Harmful to lug engine?

[punchofdeath]

I've started to wonder if lugging the cub's engine is harmful to it. I don't lug it when I'm doing work with it however... I keep the throttle moved up when working.

Say I'm just cruising around the yard I'll keep the throttle a notch above idle and drive around in third. I can start out at idle or a notch above in third without having to slip the clutch very much.. engine pulls along nicely. My favorite part is the grunt the Cub makes when it starts opening up when you let the clutch out.

I don't have any knocking or clunking or anything when it lugs... just the grunt.
My concern in the end is lugging the Cub's engine like this harmful? It's just a few seconds while it's getting going then maybe a few times over some bumps in the yard.

Sorry if this is poorly written my brain isn't all there at the moment
~CG

[staninlowerAL]

IMO as long as you have sufficient air flow to keep the engine from overheating there should be no problem with running at slow rpm....might experience some excess carbon build up over time if it is not worked hard.

[jsfarmall]

Actual harm, no. As stated above the lack.of air movement will be your biggest problem. I like 2nd gear and half throttle around the yard. Keeps fan spinning fast enough to keep things cool and engine running fast enough to keep carbon out of cylinders and keeps plugs clean.

[Gary Dotson]

Doing what you describe, you're doing no harm. When I have my Cockshutt 20 out, one of my favorite things is to putter around in high gear, engine idling, it just does it so well.

[outdoors4evr]

I've always wanted to have a gear between 2nd and third.
The early 70's cub specifications show 2nd gear (wide open throttle) around 3.2mph and third gear (wide open throttle) around 7.3mph.
I don't travel field to field or down a road, so third is typically too fast. 2nd is fine at wide open, but seems really slow when 1/2 throttle or below.
Wish I could re-gear third to be around 5mph wide open.

[xraycajun]

I feel just the opposite! Third Gear and wide open! The best part of cutting grass on the cub when I was in high school was running back home in third. The breeze was such a relief after broiling in the Louisiana August heat while cutting. Since I've started restoring my cub, I've been having dreams of riding in third gear... bouncing in the seat and hearing the crunch of the driveway gravel

[jsfarmall]

Lol yeah ya got a point. I was talking about putt putt putting around the yard

[IHCFan1950]

I agree with Jsfarmall. 2nd and half throttle. Heck, I even do 1st and half throttle. I don't know why, but there is something about that Cub in 1st that makes it appealing. The gear whine is part of it, but I like going slow on her. You know what I mean? A little "one on one" time with her around the yard? Not just a "3rd gear dash" around and back although you gotta admit, it's pretty fun!

Another thing I wanted to point out. Those C60s are torqy little motors. Even though the tractor is almost a ton, and the engine is only 9 horses, it's all that lovely torque that makes it what it is and enables it to move at idle in even 3rd gear. Getting slightly off topic, but the old V16 Cadillac's back in the 30s had so much torque, you could start off in top gear from a dead standstill and not even bother shifting.

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

Having been raised on a farm using the old H, I have my own theories, many of which I got from my Dad who was a good mechanic. If you have it under a heavy load and are pulling it down to the point you can hear the individual cylinders firing, yeah that is hard on them. just puttering around, with little to no load, no. Puttering around in the yard pulling a light trailer on level ground, no problem, if going up a hill and the engine just barely turning over, it is hard on it.

[Don B.]

My Dad used to talk about our old cars lugging in terms of the amount of gasoline you're pumping into the cylinders while the low rpms slowed the oil pump a little bit. So as he described it, you have a little less oil and a little more gasoline. So you are 'washing' oil off the cylinder walls and thereby slightly accelerating wear.
1. Not sure how accurate that theory is.
2. Not sure it would even apply to a Cub without a fuel pump an no gas pedal to "pump".
I am interested to hear what you all think about that. Dad passed away 15 years ago so you can't hurt his feelings.

[punchofdeath]

Hi everyone, thanks for all of the replies!

staninlowerAL & jsfarmall -- I assume I have enough air flow since the radiator cap hasn't had steam bellowing out of it. I usually do a loop around the yard then go to the neighbors and check on his garden then I'll come back on the side of the road full throttle in third. That'll blow the cobwebs out won't it? I have a homemade scraper blade that's about 5 ft wide and I'll work a sandy road with it sometimes to smooth it out or go push brush down somewhere.

Gary Dotson -- I love everything about putting around in third at idle. My Cub handles it extremely well since I got the exhaust valve working on cylinder #3 again as well as putting a 6v battery on it (Used to just run off of generator.. previous family who worked on it couldn't get it to start on 6v.. I fixed that ). I got it running back in June 2017 then up until May(?) of this year I had no clue it was running on three cylinders. I'll tell ya what though.. I was one happy camper that night when I got it going on all four!

outdoors4evr -- I'll drive around in 2nd gear and I'll use first when I need to go up or down a hill as far as cruising around goes. When I get to a spot where I know I won't rattle my bones out of place I'll put it in third and cruise around. I usually don't drive in third at full throttle unless I'm on the road or just wanting some more wind.

xraycajun -- Yea the heat of the day when working the Cub can really feel like it's cooking ya sometimes. Third gear is a nice relief once your finished.

IHCFan1950 -- I like running around in second a lot of the time at half throttle. First gear is like I can feel the gear whine go in the bone at my rear end then up my back.. Foam on the seat must be getting some wore spots in it . A third gear cruise around the yard at half throttle or lower is pretty relaxing. The engine in the Cub will surprise just about anyone I think. That's an impressive amount of torque but then again that's an impressive amount of cylinders.

John *.?-!.* cub owner -- Yea I don't run mine to the point where I can hear each cylinder firing. Mine doesn't keep perfect oil pressure so I try to keep the rpm's up a little bit

Don B. -- I've heard the thing about "washing" the oil off the cylinder walls like your saying. I've heard starting fluid has a similar effect. I'm not sure how this would work with a Cub either. I figure the gas could still wash the oil off the walls somehow but I can't think of an explanation. The "pumping" a gas pedal is actually referring to the accelerator pump that's put in some carburetors (Usually cars I assume) When you hit the gas in a car that has an accelerator pump then a mechanism would squirt gas into the intake to accommodate for the sudden demand. So instead of the car bogging for a second when you open the throttle up suddenly it'll just take off. Not all that sure if my explanation is on point but maybe someone with more knowledge of the mechanics of it, as well as the terms, could explain it to you better than I did.

[Don B.]

punchofdeath - the accelerator pump was what I was thinking of.
Haha. Shoot, we don't have no fuel pump, no accelerator pump, and no water pump.
That takes a lot of potential problems out of the picture!

[IHCFan1950]

First gear is like I can feel the gear whine go in the bone at my rear end then up my back.. Foam on the seat must be getting some wore spots in it .

Punchofdeath,

That's the whole point. It's supposed to be stimulating! Hey, I got a bare metal seat. No cushion on mine! I gots to feel it all!