subject: Outboard Engine Test New Mariner And Tohatsu 4hp F4m Mfs4c Part 1 [print this page] So its finally here - the all new F4M from mariner outboards and mercury marine, designed and manufactured by tohatsu outboards, the most popular inflatable boat engine of the past decade. This has been a long time coming as the original 4hp 4 stroke from this stable launched back in 98 has stood the test of time and been a most reliable little motor, and of all the outboards for sale in this hp range it has been the most popular with the purchasing public.
The all new C model boasts the following extra features:
Industry first - front mount gearshift in 4hp
Longer tiller
Larger front and rear carry handles
Fuel cap at front for easier re-fueling
Re-designed induction system to reduce noise
So will these points win through in a test? Well here goes! For this test I used the engine in Mariner livery, but the mariner, mercury and tohatsu outboards are all identical, on un-boxing the Mariner F4M the new engine looks almost identical to the old model, the only exterior differences are the new hood styling with the filler cap at the front, the longer tiller - boy it is long, not sure if that will be well received by all except for those wishing to keep the nose down on their inflatable boat - but more on that in a minute, the new carry handle on the front and bigger grip on the rear, and of course the front mount gearshift, which Im sure is a real positive, again ideal for the inflatable boat fraternity, and these outboards for sale will do well just on this point alone - look out for other manufacturers jumping on this band-wagon in the very near future.
I quickly went through the PDI, and during this process whilst the cowling was off for greasing all moving parts I had a good look at the induction system, it looks exactly the same to me....
After the PDI was done I decided to bed the engine in before the test, so it went into our purpose built engine test tank, was filled with fuel and started, now 4 stroke single cylinder engines with integral fuel tank (no matter which make) all have one thing in common, the carburettor is on top of the cylinder head, which means that unless your fuel level is brimmed right to the top the carb can not be gravity fed as the carb level is higher than the tank fuel level, this means priming the carb with the fuel pump, done by pulling the engine over 10 to 15 times on the pull cord. This is a major flaw and if any manufacturer wants to improve the design of their small 4 stroke this is where I would look first!! ...... Continued in my first blog ......
