How to Rebuild an 850 T3 Engine

The 850 T3 engine is a stock engine featured on Moto Guzzi motorcycles. The T3 was first released on the 1975 Moto Guzzi. Although these Italian-made motorcycles and engines are known for their longevity, the crank bearings and piston rods wear out over time. A significant part of rebuilding the 850 T3 engine involves changing out these parts. It takes approximately three to four hours to rebuild the 850 T3 engine. An assistant may be needed to lift and move the engine from the motorcycle to the workbench.

Instructions

1

Remove the oil drain bolt at the bottom of the oil pan on the engine crank case. Drain the oil into a drip pan and then replace the drain bolt with the socket set.

2

Remove the mounting bolts that hold the engine to the frame of the motorcycle with a socket set. Have an assistant hold the engine in place once the bolts are removed.

3

Transport the engine to the workbench with the help of the assistant.

4

Remove the bolts holding the rocker arms in place with the socket set. Clean these parts with a stiff brush and cleaning solvent and then set the rocker arms and bolts aside.

5

Remove the bolts holding the cylinder head in place with the socket set and then pull it free and set it to the side.

6

Wedge a flat-head screwdriver between the edge of the piston sleeve and the ring clip. Lightly hammer the screwdriver to pry the ring clip out.

7

Insert the screwdriver behind the end of the piston sleeve and tap it with the hammer until the sleeve slides out of the piston. Slip the piston off the piston rod end.

8

Use the socket set to remove the main crank and crank bearings.

9

Remove the piston rod from the crank by taking off the rod bolts with the socket set.

10

Slip the new piston rod on the crankshaft. Insert the rod bolts to the base of the rod and tighten with a torque wrench to 33 to 35 foot pounds.

11

Insert the replacement crankshaft bearings into the crankcase and tighten to 32 foot pounds with the torque wrench.

12

Align the new piston to the piston rod and secure it with the piston clip. Slide the replacement rings onto the new piston.

13

Align the cylinder sleeve with the piston and use a compression tool to force the new piston into the cylinder bore.

14

Replace the cylinder head and use the torque wrench to tighten the retaining bolts to 5.7 foot pounds. Also replace the rocker arms with the socket set.

15

Carry and position the engine back onto the Moto Guzzi frame with the help of the assistant and then replace the mounting bolts to hold the engine to the frame.

16

Open the oil fill cap on the engine and fill with fresh SAE 30 motor oil.