Setting Timing

[WildFarmall]

Carburetor was reconditioned and seems to work beautifully. I will check the air mixture screw. Are you suggesting that the fuel to air mixture might cause smoking exhaust?

[Waif]

Carburetor was reconditioned and seems to work beautifully. I will check the air mixture screw. Are you suggesting that the fuel to air mixture might cause smoking exhaust?

Running rich will. It's different than burnin oil, but undigested fuel will smoke. While leaving deposits.
It'll dog /lug an engine in certain ranges too.

If you are getting lots of smoke , but not losing oil level or gaining hydraulic fluid into crank case , something is burning.
There is soot and carbon probably in your engine. Extra fuel can soften some of it.

A compression test will help tell if you have mechanical conditions out of spec too far. If valve clearance and performance is in range of specs first.
An Italian tune up ,(run er hard a while while workin it) after a regular tune up helped my oldest Cub. Rings could have been cruddy.(?)

I get smoke still. But once warmed up and workin it's not overly noticeable except at drops in throttle to idle at times. Or running up from idle.
Fine by me. Some of that is steam before engine is warmed up.
If smoke bellows out of the oil filler cap vent after engine is warmed up after a consistent string of hard starts , and oil level is where it is supposed to be ; on a new/strange tractor there is a problem suspected...

[WildFarmall]

Thanks Waif - I will try the timing light again and check the fuel/air mixture. Oil pressure, if the pressure gauge is correct, seems good. I will keep an eye on oil level to see if it drops any. I assume the oil will change to black quickly?

[Waif]

Thanks Waif - I will try the timing light again and check the fuel/air mixture. Oil pressure, if the pressure gauge is correct, seems good. I will keep an eye on oil level to see if it drops any. I assume the oil will change to black quickly?

Depends on what the oil is flowing through and against.
My oil changes have not resulted in black oil in a short amount of time after a multiple changes on the dirtiest tractor.
The first change was dirty pretty fast. I change a filter each change on the Cubs. Just to be sure. Not knowing their history I want to catch any potential sludge chunks , and keep filter restrictions at a minimum.

I tore down a J.D. 60 that had been run on non detergent oil all it's life.(Or was said to have.)
With an inch or more of hard sludge in the bottom of it , plus all the other dirty places ; running detergent oil in it would probably have never resulted in clean oil for very long.....Not too sure non detergent would have either any more!

Not arguing about type oil or what happened for sure though. It could have been lack of oil changes too. (?)

[WildFarmall]

Thanks. I finally understood the timing light and now my Cub is timed properly with 16 degrees advance. Seems to run good at least to my ears. The problem now is the "smoking" exhaust. It is not real bad but I have put a lot of effort in the tractor and want it right. I am having someone with much more knowledge than me to take a look at it.
I have heard that blue or light smoke is oil burning or oil getting by the rings and blackish smoke is more like a fuel mixture problem. I am wondering if I need new rings or sleeves? I am using 30 weight oil as recommended and I assume it was detergent. My oil is turning dark faster than I would have thought. I just changed the oil and filter about 2-3 run hours ago. Not sure how much sludge may be in the engine but wondering if there is an easy way to get it out short of breaking down the engine?
I guess I will find out more information tomorrow or the next day.

[Waif]

Hang in there.
Not saying yours is such a case , but many old tractors smoke and are still ready to work.
They start hard with bad compression.
On some Cubs they smoke out the oil filler caps filter when blow by is getting introduced to the crank case.
Before they are that bad they smoke out the oil fill pipe when cap is removed.

Until a tractor is worked enough to loosen any potential sticky or stuck rings a compression test could fool you too.

Your oil is working. It gets dirty enough you can just change it again. Meanwhile less deposits on your cylinder walls and head and such.

Give it time. It took many years for your tractor to be smoking like it is. If it had real low compression or mechanical failure , smoke would be the least of your concerns. Because it wouldn't run enough to smoke!

Pat it on the hood while you are listening to that engine run happy. (Just make sure you have ventilation..)

I smell like either tractor's exhaust after driving one awhile. Each smells different, but the same too. Fine by me! They both run great.

[Glen]

Hi,
Good that you got the timing light to work.

Cub engines originally have no sleeves in the cylinders, the pistons run in the block.
The pistons and rings are made in a few oversizes. The engine has to be removed and sent to an engine shop to rebore it.
Blue smoke is usually from oil burning. You didn't say what color smoke you have, or I missed reading it if you did.
The engine could have stuck piston rings, if it is making blue smoke.
The people on here say to add some Seafoam oil additive to the oil, and work the Cub pulling a plow or something for some hours, it can improve the smoking. They sell Seafoam at auto parts stores.

Some Cubs that have not been apart in years need the oil pan removed, and cleaned out, and the oil pump intake screen cleaned.

You could look in with a light through the oil pan drain plug hole, when you drain the oil, and see if you see goop, use a stiff wire and put in and see if there is goop in the bottom of the pan.

The 3 bolts on the rear of the pan are hard to get to, you have to remove the cover held on with the 4 bolts, and the people on here have said use a 1/4" drive ratchet, extension, universal joint, and 1/2" socket, to get the 3 rear bolts out.

Below is the Cub service manual, if you don't have it. It has lots of info, the engine is in section 1.

http://farmallcub.com/rudi_cub/www.clea ... index.html

[outdoors4evr]

Some Cubs that have not been apart in years need the oil pan removed, and cleaned out, and the oil pump intake screen cleaned.
You could look in with a light through the oil pan drain plug hole, when you drain the oil, and see if you see goop, use a stiff wire and put in and see if there is goop in the bottom of the pan.

