Yamaha 2HP 2-Stroke Outboard Motor Inspection

• Action: To Do List item A0065 - Inspect and perform routine maintenance on Yamaha outboard motor.
• Completed: Started
• Cost: $642.89

Click to go to Yamaha Outboard Motor Repair.

Our new-to-us Yamaha outboard motor was previously mounted on the starboard side of Indra's boomkin on the stainless steel tubing. We had transported the outboard motor in our Ford Ranger truck bed on our return trip to Cebu from Indra at Holiday Oceanview Marina, Samal Island with the intent of checking it out and performing routine maintenance - To Do List Item A0065.

The identification plate on the outboard motor had some numbers visible but did not identify the year or model.

We found the original purchase receipt aboard which identified it as a Yamaha 2 horse power outboard model number 2CMH serial number 6F8K S 1015882. The letter "K" on the identification plate is the year model code which indicates it is a 2006 model which agrees with the purchase receipt dated year 2006.

We did find an owners manual aboard but searched the internet and found a more current one which we downloaded. We also found a few websites that had detailed part breakdowns of the outboard motor and listed parts available for purchase. The part breakdown diagrams were downloaded and used as a guide to disassemble and inspect the motor.

The outward appearance of outboard revealed a "few" issues:

Opened the gas cap and found a little fuel still inside the tank, however it had a layer on it that looked like congealed varnish - probably since it had been there now for 2-plus years.  Removal of the rusty spark plug reveled it was saturated with a oily tar substance.

Next step was to disassemble and check out the state of the impeller - which turned out to be more challenging than it should have been.  Searched the internet and found a few videos detailing how "easy" it was to take this apart to get to the impeller.

I removed the propeller and gear assemblies to access and remove the small circlip at the base of the shaft. The gear housing assembly had very old thick oil in it and was contaminated with grit particles. This was thoroughly cleaned out and the internal bearing appeared to be still serviceable.

With everything properly removed, I attempted to separate the lower shaft assembly from the top of the engine, but no matter what I tried it would not budge.  Back to the internet, low and behold others had this same issue of being unable to get the shaft to separate from the crank shaft - the videos described it as the two parts rusted together and formed a "weld" bond.  I squirted it with WD-40 and gave a few not so gently whacks, but no luck, it would not budge.  Found a text description on a website that advised in this case that the dowel pin that held the impeller in place was really the only thing holding the lower case to the shaft. Advice revealed: beat it harder.  So with a bigger piece of wood and a 5 pound sledge hammer, I gave it what it needed - some TLC - and amazingly enough, about 30 minutes later it was apart.

The propeller shaft was "welded" to the crank shaft and further attempts to beat them apart were futile.  Using a Dremel rotary tool with a metal cutting wheel I cut two groves into the shaft and then used a chisel and hammer to finally separate the two pieces.

Back to why we took this apart; inspection of the impeller showed it was long overdue replacement as almost all the rubber blades were broke off.

The impeller retaining plate was now damaged due to the impeller retaining dowel pin being forced through it, also the two internal oil seals were damaged. One of the broke off impeller blades was stuck in the water inlet severely restricting cooling water flow.

Below are the remains of the water pump assembly, once forcibly removed.

The next step consisted of removing the head cylinder, which revealed the piston chamber was thoroughly contaminated with a thick oil sludge residue - probably the only positive discovery as it at least kept rust from forming in the cylinder/piston area.  After cleaning this goo away, the piston/rings appeared to be good shape.

After thoroughly cleaning everything, wire brushing all carbon deposits/scale away, removing gasket material, the list of replacement parts and additional spares was compiled and ordered from the states from multiple websites.  The total cost (including shipping & tax to our California shipping consolidator) was about $642.89 - might have been prudent to just order a new outboard?  Now to wait the approximately 2-3 months before the parts arrive via ocean freight shipment - Balikbayan boxes sent through Manila Forwarder at about $100 per jumbo box.