least.
Then do a compression test.

 

[Jim in LA]

Good Evening Everyone,

Just had a question, finally got our 1948 8n, front mount, 12v conversion, electronic ignition and now it’s up and running, I would say that it hasn’t ran in about 15-20 years, I have changed all fluids, new spark plugs and wires, but it has blue smoke when giving throttle and not sure if that could be from it not being started for so long and it’s burning off the crud built up in the engine? This was the third time running and driving, most I have ran it is about 10 min. Has anyone else experienced this and with time will it clear or anything that can be added to burn this off quicker? I hope it’s not the seals or anything engine related. Any knowledge is appreciated

I hope your engine doen't require rebuild. It is amazing to me that an 8N can be wore out, smoke like Betty Davis and still start right up and run smooth as glass. We ran our '49 for probably 20 years with leaking head gasket (confirmed during rebuild years later) you could fog mosquitos with it. Always started easy and pulled the old model12 Bush Hog and cultivator without fail. It sat for 17 years before I was able to make time to rebuild it. It would get a can of STP with each oil change. The crank and rod bearings were nice and shiny.

 

[Tall T]

Good Evening Everyone,

Just had a question, finally got our 1948 8n, front mount, 12v conversion, electronic ignition and now it’s up and running, I would say that it hasn’t ran in about 15-20 years, I have changed all fluids, new spark plugs and wires, but it has blue smoke when giving throttle and not sure if that could be from it not being started for so long and it’s burning off the crud built up in the engine? This was the third time running and driving, most I have ran it is about 10 min. Has anyone else experienced this and with time will it clear or anything that can be added to burn this off quicker? I hope it’s not the seals or anything engine related. Any knowledge is appreciated. Thank you all.

One old diagnosis was that blue smoke was relative to valves
and white smoke to the rings.
Maybe it is asking for a valve job.

 

[BradCNY]

Blue smoke on start up on an over head valve engine is valve seals. This coming from my father who was a long time mechanic and hid hundreds of valve jobs in the 60's and 70's.
Blue smoke all the time is rings, either stuck from sitting or a worn out engine.

 

[6 SLY PLACE]

Do you have smoke coming out of the oil fill tube?

 

[Mad Farmer]

Good advice so far. If it runs OK and does not foul plugs run it for a while.

A compression test will give you an idea if things are worn and/or rings a little stuck from sitting.

Did you service air filter oil? Too much oil or level raised up from crud/water will cause engine to suck oil.

 

[1948Ford8n]

Do you have smoke coming out of the oil fill tube?

No smoke out of the oil fill tube.

 

[1948Ford8n]

Good advice so far. If it runs OK and does not foul plugs run it for a while.

A compression test will give you an idea if things are worn and/or rings a little stuck from sitting.

Did you service air filter oil? Too much oil or level raised up from crud/water will cause engine to suck oil.

Oil filter and oil has been changed and also the oil filler cap has been cleaned.

 

[Eman85]

Run it and keep an eye on fluids. As long as it has oil pressure and doesn't overheat run it. Maybe it will clear up some, if not then you'll have to decide if you care enough about it to sink a bunch of time and money into it. If it continues to smoke the usual fix is a complete engine rebuild.

 

[bob p mn]

A lot of people will call it snake oil, but I have cleaned up a few old tractors that smoked badly after sitting for several years by running Seafoam in the gas tank. I would certainly give it a try if it doesn't clean up the smoke you're not out that much. The last one I did was on a Buddies 8N that had sat for years, it smoked like that at first but cleared it right up. I know it will not always be the case but if the rings are partially stuck from sitting you have a chance. Good luck.

 

[ASE guy]

I would run compression in all cylinders, and if good, give it about a cup of tranny fluid and run it pretty hard for a while as long as I had good oil pressure when hot idling.

 

[soaked]

Oil filter and oil has been changed and also the oil filler cap has been cleaned.

Pardon me for asking, but did you check the AIR filter?
In post #8 Mad Farmer posted a " get out of jail free card"----- meaning the suction through the carb may be emptying the AIR filter oil bath if its level is too high, and that would cause blue smoke. (Not crankcase oil and filter.)