Force Outboards

June 14, 2003

See the options to the left (winter storage, gearcase oil) for some how-to articles.

The motor that came with our Bayliner 1902 Capri boat is a 1989 US Marine Force 125hp outboard as shown in the picture above but the gearcase and engine cover are from a newer 120hp Force outboard.

These motors were originally Chrysler units. When Chrysler decided to get out of the outboard motor business, Bayliner boat them out and started the US Marine Force brand which was bought by Mercury Marine sometime in the 90's and most of the later models share a few Mercury bits and pieces. Replacement parts come backed as Mercury Quicksilver.

The Force outboards aren't the best but they are quite reliable and I haven't had too many problems with our's except for rotting away engine/transom brackets. I replaced mine with some used ones a few years ago. I do find the motor brackets pretty damn wimpy on such a large engine. I wouldn't be surprised if a few of these motors had engine bracket failures and dropped to the bottom.

So... watch out for salt corrosion and replace parts as necessary.

I've heard a few problems with the power heads in 150hp variations but I think the 120-125hp motors faired ok.

Make sure you replace your zink anodes every 3-5 years depending on wear. It's better that the salt water eats the zink than your motor!

About 5 years ago I bought a couple of 4-blade props from Solas propellors. Some say their props are a bit thin and cheap but I haven't had any troubles with them aside from hitting logs. The best one was when one blade completely snapped off on a log... poor prop! I bought them from Canada Propeller but they went out of business many years ago, actually about a year after I bought them. Bad management I guess.

I do find that the 4 blade props offer much smoother running than typical 3 blade props reducing engine vibration and probably lessening the shock load on your outboard's gearcase.

If you run in salt water I would recommend you stay with aluminum props as hitting a log with a stainless prop could severely damage your gearcase because stainless doesn't bend easily on solid objects.

I always make sure I have at least 50:1 gas/oil mixture in the fuel tank. Even a bit less (more oil) is ok and better for your motor. When mixing the fuel I always add 500ml of 2-stroke oil with 25L of 91 octane of better grade fuel. Get a couple of 5gal jerry cans and each is 25L so easy to measure. Otherwise note how many liters you use at the fuel pump and add oil accordingly. Of course newer engines use oil injection or don't need oil as is the case with the newer 4-stroke outboards which are essentially car engines turned on end.

With our 125hp Force outboard I've had to replace the ignition coil packs once. I lost power all of a sudden and it felt like it was running on 2 or 3 out of 4 cylinders. That's what the symptoms are when the coil packs go out. Just limp it back to the dock if you can or have your boat towed.

Sometimes it's simply an ignition wire that has slipped off a spark plug. Let the motor idle while on the water if you run into problems with smooth engine operation and lift off the engine cover. If you see a wire has come off a spark plug shut it off and replace the wire. Otherwise keep it running and head for the nearest dock to assess the damage or repairs needed. It could be very difficult to get it started again if you turn it off depending on what the problem is.

Use your hand and feel the engine cooling water coming out of the two ports just below the engine cover on the rear of the motor leg. It should be warm to the touch not super hot. If it's super hot shut down the motor and lift up the motor leg (tilt). Sometimes you can get a plastic shopping bag in the water that wraps itself around the motor leg and obstructs the cooling water intake under the waterline.

If you don't have that problem it could be your water pump impellor is in need of replacing. Try to limp it back to the dock to make the necessary repairs.

Most of the time, if you have a hard starting condition it can be your electrical system. Every once in a while remove your power cables from the battery and using some sand paper or steel wool cleanup the terminals. Fasten them very tight and use some silicone spray or silicone gel to keep things from corroding. Salt water is deadly stuff! Sometimes I thought I had a flat battery but it was a bad connection on the electrical wires.

That's all for now, more about Force outboards later.