How to Replace the Engine in a Catalina 30 Sailboat

Removing the Existing Engine

• 1

  Slide the hatch cover off the top of the engine enclosure. Remove the eight screws holding the front and side panels off the engine bay, using a Phillips-head screwdriver.

• 2

  Place a shop rag beneath the quick-connect fastener holding the fuel line to the carburetor, and detach the fuel line from the carburetor. Remove the cable retainer screw on the throttle arm using a flat-head screwdriver. Pull the cable trunnion from the anchor pocket to disconnect the throttle cable from the throttle arm. Remove the shift cable retainer screw from the shift arm on the side of the transmission and snap the shift cable trunnion from the support tower on the transmission.

• 3

  Move to the starboard side of the engine. Open the hose clamp on the saltwater supply line that provides cooling water for the exhaust manifold. Remove the hose from the fitting. Remove the four bolts from the drive adapter that secures the propeller shaft to the power take-off at the rear of the transmission, using a 9/16-inch socket and ratchet. Remove the hose clamp from the seawater pump on the forward end of the engine and pull the hose from the fitting.

• 4

  Move to the port side of the engine. Loosen the two screws on the exhaust flange at the rear of the engine. Push the exhaust riser away from the engine. Open the hose clamp and disconnect the bypass hose from the fitting above the freshwater circulating pump at the front of the engine. Disconnect the freshwater circulating pump hose. Remove the temperature sending wire from the sender.

• 5

  Place the hooks of a towing chain in the lifting eyes on top of the cylinder head and the top, center of the transmission.

• 6

  Instruct the crane operator to lower the crane's whip line -- the single line without the block and tackle for heavy lifts. Set the towing/lifting chain over the whip line's hook. Instruct the crane operator to lift only enough to put a slight strain on the chains. If either chain has slack in it, instruct the crane operator to lower the hook enough for you to readjust the chains.

• 7

  Remove the nuts from the four bolts connecting the flexible engine mounts to the universal mounts on the engine bed with a 1-inch box-end wrench. Remove the bolts from the universal mounts.

• 8

  Signal the crane operator to raise the engine. Guide the engine from the engine bay to prevent it from damaging the enclosure.

Installing the New Engine

• 9

  Bolt the new universal mounts in the engine bed if the new engine is not the model as the engine removed from the vessel. The mounts for the M25 are 11.5 inches apart, whereas the mounts for the Atomic 4 are 14.5 inches apart; the Catalina 30's engine bed accommodates both mountings.

• 10

  Lower the engine and transmission into the engine enclosure. Guide the flexible mounts on the engine and transmission to the flexible mounts on the engine bed, carefully aligning them. Remove the lifting slings.

• 11

  Insert the four pairs of mounting bolts through the flexible engine and transmission mounts. Thread the nuts onto the bolts and loosely tighten.

• 12

  Lever the front of the engine upward with a pry bar as much as necessary to align surfaces of the drive adapter on the propeller shaft and drive adapter on the transmission. Install steel shims between the universal mount on the engine bed and the flexible mounts on the engine. No shims are necessary at the transmission mounts. Install the four bolts through drive adapter halves and tighten to 55 foot-pounds with a torque wrench. Tighten the mounting bolts to 35 foot-pounds.

• 13

  Push the freshwater circulating pump hose onto the fitting and tighten the hose clamp. Reconnect the freshwater pump's bypass hose. Push the exhaust riser onto the exhaust flange and tighten the two screws that hold it into place. Reconnect the sending wire to the temperature sender.

• 14

  Reconnect the seawater pump supply hose. Reconnect the saltwater supply line to the exhaust manifold.

• 15

  Secure the shift cable to the shift arm on the transmission with the shift cable retainer screw. Adjust the cable lash, and snap the shift cable trunnion into the the tower support on the transmission; adjust the lash of the shift cable. Secure the throttle cable to the throttle arm on the carburetor. Adjust the cable lash, then snap the cable trunnion into the trunnion anchor on the carburetor. Push the fuel line quick-connect onto the fuel nipple on the carburetor.

• 16

  Set the front and side panels of the engine enclosure into place and secure with the eight screws that hold each. Slide the hatch cover back onto the top of the enclosure.