Cub power

Sun Jan 18, 2004 9:05 am

Hi All,

Well, yesterday I bought a 1951 Cub. It is in very nice condition. It was said it had been restored about 5 years ago. I'm not sure if the engine are anything else was rebuilt. I did discover that the gen isn't puting out.

A couple of questions I have is:

1. It has been many years since I operated a Cub, but this one seems to not have the power I remember. When running the belly mower in first gear it will barely go up a small grade without bogging down.

2.Also, since the gen dosen't seem to work, I was thinking of converting it to a 12 volt.
What is involved in this? Are there kits out there to do this in a simple way?



Sun Jan 18, 2004 10:21 am


I bought a '49 last year and had some problems myself with power. Perhaps all you need is a good tune-up. Check compression, timing and also a well tuned and adjusted carb will save you lots of grief. I am very pleased with the '49's ability to push snow. As far as mowing goes, someone else will have to respond as I have never tried to use a belly mower, but I'd love to try.

Sun Jan 18, 2004 10:42 am

EZ is right, you need to go over the tractor and do a tune-up etc. Check the governor to make sure it is working as well.
As far as the 12 volt conversion goes - it's your choice. But most cubs have functioned quite well with 6 volt systems for over 50 years. It is a very basic system and routine maintenance will correct a lot of issues. Good clean connections on the cables and perhaps polarizing the system may be all that is necessary to restore it to a functional system. I'd try that first before considering a conversion.

Sun Jan 18, 2004 11:03 am


Try cleaning your main Jet in the carburetor. You can screw it out easily and spray some carburetor cleaner through the small hole in the middle of the screw. My cub was losing power and this cured the problem.


I had the same problem ,

Sun Jan 18, 2004 11:04 am

when I first used my Cub with a 59"Woods deck mower ! Not enough power. Go thru the fundamental tuneup, check out proceedure, then make sure the PTO is working properly and "sit back" and be satisified with what you got .That used engine isn't putting out the new power as it used too, so you have to understand that it has limitations. My sole belief is, after mowing with one for 5years , the Cub isn't strong enough to run a mower like it should , espically if you'r lawn is hilly. The newer one , the International, is much better because of it's increased hp.

Pushing snow vs mowing

Sun Jan 18, 2004 11:11 am

Pushing snow , with wheel weights and chains is a snap ! It's much easier than mowing espically in high grass. My 6 volt system works fine , a little lazy in starting but once going OK I have a SA with a 12 volt system , it kicks right like "now" , the Cub "growls" a little first before she starts . Leave it original .

Sun Jan 18, 2004 11:48 am

Maybe you need to look at the mower as well as the tractor. How much power the mower requires will depend on the grass (height and type), how sharp the blades are and adjustment of the mower. Check into all those items as well as the tractor itself.

Cub Power

Sun Jan 18, 2004 4:38 pm

Thanks to all for the replies!!

I will try some of the things suggested.

When I was a young teen the Cub I operated didn't have a mower deck, so I'm not familar with what is normal. At only 8.9 hp it seems as asking a lot out it.

It sure is nice to have my hands on a Cub again. :D :D
Jusy driving it around the yard brings back a lot of good memories.



Sun Jan 18, 2004 7:30 pm


I forgot to say..........Congratulations on your purchase of a '51 Cub!
These little tractors can give you fits at times but for the most part they are very reliable. I really enjoy mine. Hey, they are not the fastest off the lot, but in my eyes they are the best looking. I just spent a couple hours on mine pushing snow off my and my neighbors driveways. Does a real nice job, smooth as a pooltable.
Get yourself a good manual for service, and good luck with getting it top shape. Any pictures?

Sun Jan 18, 2004 8:11 pm

Ron, I bought my Cud about 7yrs ago. Brought it home with a woods 59 mounted underneath it. backed off the trailer and went straight to the yard a mowin in 2nd gear no problem. I know others who said they had to mow in 1st because of the lack of power. Mowing is probably what will extract the most power from it and if anything is marginal like compression, fuel, or tuning it will show up there. Don't worry much about the HP rating. That engine has already outlasted generations of other equipment and will serv for many years to come.

Tue Jan 20, 2004 8:49 am

Good choice for a tractor there! Won't send ya to the poor house to get one.....maybe the nut house by owning one though!! There's lots of great tips in the previous posts. I'd say it's best to do them all and then you can be sure each area is working to potential. One or two things off a bit will give poor perfomance for sure. Once you have fuel and electrical gone over; timing is crucial. (new spark plugs are worth their weight in gold too) My Loboy didn't have much UMPH for the 60" belly mower when I first got it. My IH EXPERT down the road came over and adjusted the timing. Mine has the distributer. He adjusted the timing by ear with the tractor at full throttle and the mower engaged. What a difference! I was then able to mow (lawn) in 2nd gear no problem. I totally rebuilt each of the 3 spindles and put on fresh blades and it even did better! I got the bearing races; bearings and seals from Applied ?????Whatever Bearings Inc turned into, and the blades were available directly from Case IH for about 14$ each.

It will be a bit of a challenge to get her purring but after that it's all smiles :D :D :D

Tue Jan 20, 2004 11:11 am

Congratulations on your '51. My 1947 is primarily a mower. It has a 4 foot belly mower. Once the tractor is warmed up, it pulls the mower fairly easy in 1st gear. After I get her going in 1st and need to go to 2nd, I just speed shift her. I cut about 2 -1/2 acres of flat lawn. I try to keep the blades sharp and make sure that all of the grease fittings are checked regularly. Last summer after mowing in 2nd for an hour or so, it started to rain slightly. I only had a couple of passes left and wondered what she would do mowing in 3rd. Shifted her up and she took it fine. Would not do this regulary because it is really too fast for mowing and I could see where you could tip easily if you cut a corner too fast.
I did all of the things the other guys have mentioned here and recommend them. I have new plugs, wires, distributor, coil, etc.
Good luck,

Wed Jan 21, 2004 8:05 am

:shock: :? SPEED SHIFT FROM 1st to 2nd???? WITH THE PTO ENGAGED ?????? YIKES....That can't be a good thing...?

Wed Jan 21, 2004 10:07 am

That is one of the reasons there is a good market for used transmission gears.

Wed Jan 21, 2004 12:32 pm

Some what suprised at the reaction. I am sure not everyone does this, but I have seen it done many times. Even saw a lot of it at the Cubarama last year in the obstacle course competition. I have done it on different tractors when needed. Even got used to double clutching our old 1967 International Pumper in our local fire department. This is not ramming it into second with grinding of gears. It is tapping the clutch and going form 1st to 2nd with the engine, transmission and PTO all going. Usually slides right in and I keep right on going along. If you are grinding a lot of gears then you are doing some damage. I might be doing some too, but it seems to work for me. I would like to hear more from you guys out there who have torn into the transmissions and learn what you have found.
May have to rethink the way I shift :shock: