- Action: To Do List item A0065 - Inspect and perform routine maintenance on Yamaha outboard motor.
- Completed: 1 April 2016
- Cost: $642.89
Click to go to Yamaha 2HP 2-Stroke Outboard Motor Inspection.
The numerous parts ordered for repair of the Yamaha outboard motor, consolidated and shipped by ocean freight from Los Angeles, California, took 3 months to arrive from the time of order.
The mount bolt area for the zinc was sanded to bare metal and a new zinc was bolted to the lower casing assembly.
The water pump repair kit parts were installed on the lower casing and new water seals were installed in the water pump housing cover. A new impeller was installed on the new drive shaft, drive shaft was inserted into the lower casing, pinion gear and small retaining clip installed on the bottom of the drive shaft, impeller retaining plate installed, and water pump housing cover bolted to lower casing. The lower casing gear housing had the small shaft with drive gear reinstalled, new O-rings, and the gear housing was bolted close. The aluminum propeller was reinstalled on the drive shaft with new shear pin.
A new spark plug was installed into the cylinder head; the piston, cylinder, and rings were lubricated lightly with oil; a new head gasket aligned to engine block; and they were then bolted together.
A new exhaust manifold gasket was installed on the engine block.
The exhaust manifold was installed next with the new gasket for mating to the propeller shaft middle casing assembly.
The new propeller shaft was then attached to manifold/engine assembly. To reduce the chance of corrosion between the propeller shaft and the engine crank shaft, a liberal amount of anti-corrosive grease was put in the top cavity of the propeller shaft before being inserted on the engine crank shaft. The entire new propeller shaft was also coated with anti-corrosive grease.
A new cooling water tube was installed. The engine block, middle casing, and lower casing were carefully aligned to ensure proper alignment and installation of propeller shaft and water tube; then all had mount bolts installed and tightened.
The new fuel stop cock with fuel filter was installed in the base of the fuel tank and a new fuel hose was attached on the fuel cock outside connection to be mated with the carburetor.
The carburetor had been previous flushed and cleaned of all the old fuel residue discovered during initial inspection. Parts from a carburetor repair kit replaced all the original items. The carburetor was mounted to the engine and the new fuel hose from the fuel tank was connected.
A new gas tank rubber seal and gas cap were installed on the fuel tank. The fuel tank was then reinstalled on the outboard frame.
The outboard mount bracket had a new friction rubber plate and adjustment wing bolt with spring tensioner installed. The internal mount areas and bushings were thoroughly greased and the outboard mount bracket was reattached to the upper casing.
A new stop switch with lanyard was installed on the tiller handle, the tiller handle was reattached to the outboard frame, and the wiring reconnected.
Miscellaneous hardware was replaced, the new forward plastic cowling and the rest of the original engine cowling was installed. A new choke switch knob and faceplate decals were installed.
The gear box housing was refilled with SAE 90 weight gear oil. Gas and two stroke outboard oil were mixed per the 100:1 ratio and a small amount put in the gas tank. The outboard was mounted to a drum filled with fresh water. The engine started on second pull, and ran well. Very little smoke was observed and cooling water ejection was strong. Made minor adjustments to the carburetor settings. It was run up to power, then idled for about 10 minutes until the fuel ran out. The spark plug was removed, a small amount of oil was inserted into the spark hole, and then the spark plug was reinstalled. A new outboard cloth sun cover was made using Sunbrella material and fitted on the outboard. The outboard was then mounted back aboard Indra and secured with a padlocked when we returned in April 2016. Project complete!
Post Project Analysis and Summary
A few questions need to be asked and possible answers found; i.e., what lessons were learned from this project.
The first questions is what was wrong/broke and possibly why. The missing or broke parts, broke impeller, and contaminated gear oil were clearly the result of the choice to not perform recommended periodic inspections and basic maintenance. If the impeller inspections were performed every 200 hours or yearly, it is very probable the two shafts would have not corroded to the extent they welded themselves together. If the recommended storage preparations were performed, the discovered fuel contamination issues would not have occurred. The documented previous issues of hard starting were most likely caused by contaminated fuel and filter issues impacting carburetor operation; also possibly due to the extremely restricted cooling water flow, the engine probably ran extremely hot affecting operation.
Was it worth fixing or should purchase of a replacement been considered? A new 2016 Yamaha 2hp model 2CMHS from Australia was US $585.00, not including shipping and customs, which would most likely make the total cost around US $1000.00. The cost of all the parts identified during the initial inspection and ordered, to include spares, was US 642.89; this does not include the time expended. So in this case, it would have been more realistic and cost effective to replace. However, as we had never done something like this before, the knowledge, experience, and confidence gained might tip the scales toward fixing it as more worthwhile. The condition of the outboard was not known at the time of boat purchase, and if known, should have had a negative impact on the offer price.
