Cub dies when under load

[EZ]

Hi guys,
My faithful '67 Loboy has provided many years of snow pushing with no problems, but lately it cannot handle being under load.
The tractor will just die out when I get it to the snow bank for the final 'push'. Also will die when coming out of a grade in reverse.
Buddy said it could be the governor, but the spring seems strong and the tractor runs like a charm.
Any ideas?
Possibly fuel delivery?
I've cleaned/drained the carb.
Sediment bowl is clean, no crud in the tank.

[staninlowerAL]

Suggest you take a look at the air filter cleaner assembly and make sure that it's not dirty or the oil in the cup is not too thick for cold weather. It's probably a long shot but it could be not enough air getting through when the governor kicks in and the engine is under load. Glad I don't have snow removal chores in south Alabama!!

[John *.?-!.* cub owner]

Another thing to look for is water in the air cleaner bowl mixed with the oil. Once it turns to ice it really restricts the flow.

[Rick Spivey]

One other thing to check for is a weak spark.

[Bigdog]

Check your float - could be sticking / hanging up on the bowl or drop is not set right.

[Don McCombs]

[Lurker Carl]

Check ignition system first - the points gap shrinks and timing retards, power goes down. Look for water in the tank. These have been my top gremlins.

[challenger]

With respect to breather concerns, you can perform a test by simply disconnecting the breather hose at the carburetor and running the tractor awhile with the hose off to see whether the engine performance improves. If engine performance improvves, you have a breather issue.

[EZ]

Thanks for the suggestions guys,
I will be checking it out today hopefully.
I shall start by looking at the breather, then, plugs and the points.

[Puffie40]

Check your main jet setting as well - yank the throttle open and listen to it as it accelerates. If it stumbles as its revving up, the main jet is too lean.

[Smokeycub]

yank the throttle open and listen to it as it accelerates. If it stumbles as its revving up, the main jet is too lean.

...or the plugs or coil is weak.

[EZ]

Finally.....Had some time last night to bring the '67 Cub Loboy into the shop.
Pulled off the hood, (always a good thing to do )
I am sure now the problem solution winner is Lurker Carl. sorry no prize
The points were almost fully closed! Not even sure how it was starting with practically zero gap.
The stationary point was like a bowl. Anyhows, I filed that clean and reset to .20.
Also while the hood was off:
Re-torque head bolts to 45 ft. lbs.
Free up the stuck throttle lever on the governor. ( Been stuck for last 2 years but I run at full throttle and rarely idle. i.e. get the job done and put 'er away.) Should save on gas now though!!!!
Lube the fan hub.
Lube the generator.
Clean the distributor. (Rotor spring was broken i.e no metal left, and barely contacting the dist. Lucky the 130 has the same rotor, so I borrowed it)
Clean and check plugs/gap OK. (No oily sludge, nice and brown and clean.)
Change the oil bath, (slight bit of water, 1 tsp)
Grease job.
Top up the rad.

The hood went back on......purrrring like a kit, and pushing snow with full power in second gear with nary a hiccup!

Thanks for the help guys.
Keep up the good work!

[oldhammerhead]

Great sounds good. Glad you said something about stuck throttle lever on the governor,that never gets oiled to be kept free.

[BigBill]

Don't forget to lube the distributor cam so the fiber block on the points doesn't wear and close up the points. They do have a lube for ignition points. A tad of white lube or vasiline will do.

[CraigKennedy]

May be bad spark plug, wires, coil, distributor cap, get a inline spark tester and check your spark on your wires, then replace plugs if spark looks good then dis. cap then coil.
my friend had a john deere z-track lawnmower that would run just fine at idle, then cut the blades on and it sounded like crap and wouldn't cut for s#*t, finally figured out one of the spark plugs was bad. (2 cylinder)