After buying my Yamaha 125E I found that it is pretty hard to find a manual to work on it. It’s a little hard to trust most of the parts places that you find in the smaller towns in the Dominican Republic. Most pretty much go by a “if it more or less works, it’s good enough” philosophy. A manual increases your chances of getting the right part and getting the part installed correctly, even if you are just watching someone else do the work.

The Yamaha 125 ED is pretty popular in the Dominican Republic and you can find it at Yamaha dealers in most of the larger towns. It is a bit more expensive than the Honda Cub and even some of the 125s you see from Suzuki. Usually it is far more expensive that the Chinese manufactured bikes that are pretty popular here. However, I’ve ridden several of those other bikes and there is a very large difference in quality, this bike is taken care of will provide many more years of trouble free service than the cheaper bikes.
Maintenance however is the key to keeping these bikes running without major problems and repairs. Here are a couple of points of interest I found from the repair and maintenance manual.

• First the engine oil: In most parts of the DR, 20W-40 or 20W-50 engine oil works well. If you are in Jarabacoa or another somewhat cooler area, you might consider a 15W-40 or a 10W-40. One point of concern is using the wrong oil type. The clutch is lubricated by the engine oil and the wrong type of oil or oil with additives, can cause clutch slippage. For this reason don’t use oil with chemical additives (i.e. slick 50 etc), oils with a grade of CD or higher, or oils that are labeled “Energy Conserving II” or higher. Also it is best to check the engine oil with the engine warm, after warming up the engine wait a few minutes for the oil to settle before checking. When you change your oil you will need to replace it with 1 US qt (manual says 1.06 US qt)
• Spark Plug: Use a spark plug of type CR6HSA (NGK) or the equivalent. Something I’ve found while asking around the local parts places and repair places is that they don’t even know what a spark plug gapper is. The gap should be between 0.6 – 0.7 mm (0.024 – 0.028 in). Apparently they never check the gap and just assume that it is close enough from the factory.
• Engine Idling speed: This is kind of a matter of preference, in the cooler areas you might adjust it a little higher than in the warmer areas but the idle should fall between 1,400 and 1,500 rpm when the engine is warmed up.
• Drive Chain Slack: Of the mechanics that I have allowed to do some work on my bike, all adjust the chain too tight. One had it so tight you could hear the chain clicking as it tried to pass over the sprocket. There should be a movement of about ¾ to 1 ¼ inch up and down in the middle of the chain when it is adjusted right. Also, if you allow someone else to adjust the chain, make sure you check the measuring lines at the rear axle to make sure the rear wheel is aligned with the frame. I’ve only one seen a guy bother to look, they generally only adjust the chain side and leave the other where it is. Both side of the axle need to be adjusted at the same time to align the wheel. There is a lot of rain (and puddles) in the Dominican Republic, be sure to clean and oil your chain frequently, it you start hearing a dry scraping sound you are waiting too long.
• Lubricate Cables: If you ride your bike in the rain much (you don’t always have a choice), you will need to lubricate your cables regularly also. You can take your throttle handle off and put some oil between the handle bar and handle and also oil the throttle and clutch cables. You can use either engine oil or a specific cable lubricant.
• Battery: Don’t forget to check your battery water on a regular basis, there are two lines on the battery, an upper and lower level, the water should be between those two lines. Use only distilled water, do not use bottled drinking water, tap water or well water. While you are at it clean the posts, the moisture and salt air can oxidize the terminals quickly.

Brakes

You’re going to be using your brakes a lot while driving in the DR. Often that includes hard braking (avoiding potholes, cars, motorcycles and Pasolas on the wrong side of the road, kids doing wheelies on their motorcycles and pasolas heading toward you on your side of the road, etc.) not just your normal stop and go braking. Dust, mud and salt air also takes it’s toll on brakes and pads. Make sure your brakes are in good repair. It is pretty easy to check the condition of your brake pads. The Yamaha 125 ED comes with front disc brakes and drum brakes in the rear.

Behind the brake caliper in front you will find a small (usually black) plug. Remove the plug and look inside the caliper. You will see two indicators (#2 in first illustration). If these are close to touching the brake disc it is time to change your front pads.

On the rear hub you will find a small indicator with a swing arm (#1 in the second illustration) when you apply the brakes this arm will move, when the brake pads need to be replaced the swing arm of the indicator will reach the wear limit line (#2 in the second illustration).

Both the front and rear brake shoes come as a set of two pads. While you can replace either the front or the rear brake pads without changing the other, make sure that you always replace both of the front pads or both of the rear pads as a set, even if the wear is uneven and it looks like you could get away with only changing one.

Yamaha 125ed Repair Manual

While this manual is for a 2005 I’ve found that it works for quite a few years. Some of the specifications might change but the majority stays the same. 2005 Yamaha 125 ED Repair Manual

Keeping up on the maintenance is very important. In the Dominican Republic you are going to subject your bike to constant dust from dirt roads, rain and mud and salt air if you live near the coast. In addition to the potholes that knock things out of adjustment you also have the constant braking and swerving maneuvers. While you can find good mechanics in the DR, most of them learn as they go along and have little or no training and often have never even seen a repair manual so have no idea why they need to set things to certain specifications or what they might be.

Before taking your bike in to have it worked on, look over the manual and figure out for yourself what needs to be done and watch them do the work. While this is a good idea no matter where you live and have work done, this is especially important in countries like the Dominican Republic where there is little or no formal training on motorcycle (or car) repairs and maintenance.