Mercury 175 sport jet

[Tylorwashere]

I'm currently looking (very hard, might I add) at a 98 tango that has this motor. However, a quick Google search comes up with people having just tons of problems with this motor. Now I know nobody is going to come singing praises for something, they are obviously only going to ask questions when something is wrong, but should I be wary?

Also, he said he just had to replace the stator, does this motor have the regulator/rectifier as one unit? Could the stator going have caused any damage to it?

 

[Speedling]

There are lots of problems... but totally fixable.
Look for a parts schematic.
Sorry i don't know the motor myself.

 

[Ronnie]

My first jet boat had this motor. I had to have all three carbs rebuilt and retuned the because the needles were deteriorating. The suspected cause was the new fuel formulations at the time. The total cost for parts and labor was around $700 if I had to do it again I would have tried to do it myself to save on labor costs but tuning / synching multiple carbs had me concerned. Other than that the engine never gave me any problems. I don't know about the rectifier but if it's like the ones on modern Yamaha engines they are less than $100 so I would just replace it as a maintenance item on a used boat. One other thing, the spark plugs are different for that engine, the tops are flat / no resistor part arches over from the side to the center.

I'm familiar with the tango, it was a little bigger and heavier than my boat but would still accelerate well, like a PWC from that period and had a top speed of at least 45 mph. Good luck with whatever you decide to buy if anything.

 

[Tylorwashere]

My first jet boat had this motor. I had to have all three carbs rebuilt and retuned the because the needles were deteriorating. The suspected cause was the new fuel formulations at the time. The total cost for parts and labor was around $700 if I had to do it again I would have tried to do it myself to save on labor costs but tuning / synching multiple carbs had me concerned. Other than that the engine never gave me any problems. I don't know about the rectifier but if it's like the ones on modern Yamaha engines they are less than $100 so I would just replace it as a maintenance item on a used boat. One other thing, the spark plugs are different for that engine, the tops are flat / no resistor part arches over from the side to the center.

I'm familiar with the tango, it was a little bigger and heavier than my boat but would still accelerate well, like a PWC from that period and had a top speed of at least 45 mph. Good luck with whatever you decide to buy if anything.

How did you know the needles were deteriorating? Just losing power so you checked?

 

[Ronnie]

It became more difficult to start and eventually it wouldn't start at all so I brought it in to a local boat repair shop for inspection. When they discovered the problem they recommended that the carbs be rebuilt. The rebuild kits were about $65 each (x 3 for the number of carbs) the remaning costs were all labor.

The shop also showed me the needles, it looked like they were made of layered metal (when in fact they were solid) and parts of some of the layers were chipped away / missing. The best analogy I can think of is an onion which is not uniformly peeled. The shop told me that they had never seen this before so called Mercury about it and even sent the needles in to Mercury for inspection, I don't know what mercury's response was if any.

Anyway, the boat ran like it was new after the carbs were rebuilt and I never had issues with any other part of the motor. I did have to replace the bellows that sealed the steering rod connections but that was more of a maintenance item since they were made of rubber and exposed to direct sunlight for years (I stored the boat on the side of my house and the cover didn't protect the bellows which ar outside the hull). If the bellows are cracked/leaking they leak is directly into the boat where the streering rods exit the hull.

In writing this I recall the the boat I had afterwards had a 240 hp Mercury sport jet which was fuel injected. It developed a hard starting issue as well. I knew it couldn't be the carbs since it had none. I suspected the stator or starter but never found out what the problem was because the boat was stolen the night before I was supposed to bring it into the shop but that is another story.

If the tango you are looking at is hard to start and you suspect it's the carbs it may still be worth buying as long as the price reflects the repair costs. Carb rebuild kits, bellows, etc. are easy to find/readily available through Mercury (not sure about staters and / or starters). I'd be more concerned about parts availability for the boat itself. Sugar sand (in my case euroline and seadoo) stopped making boats years ago.

 

[Ronnie]

I forgot to mention that for the most part both of my boats would start in the trailer but not in the water with a load on the impeller so test drive it, don't just run it and/or do a compression check while it is on the trsiler.

 

[Tylorwashere]

I forgot to mention that for the most part both of my boats would start in the trailer but not in the water with a load on the impeller so test drive it, don't just run it and/or do a compression check while it is on the trsiler.

Your boat got stolen? That's pretty crazy. I was definitely going to have him meet me at a boat launch before I bought it though. I'm collecting enough ammo right now to talk this guy down a lot lol.

 

[Diplomasta]

These are great because they are an outboard powerhead. Much easier to work on than a horizontal jet engine. All you gotta worry about are the things made of rubber. Carb gaskets, fuel pump, cable bellows, fuel lines, etc. The autostart enrichner is a little over the top, but you CAN convert it to a push button primer. The ecu that runs the enrichner (tks) is expensive af, if you can find one. Beyond that, just make sure the oil stays inside the drive. It has gear oil in the fwd gearbox (flat head screws on the bottom of boat, fill from center one like a regular gearcase). And also the jet pump oil in the rear behind the impeller. Use jet pump oil in that one.
Be aware, some models only cool the exhaust when running on a water hose. Not the engine. So don't run for too long on the trailer unless you're dipped in the river. ?
Keep up with the maintenance and stay ahead of any corrosion, and you'll love your jet boat.