I did manage to do a slight workover of the LI over Christmas break. This machine was coughing out a lot of smoke at startup and needed some work. The jug had a few shallow score marks and the piston had some definite blowby. It was bored .005 over at some point in its life.
Also discovered a burnt exhaust valve (always have side air deflectors on your working machines!) and two newer style lifter assemblies with the oil drainback groove.
I checked the taper of the cylinder using Gravely's ring gap method, and it was well within the limit. However, it does need to be bored .010 over because the ring gaps of the new and old rings were just slightly outside the limit. I cleaned things up, deglazed the cylinder, and put in my new set of .005 rings anyway just to try. The exhaust valve was also replaced and lapped in. Note how well the ".005" on the piston showed up in this photo.
I also had to repair or replace the fan shroud, fan, and gas tank so I purchased a parts '66 LI from a forum member. It turns out that my left bottom axle bolt has stripped out the threads in the transmission (sigh), so eventually I will swap out the transmissions.
Fan shroud before and after being welded by a friend with a Harbor Freight 90 amp flux core welder, and some grinding:
Interesting fan - I don't think it's original, but it seems to work well.
Few interesting bits on the parts tractor. I assume this was the last style of jug that Gravely used before the 7.6 style. I snapped off both exhaust manifold bolts but removed one with vise-grips. Actually, everything on this tractor was pretty easy to remove besides the manifold bolts and gas tank strap bolts.
Nice crack in the crankcase from some unknown cause, running up along the right rear corner and along the bottom. The piston, valves, and cylinder didn't look too bad.
Decent looking Hoof governor that I'll redo later on. Most of the linkage is gone but I won't need it for a while. This tractor had one grooved lifter channel and one non-grooved channel.
Anyway, back to the '63. I started taking apart the carburetor to rebuild it but ended up trashing the idle jet - someone before me had stripped out the screwdriver slot. So, I just yanked the carburetor off of my L8 and replaced the float (it needed to be done anyway). I've gotten used to Zenith carburetors, but that darn idle jet always gives me problems because invariably someone else has torn it up.
All back together with the saw. Parts came from GT Enterprises and Richard's. My only issue was with the top end gasket set from Richard's - it was missing both lower lifter gaskets, one manifold gasket, and one of the thin upper valve cover gaskets. I dug out some old gaskets and managed to make a complete set. The side air deflectors came from my L8.
I'd like to reverse the wheel that sticks out like a sore thumb, but it would hit the starter. I'll rotate the axle housings eventually.
An LI with GRWs means you have to constantly watch out for traffic... slow going. It's nice for driving through saplings though. In case anyone's wondering, I used the sulky to ride to the area that I cleared, and then removed it and walked while using the saw.
On the whole, the tractor is certainly better than it was. It does still burn a small amount of oil, but I figured it would since it really should have been bored out with a .010 piston. It runs really nicely until the plug fouls (20-30 minutes?), then it begins to "putt" now and then. I clean the plug before I use it next, and the process repeats. To be fair, I only ran the tractor for maybe 6 hours. The starter clutch really needs to be fixed and the seals need to be replaced on the 106 drive.
Also, when I attempt to perform the high speed mixture adjustment, the manual says the turn the main jet adjustment handle in until the engine begins to slow down. However, the engine never slows down and in fact speeds up slightly as I turn the needle in from the preliminary setting. Anybody know what's wrong? Something I messed up in the carb?
Thank you for your patience. This turned out to be a longer post than intended. Also, a big thanks to all the members that gave me advice when I was formulating a plan of attack for this tractor.