86840A 3 Mercruiser BELLOWS ASSEMBLY

Start By:a. remove cylinder headb. remove oil pan.c. remove oil pump and balancer, if so equipped.d. remove cooling jets 1. Check the connecting rods and caps for their identification and location.2. Remove rod cap nuts (1) and the cap from the connecting rod. Remove the lower half of the bearing from the cap.
To protect the crankshaft from the threaded portion of the connecting rod bolts, cut a short piece of rubber hose and install it as illustrated.
3. Remove the piston and connecting rod, then remove the upper half of the rod bearing. The following steps are for the installation of the pistons and connecting rod assemblies.4. Put clean oil on piston rings, connecting rod bearings and cylinder bore.5. Position the piston ring end gaps 120° apart and install tooling (A).
Typical Example6. Put short pieces of hose (2), in place, to protect crankshaft.7. With number one crankshaft throw at bottom center, install piston and connecting rod. Some engines use pistons which have the word "FRONT" stamped on the crown of the piston. Make sure the word "FRONT" is toward the front of the engine when the piston is installed.
Typical Example8. Taking care to line up connecting rod and crankshaft, carefully tap piston into cylinder bore until tooling (A) comes off the piston.9. Before connecting rod comes in contact with crankshaft, install upper half of rod bearing. Be sure the bearing tab engages the groove in the connecting rod.10. Put engine oil on upper rod bearing surface, then tap piston down, guiding connecting rod onto crankshaft.11. Position lower half of rod bearing in corresponding numbered rod cap. Be sure the bearing tab engages the grove in the rod caps.12. Put engine oil on the lower rod bearing surface, then install the rod cap. Install the bearing cap on the connecting rod with the number on the bearing (rod) cap on the same side and same number as on the connecting rod.13. Put engine oil on the threads of the bolts. Install rod cap nuts (1) and tighten them to a torque of 54 7 N m (40 5 lb ft).14. Put an alignment mark on cap and nut. Then, tighten each nut an additional 1/6 60° 5° (turn).15. Repeat the steps for the remainder of the pistons and connecting rods.End By:a. install cooling jetsb. install oil pump and balancer, if so equippedc. install oil pand. install cylinder headDisassemble & Assemble Pistons & Connecting Rods
Start By:a. remove pistons and connecting rods 1. Remove snap ring (1) remove piston pin (2). Separate piston (3) and connecting rod (4). 2. Use tooling (A) and remove the piston rings. The following steps are for the assembly of the pistons and connecting rods.3. Check the clearance between the ends of the piston rings. See the topic, Pistons And Rings in the Specifications module FORM No. SENR3582. The oil ring is to be installed over the spring with the end gap 180° from the oil ring spring joint.4. Install the oil ring onto the piston with tool (A).5. Install the second (intermediate) piston ring with the marking "UP-2", toward the top of the piston. Use tool (A) to install the ring.6. Install the first (top) piston ring with marking "UP-1", toward the top of the piston. Use tool (A) to install the ring. After the installation of all three piston rings, put the piston rings in position so the end gaps are 120° apart.
Verify for the correct assembly of the pistons and connecting rod assemblies. Be sure the stamped word "FRONT" and the stamped numbers on the rod and rod cap are in position as illustrated. The stamped number on the rod and rod cap designates the cylinder in which it should be installed. Also the stamped numbers on the rod and rod cap should be on the side nearest the camshaft.
7. Put the piston in position on connecting rod (4). Coat pin (2) with clean engine oil and install. Install retainer rings (1) with tool (A). Make sure the retainer rings are in the grooves of the piston.8. Install bearings (3) in the connecting rod and connecting rod cap.
Be sure the tabs in the bearings are in the tab slots of the connecting rod and connecting rod cap.
End By:a. install pistons and connecting rod assemblies