Super A stutters dies under load

Hi guys! For several years I've been looking for a Super A like the one I learned on in my youth. (That tractor was sold-w/o my knowledge-, along with attachments, including a Sears post hole digger, while I was away from home for a few years.) The other day I finally found one in decent condition for a decent price, and a belly mower to go with it, and I found that after 30 years the Super A seat still fits cozily! (Ahhhhhhh!) The problem is, when it's under load of cutting taller grass and the governer kicks in, it begins to stutter and dies if not clutched immediately. I remember these little tractors having better load-handling ability (I snaked logs w/our old one), so I'm thinking something is "amiss". The load doesn't have to be much for this to happen, just enough to even begin to strain. The previous owner said it could use an engine overhaul but could probably get by a while w/o one, but the only time I see any smoke is when it does this and then right afterwards black smoke blows for just a second, until it "catches up" (while clutched) and runs normally. I'm thinking carb' or perhaps restricted airflow or even timing/ignition, but I just bought it and haven't gone over it and I don't have any maunuals or spec info yet, so I'm tossing it to you more experienced fellows in hope of a quick and easy fix before I go tearing into stuff. (I'm hoping to get by cutting grass w/it this summer and possibly overhaul the engine this winter, if it really needs it.) Any ideas or similar experiences, folks?

Rad Red

Black smoke is rich mixture. Adjust carb. I take it you are in warm climate and tractor is warmed up. Some tractors you gotta run half choke for may be 5 minutes. Is gas clean?

Your carb is not adjustable, except for the float and idle. Main mixture is a fixed jet. Disassemble, soak in carb cleaner overnight, blow out with compressed air, and put a kit in. Could be ignition, but it sounds like the carb. Disassembly is self explanatory -- or refer to the parts section on www.caseih.com. The kit may include a diagram.

Also, as stated by Dave, make sure you have good fuel flow -- tank outlet, sediment bowl, gas line, filter inside carb where gas line attaches must be clean.

Thanks, CNKS and Dave. I did clean (scrub) the sediment bowl (a well named part). I know it hadn't been cleaned for quite a while, because it had about 1/4" to 3/8" of fine clay settled and "set up" solidly in the bottom (seriously) and I found a small trilobyte fossil between layers of sediment (not seriously). I wasn't aware of the filter inside the carb (thanks again), I'll get that next and plan on a carb kit soon, at which time I will flush the fuel system from tank to carb.

Yes, Dave, I'm in MS, so warming up is no problem. In fact, the tractor cranks right up now w/o choking at all, but with the throttle set at about 1/2 way. The throttle seems "loose" or not adjusted right, because the rpm doesn't increase smoothly/proportionately and the same position runs differently according to if you're increasing or decreasing throttle (seems to lag- sticky internal carb parts?). Also, the tractor will idle well at very low rpm if you slowly work it down all the way, but if you drop to 1/4 throttle from full throttle, it dies. It just seems very "sloppy". When I get the grease cakes off I'll be able to better see what's going on and what can be done from the outside, if anything.

Dave, I thought about the black smoke/rich mixture angle- it seems to indicate to me that the engine is flooding when under a load, right? If the main mix is a fixed jet (as CNKS said), could the wrong jet size have been put in at one time? I'm not familiar w/the governor system, could it be flooding the engine when it kicks in under load? Is that a separate carb circuit? And the black smoke/rich mixture indicates that, no matter how dirty the fuel, lack of fuel doesn't seem to be behind this particular problem (unless the gas was so gritty for so long that it sand-blasted the jet to a larger size). Anyway, at this point, more investigation is called for, and now, armed with new info, I can proceed a bit further.

I know I have a lot of work and tinkering to do to get this old baby up to where I want it and I appreciate you guys taking the time to offer your suggestions and experience. I know it would be much harder to do without your help. Thanks again!

Rad Red