1948 Deere B

thanks for the help

ANSWER= YES.

STATEMENT & QUESTION: I pulled it all the way open with the linkage all hooked up and the flat spring on the govenor pulled away about 2 inches. The throttle butterfly came all the way open and hit the stop. Is this supposed to happen?

ANSWER= YES - THIS IS NORMAL. Proceed as follows

(1) Free up and align all linkage to remove any binding. Adjust or renew any parts causing lost motion, and DISCONNECT throttle rod at carburetor.

2) With throttle handle in FULL SPEED position (engine not running), adjust the length of the carburetor throttle rod so that the rod is 1/2 hole short from entering hole in carburetor throttle shaft lever when carburetor butterfly is in wide open position. RECONNECT throttle rod at carburetor.
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This is not too terribly hard. Let us know how it goes.
(PatB)

Dynamic physics tells me that the engine would not speed up and slow down over the course of several hundred or even tens of revolutions if the flywheel/crankshaft/clutch driver were out of balance. If the CG were off location from the center of rotation, the result would be a lumpy or shakey event on EVERY ROTATION, ergo, a surge on every revoltion, which would be an intense vibration. Paint shakers don't speed up and slow down, they just shake. Pretty typical of a two banger with a flyhweel or clutch driver out of rotary index location.

Though it has already been stated, the first thing I would check is the static governor setting. Sounds like a prime candidate to me. Next, binding linkages, and then air leaks. Vacuum leaks can cause surging.

Frank

Kent

The flywheel: The deep keyway of the flywheel should be placed over the locating screw on the crankshaft; or if the wheel carries a rivet, the rivet should be engaged with cutaway spline on crankshaft. Either the locating screw or flywheel rivet would have to have been missing for you to have installed the flywheel out of time (and out of balance). Assuming the tractor operated OK before the flywheel incident, a quick way to check flywheel timing goes like this: (1) Remove the valve cover, (2) Check to ensure tappet adjust for the # 1 exhaust valve is set to 0.020 inch, and (3) Rotate the flywheel in normal direction until the # 1 exhaust valve is just beginning to open (0.000 tappet gap) -- STOP the flywheel. At this time, the flywheel mark L.H. EXHAUST OPEN should be in register +/- one-inch of the index mark on gear case (3:00 o'clock). If this test fails AND no other work has been done to the tractor to affect the relationship between crankshaft & camshaft -- remove & reinstall flywheel so this test is passed.

Surging: This is a bit of a subjective term, but from the way you have described things -- I can easily believe the governor throttle linkage adjustment needs to be revisited. Proceed as follows (1) Free up and align all linkage to remove any binding. Adjust or renew any parts causing lost motion, and disconnect throttle rod at carburetor. Then (2) With hand control in full speed position (engine not running), adjust the length of the carburetor throttle rod so that the rod is 1/2 hole short from entering hole in carburetor throttle shaft lever when carburetor butterfly is in wide open position. Reconnect throttle rod at carburetor.

Carburetor Testing: I don't really see the carburetor at direct fault here just yet, but if -- after acting through the steps outlined above, you are having grief, you may elect to run the two no-wrench tests to ensure both sides of that carb are truly open. For these, go to the JD-H Restoration Site (below) and once there, one-click on CARBURETORS over on the left side of the Home screen. The test for open pathways is on page 7 or 8. Run those so as to be sure, and then we go from there. (PatB)

• Restoration SIte, JD-H