06 Tracker 175 60hp 4 stroke

I bought this boat about 2 months ago and I've had it on the lake 6 or 7 times. Previous to my last trip the boat has ran great and I've not had a problem with it. But last Sunday I went after church and the boat wouldn't reach it's top speed with the throttle all the way down. The boat was running anywhere from 10 to 20 mph slower than normal with only reaching 4000 rpm's compared to normally reaching 6000 rpm's. I'm just wondering if anyone else has had this prob with their motor.

I had this same problem on a 115 merc opti, brought it in to tracker service and it was the coil that had burned out. Apparently this caused only 2 of the 3 cyclinders to fire. 

I had this same problem on a 115 merc opti, brought it in to tracker service and it was the coil that had burned out. Apparently this caused only 2 of the 3 cyclinders to fire.

I was thinking coil or spark plug too but what was throwing me off is that the motor is running just as smooth as it was a week ago. And I know when a car/truck has a bad coil the engine runs rough.

My guess is a fouled plug or a weak and collapsed fuel line. Or perhaps the throttle linkage slipped at the motor.

How about a bilge full of water? Extra weight will rob RPMs and speed.

Same thing happened a few years back to my 06' 25hp Merc 4-stroke. BAD GAS. Drain the floats on the carbs, get rid of the gas in the tank, put a new fuel filter in, change the plugs, and fill her up with 93 octane treated with a full blast of seafoam and star-tron. Let it run through the system for a while, and then take it to the water and  open her up. I also changed all my fuel lines and primer bulb too. All of that was cheap and easy, and if that doesn't work for you, you have at least eliminated all the cheap easy stuff as the cause of the problem.

Yea the boat had no extra weight or water and I've only put pure gas/ethanol free gas but ill try the high octane gas. And I'm going to try and do plugs this week because it wouldn't hurt and I'm not sure when the previous owner had it tuned up. Thanks for yalls info, hopefully she'll be back to normal by Sunday

Do you have the option to put it to throttle only and see if will spin up to the full 6000rpms?

Do you have the option to put it to throttle only and see if will spin up to the full 6000rpms?

 

Not recommended without a load on the motor.

I had no idea about the engine needing to be under load.. I learn something new every day.

in the early 4 stroke they had a bunch blow.

 

I have friends that had the exact motor/boat you are speaking of and they popped a motor.

I cant remember the year model they had though .

It sounds like, for some reason you have lost a cylinder.  This could any of a whole host of things, from bad electronics to a bad engine.

 

First thing I would do it pull all four spark plugs and see if they all look alike.  If one is black and wet, it's foulded for some reason.  Swap it out for a new one and see how it does. 

 

From there you would want to check the spark with a tester.  It should jump a 7/16" gap with a nice blue spark.   One thing to remember, most plug wires may work fine and show plenty of spark, but when you put the engine under a heavy load, they can start breaking down, so the only way to check one for sure is to replace it.

 

If it was me, while I was checking the plugs, I would go ahead and do a compression test.  All cylinders should be within about 5% of each other.

 

I would also Flush the fuel system and change the filter.

 

Unless you are very, very mechanical, this is about as far as you can go in your driveway.  It plugs/wires didn't fix the problem and the compression is good, anything else is going to be beyound what you can do.   Most anything else is going to require the computer diagnostics and special equipment. 

 

It could be a bad injector, SECM and a number of other things you have no way of knowing or testing.  

 

OH! one other thing, NO WAY IN H**L should you try and rev that motor to 6,000 rpm without it being under a load.  Also, even reving one to 2,000 or 3,000 means nothing if it's not loaded.  All it's doing is running off a little extra spark advance so you are not getting into the fuel system like it would if it was loaded.

I believe I got some bad gas. I normally full up at the same gas station but it hit me today that 3 weekends ago I went to a new lake and filled up at near by gas station. So fingers crossed tomorrow with some high octane gas and fuel cleaner I blow it out.

If it had water in the fuel you may need to dump the water from the filter cup.

It sounds like, for some reason you have lost a cylinder.  This could any of a whole host of things, from bad electronics to a bad engine.

 

First thing I would do it pull all four spark plugs and see if they all look alike.  If one is black and wet, it's foulded for some reason.  Swap it out for a new one and see how it does. 

 

From there you would want to check the spark with a tester.  It should jump a 7/16" gap with a nice blue spark.   One thing to remember, most plug wires may work fine and show plenty of spark, but when you put the engine under a heavy load, they can start breaking down, so the only way to check one for sure is to replace it.

 

If it was me, while I was checking the plugs, I would go ahead and do a compression test.  All cylinders should be within about 5% of each other.

 

I would also Flush the fuel system and change the filter.

 

Unless you are very, very mechanical, this is about as far as you can go in your driveway.  It plugs/wires didn't fix the problem and the compression is good, anything else is going to be beyound what you can do.   Most anything else is going to require the computer diagnostics and special equipment. 

 

It could be a bad injector, SECM and a number of other things you have no way of knowing or testing.

I think after the lake tomorrow if the fuel treatment doesn't work then I'm going to swap out the plugs. Thanks for the info one the wires never thought about them performing differently under a load.

If you think it's the gas, change the seperator/filter.  Water in the gas is what causes a problem, just adding high octane is not going to do anything for you and adding an additive is not going to do anything for what has been trapped in the seperator/filter

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If you think it's the gas, change the seperator/filter.  Water in the gas is what causes a problem, just adding high octane is not going to do anything for you and adding an additive is not going to do anything for what has been trapped in the seperator/filter

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I'll go ahead and do that too. If you get any of your parts online, what website do you use