There is no one simple answer to this question. There are many factors which must be taken into account, most importantly is to never exceed the horsepower rating of the boat. Other factors to be taken into account are the weight of the boat, weight of passengers/gear, and your expected use of the boat (do you want to water ski? troll around your local lake? etc). To find the best "bang for your buck" please consult your local dealer and discuss your needs with him/her. They will be more than happy to help you find the best outboard for your particular needs.
As with trying to choose the right horsepower, choosing the right propeller to fit your needs requires you to take a number of factors into account. We have put together a detailed section regarding propellers to help you determine which is the best prop for the job. Please bear in mind that there is no one magic answer that will absolutely guarantee that the prop you choose will give you the performance you expect; sometimes it's simply a matter of trying different props to determine which one will work best for your particular application.
Tohatsu 2-stroke outboards require a 50:1 (20mL of oil for each litre of petrol)
For your 2-stroke outboard, be sure and use only 2-cycle outboard oil, with an NMMA (National Marine Manufacturers Association) certified rating of TCW3. Never, never, never use automobile oil in your 2-stroke outboard. You can find Tohatsu 2-stroke outboard motor oil at your local dealer.
TLDI outboards should only be run using an oil that meets or exceeds TCW3 oil specifically formulated for use in Direct Injection motors and are semi-synthetic or full synthetic. Standard TCW3 oil is not recommended for use in TLDI outboards.
For your 4-stroke outboard, you should use Genuine Tohatsu FC-W 4-Cycle Oil. Tohatsu FC-W 4-Cycle Oil is NMMA Certified and has been specially formulated to handle the higher RPM's that outboards are subjected to, as well as special rust inhibitors to combat the harsh operating conditions of the marine environment. Genuine Tohatsu Oil reduces friction & wear and ensures the internal components are properly lubricated for optimum performance. If Tohatsu 4-Cycle Oil is not available we recommend using an NMMA Certified FC-W 4-cycle oil formulated for use in outboard engines. Look for oils bearing the FC-W trademark.
Your Tohatsu 4-stroke outboard is equipped with an Engine Oil Warning Lamp (except for 2hp, 2.5hp & 3.5hp). When the warning lamp is off, it indicates that sufficient oil pressure is present. If the warning lamp is on (red light is on) or blinking on/off, immediately shut down your outboard and check the oil level. Replenish as needed. If the oil level is at the appropriate level and the light continues to stay on or blink, consult your local distributor for assistance (do not use your outboard until a distributor has corrected the problem).
You may notice the engine oil warning lamp come on when you first start your outboard. This is normal and should go off after a few seconds. On cold starts, the lamp may stay on longer due to the oil being thicker. If so, stop the engine and restart and the lamp should go off quickly. If the warning lamp does not go out after 4-8 seconds, stop the engine and consult your local distributor.
The octane rating for Tohatsu outboards are 91 (RON) or 87 ((R+M)/2).
Tohatsu outboards are formulated to use E0-10 ethanol fuels only.
Any fuel with an ethanol content above E10 is prohibited and could lead to issues.
Immediately shut down your outboard! Do not start your engine back up until the problem is corrected or you will overheat and severely damage your engine. First check that the telltale is not stopped up (using a wire or air pressure) and then check the water intake on your lower unit and make sure that it is unobstructed. If the water intake is clear then chances are your water pump impeller needs to be replaced or you have an obstruction inside your lower unit. Take your outboard to your nearest dealer for inspection.
You should inspect your water pump impeller each year before taking your boat out on the water. We recommend you change your impeller every year at a minimum depending on the amount of use you put on your outboard. One thing to remember is that even if you only use your outboard a couple of times a year you still need to have your impeller checked/replaced every year. Water pump impellers are made from rubber and will deteriorate over time even without being used (commonly referred to as "dry rot"); this can be just as damaging to your water pump as wear and tear.
When used in salt water we also recommend you lubricate the driveshaft splines and hardware while changing your water pump and the lower unit has been removed. This greatly reduces problems from salt corrosion on shaft splines and installation hardware.
Measure from the top of your transom to the bottom of your keel. If it is from 15" to 17" long you'll need to get a Tohatsu outboard with a "short" shaft. If it is from 20" to 22" long you'll need our "long" shaft outboard. Tohatsu outboard shafts are measured from the bottom of the engine mounting bracket to the cavitation plate on the lower unit. Generally most boats need either a short or long shaft although some boats require a 25" shaft (ultra-long shaft) outboard.
Please note that depending on the particular model, some Tohatsu shaft lengths may be 2" longer than "standard" (ie: a short shaft may be 17" instead of 15" and a long shaft may be 22" instead of 20"). Therefore, depending on the configuration of your keel, the shaft length required by your boat may be different than the above recommendation. We recommend that you consult with your local distributor to determine which is the correct shaft length for your particular boat.
Please ask your nearest dealer
Please refer to your owners manual