How much rebuild?

[kinelbor]

Well I was out plowin today and idled down the cub for a few minutes, when I came out of the garage the blue smoke was really rollin from the stack. I have always noticed some smoke but this seemed pretty bad. I looked down the stack and the oil and carbon is really building up on the weather cap and pipe. It is also running a little choppy, just isnt "sewing machine" I have oil leaking from front seal and around gaskets. The plugs were semi oilly. I havent tested compression for a while. I am willing to do a rebuild and was wondering if anyone had some ideas where to start? Am I going to damage it if I keep running it until spring or should I just let the snowblower do the work from now and start rebuilding now?

[panicmechanic]

kinelbor,
Sounds familiar! I have finially pulled mine down for a rebuild because I was at the same point. I use my cub for snow plowing and mowing and ran it tired for several years. I wondered what I would find. These little tractors are seriously overbuilt for the power they put out. I was amazed how good everything looked inside. Yes, the bores were worn about .004 out of round and .005 taper but in general everything was in incredible condition for 53 years old! Even the valve stems measured close to the upper limit. The crank was just barely past the upper limit and still round.
I just picked everything up from the machine shop tonight. .040 over, new guides, just touched the valve seats with a stone! They were in great shape, and turned the crank .010 under on rod and main just to insure good clearances. I bought all of my parts from the local NAPA dealer through the clevitte heavy duty catalog. (pistons, rings, rod and main bearings, valves, guides, springs, locks, gasket set) for $735. The machine work was $300. Probably will do the clutch too while it is split and what ever other items that need replaced (belts, hoses, wires, plugs etc....)

[Jeff M]

Nik, if you have the desire and $$$ for the rebuild you'll be glad you did. When you started it up when I was there the first thing I thought to myself was, "Gee, that doesn't sound very good," but having just met you I didn't want to come off as The Prophet of Doom. I also noticed just backing up the hill it was noticeably lacking in power. If you do the rebuild you won't believe the difference. These are the smoothest, sweetest little engines in existence--and amazingly so as they are hardly a "cutting edge" design.

Go for it! Then you can do the transmission! And then the left final drive!

[Russell F]

Rebuilt mine this past fall.

Hot-tank block, bore to .040" oversize, and grind valve seats $100

Rebuild kit (pistons, rings, rod and main bearings, gasket kit, vlaves only etc) and a new front pully as old was cracked $500

Misc (shop towels, grease and oils, hard ware, anti-freeze) $60

grand total 660. if i had to do it again i would have had my crank ground, i was just barely in tolerance and don't have quite the oil pressure i wanted, but i have more than enough(25-30 when hot) But i think it'll last till it's time for rings in 10-15 years

I did all the assembly myself, shaved the head myself, boiled the radiator out myself (at work), hot tanked the radiator base houseing and made and installed new bushings and seals, etc.. etc.. etc..

I did it in approx 2 weeks after work in the evenings, and we where having a fall shutdown with lotsa overtime so i'm confident i could have done it in much less time. I finished it in time the second satuday to hook to the belly mower and mow mule patties in the pasture.

The machine shop started on my block the morning i droped it off before work and had it ready the next day. Took me only a day to split the tractor and gut the block. Take a boc of zip lock bags, all the ice xream buckets you can find, and any other odd ball containers. The zip locs are great for small parts like valve retainers and such, and the ice cream tubs are great for larger items (timing gears etc). I had one tub full of a solvent, kinda a poor mans parts washer. It was a fun exp. and i highly recomend it!!

[Eugene]

Rebuild now or later this spring. Your decision.

If you keep the engine full of oil and don't let the engine run without oil pressure - it shouldn't get any worse. If you have little or no oil pressure, rebuild now.

If you want to run the tractor until spring - change the plugs when ever the tractor starts missing - hotter plugs if you can find them.

You might check to see if you have to much oil in the crankcase.

Eugene

[Buzzard Wing]

Nik, I bet Mike O would would be able to hook you up with someone that does that kind of thing up your way. Russell F has the right idea.... you can do most of the 'grunt' work yourself. It will save you a bunch of money and you will learn a lot at the same time.

I really don't know, but I suspect that if you have decent oil pressure and it is only 'burning' oil you should be able to run it without causing any real damage.

Not sure how well it would work, but you may be able to do something like swap a 'power unit' or the components from one for cheaper money than a rebuild. I know someone that has one, but I never looked at it. I may be over there in the next few days so I will try to take a look at it. There are a lot of em around.