Seems like the bottom of the oil pan always has some sludge in it. Once you drop the oil pan and clean out the bottom of the pan, it gets a little easier to keep it clean. I park my tractor with the left side on a couple of blocks of 4x4 wood when I drain the oil. It seems to help get more of the old oil out of the engine.

[WildFarmall]

Wow, great info Waif, Glen, and Outdoors4evr! I also greatly appreciate the encouragement. When I started this project about 3-4 months ago I explained that I have trouble sometimes visualizing some things. This is all new to me, even though I am quite capable. What I did not realize was how helpful you and others would be. I appreciate your patience.
1. When I changed my oil I let everything drain out thoroughly and then cleaned everything as well as I could. I used a rag to clean out the filter chamber and I even stuck a rag in the oil pan drain hole and got as much out as possible. I was thinking of pouring kerosene in but did not want to risk it. I will wait a while and then change the oil and filter again and when I do I will drop the oil pan and clean it thoroughly. Is there anything else I should do?
2. I used 30 weight oil - a good brand, but do not know if it was detergent or not. I know that this has been discussed a lot but what would you recommend?
3. Glen - I will check the color of the exhaust smoke again and report back. I will get some Seafoam oil additive and add it to the oil.
4. Waif - Thanks for the encouragement - I am probably obsessing about this too much. I am anxious to do some farming with it as I bought a set of cultivators last fall. Already had a disk and plow.
The best to all.

[WildFarmall]

Here is a picture of my tractor so far. In the background on the left you will see my 1940 Farmall A - anyone want to help with that! Ha!

[outdoors4evr]

Nice looking cub with all the bells and whistles!
That cub needs to be put to work! It picked up a smoking habit from hanging out in the garage!

[Waif]

O.k.. Obsess away ,it's your mule.
Quite the tractor you have. It's purty!
Awesome building the Cub is in too. Scary clean and organised , but I won't turn you in over it , yet.

I'm running Rotella 15W-40 oil. Oil topic is a can of worms , but having one that runs in your climate's current temperature range is the first matter of importance. Followed by it being reasonably clean and at proper level.

As a former "grease monkey " for a living I stuck mostly with manufacturer specs of a lube , with changes for modern equivalents on older equipment.
An engine is not a gearbox. But both operate in a rage of lubes ,with results from un- noticeable ,to ooopsie.
Many gearboxes if of good condition and design are forgiving as long as lube gets where it needs to. Temp range again is a factor.

Engines state of condition factor. As does the distribution of lube where it needs to be and at what viscosity for best flow in varied temp ranges.
Modern oils (nothing against running Case specified oil in a Cub if an owner desires) run circles around old ones.

Really , we get an oil that flows like it should for a first priority. A Cub needs some reasonably clean slippery slide is all.
I know of no miracle type or brand that makes one excel.
If running a fleet , or buying oil in bulk for varied equipment I'd study the properties to see if it could be run in a Cub. And or your A.
And or whatever else you run oil in.
Won't cover everything with one oil probably , but if both tractors are suited for one that is less to keep track of which takes what ,and partial containers of varied types.

[WildFarmall]

The person who I thought would come and look at my tractor today could not make it today and we have rescheduled for Thursday. I am having that feeling that I am on my own with this.
In any case I put Sea Foam in the gas and will put some in the oil later.
I took one of the plugs out and it is pictured below. I showed the picture to an employee at an auto parts store and he said it looked like my cub is getting too much gas. Does anyone know if there is an easy adjustment for this?

[Waif]

If you review carb installation and adjustments you will find how to adjust air fuel screw on it.
But....If you change that adjustment and later change anything else regarding tune ups ,you'll want to change it again.
I wouldn't change it without new sparkplugs. And if the rest of your ignition system has not been tuned up , do that first.

A search for spark plug types for a Cub will show different brands. And hot or cold plugs . Plugs for general putting around , and plugs for hard work.

Don't do this ...But if you ran your Cub a wide open throttle for ten miles and hit the kill switch when at high throttle , it would tell more about your plugs.

The pictured plug I would call sooty.
Nothing unusual about that when/if the tractor has just been putted around an spends more time lugging than grunting..
Proper gap is important. One of the few things I've learned to really fuss about on a Cub.

[MiCarl]

I agree with Waif: That looks like soot, not oil. You need to look at all 4 to find out if it's burning oil because you might have a ring problem on just one cylinder. Oil on the plug will look black and somewhat shiny, not gray and dull like your plug.

As far as the fuel mixture goes did you check the fuel level and not just go by float height? If the fuel leve is too high it'll run rich. The screw only adjusts the low speed/low load mixture. High speed/high load mixture is controlled by the jet.

All engines have some blow by which deposits soot and unburnt fuel in the oil The purpose of detergent in the oil is to prevent that stuff from settling out into sludge, not to clean an already dirty engine. A high temperature engine will tend to keep a lot of that out of the oil but the Cub isn't high temp.

Mine blows white smoke like mad on a cold start and then clears up. I think it must be condensation because it doesn't smell sweet (I have antifreeze in mine), it clears up after a few minutes and I'm not losing coolant.

Here is what I suggest:

1) Look at the other 3 plugs so you can sleep at night.
2) Check the fuel level.
3) Adjust the mixture screw so it idles nice (hot, not cold).
4) Ride like you stole it.

Change the oil at the suggested interval.