new boat... how to know if the motor is ok? - TEST RESULTS

[CharlestonMako]

I am considering a new boat, but am wondering how I can be sure the motor is in good shape? Its out of town, and I really don't know much about outboards. Is it reasonable to ask someone to let you take it by a local mechanic to give it a look over... or can an outboard mechanic even tell if there is a hidden problem?

Will going for a sea trial and seeing that it performs well be enough?

BTW: its a 2004 150 Yamaha 4 stroke (I know nothing about these motors... been using a '88 140 Johnson for 3 yrs). the guy says 225 hours, but he's guessing as he dosent have an hour meter... just dont want to make a huge mistake.

Ive heard its a good motor though, right?

Thanks,

 

[JB]

Re: new boat... how to know if the motor is ok?

Re: new boat... how to know if the motor is ok?

The absolute best way to evaluate a possible purchase is a thorough sea trial. You are on the right track.

Good luck.

 

[CharlestonMako]

Re: new boat... how to know if the motor is ok?

Re: new boat... how to know if the motor is ok?

So as long as it runs ok on the sea trial it should be alright? Starts up fine, runs at right RPM at WOT (about 6k right for a yamaha?), and dosent cut off on us? anything else? how do these motors **** coolant water?

Man, it seems like a little more definitive diagnostic would be in order before I drop the biggest chunk of cash I've spent since I bought my house. Can a Yamaha tech check the computer for a "check engine light" or something? Play me like I'm an idiot... I dont know a thing about newer 4 strokes.


Thanks a lot

 

[99yam40]

Re: new boat... how to know if the motor is ok?

Re: new boat... how to know if the motor is ok?

A check out by a trusted Yamaha guy is not a bad idea, It may cast you a little but they should be able to tell you a lot about the motor.
Not positive on that one but think they maybe able to tell how it has been run and how long on some motors. computors.

 

[clubchuck]

Re: new boat... how to know if the motor is ok?

Re: new boat... how to know if the motor is ok?

Your best bet is a combination of sea trial and some very basic checks like
Compression- each cylinder
Fuel lines for cracks or soft places
electrical lines for cracks, burns or frays
lower unit grease - no water present
corrosion around trim motor
Shift cables operate smoothly
and just a visual review of the engine itself.

You can suggest a shop test by a certified Yammy mech.
A friend of mine once said there are only two kinds of outboards, those that are running and those that are not....... Good luck

 

[boatguy823]

Re: new boat... how to know if the motor is ok?

Re: new boat... how to know if the motor is ok?

this is what we look at/for at our dealership:

1. We will connect the laptop to check for any active faults from sensors as well as stored faults; we look at the rpm profile which will show the amount of time at given rpms, we also get exact engine hours (given that the ecu has not been replaced).

2. Don't bother with the compression test..have a leakdown test done it will show if there are problems with valves, rings or head gasket.

3. Drain and pressure/vacuum test the lower unit looking for signs of water and/or metal shavings.

4. Check the crankcase oil , is it diluted or overfull could indicate cooling problems or incorrect propping.

5. Check fuel system for leaks,filters clean, signs of water and/or debris.

6. We run the engine listening for any obvious noises (balancer assmbly is a very common problem on these engines) we'll water test it as well to check how it runs at different rpms.

7. Check the water flow from the teltale; good pressure and not hot

8. We check tnt system, engine wiring overall condition,salt water use etc...

I would suggest you take it to a yamaha dealer with factory trained techs for an evaluation its simple enough to do and should only take about an hour or so and if all components (fuel,compression, and ignition) are working the way they were designed to work then you have a good engine.

 

[CharlestonMako]

Re: new boat... how to know if the motor is ok?

Re: new boat... how to know if the motor is ok?

Thanks guys... I scheduled an appointment for a leakdown test, etc from a Yamaha dealership. They will email the results to me this week, and if all is well, I'll be heading up to sea trial it in a week or two.

Thanks

 

[CharlestonMako]

Re: new boat... how to know if the motor is ok -- 4/14 - test results

Re: new boat... how to know if the motor is ok -- 4/14 - test results

So I had a 2 hr test done... first hour was compression, leak down and lower unit oil check., second our was on the computer.

compression was 195 on all four (this is a 4 cylinder? I thought was 6)... is that normal? im used to 120lbs being normal.
leakdown was 7%, 7%, 8%, 8% (don't know what this test is... is that good? they said is was fine)

said engine oil and gear oil is clean, engine is clean with no corrosion. the anodes will need to be replaced soon, and the balancer is making a noise. Ive read this is common on these motors?

Yamaha agreed to pay parts and labor to replace balancer (whatever that is)... so I scheduled that... does that mean it should be good to go?

oh yeah... hours are 376. for 5 year old motor how does that sound? how many hours can you usually get out of these motors?

 

[boatguy823]

Re: new boat... how to know if the motor is ok? - TEST RESULTS

Compression and leakdown numbers all look good ...yes 195 is pretty normal. Leakdown numbers are within specifications

Everything you have stated sounds good so depending on cost jump on it. As far as the amount of hours.........not bad in my opinion. With the proper maintenance and care this thing will last a long time.

I would suggest water pump and t-stat replacement unless you know exactly when they were last replaced and they should be done every 2-3 years.

Also before I forget.....timing belt should be replaced every 1000 hours OR 5 years but it is NOT a major deal to have done.

Anyways thats my two cents for what it's worth. I think you will be satisfied with it if you buy it. Good luck.

 

[CharlestonMako]

Re: new boat... how to know if the motor is ok? - TEST RESULTS

Thanks. timing belt huh? being 5 years old I guess I should do that. Can you guys give me a ballpark price for getting the lower unit oil and water pump, T-stats and timing belt replaced by a yamaha dealer?

I mean.. is this $1000 worth of work or what? I sure hope not! It might help me with negotiating for the boat.

If the timing belt breaks will it ruin the motor, or just leave me stranded until I get it replaced? can it be inspected for wear as opposed to a preventative replacement?

Thanks!

 

[boatguy823]

Re: new boat... how to know if the motor is ok? - TEST RESULTS

cost depends on shop rate where you have the work done as far as labor goes but water pump,t-stat, and timing belt can be done in less than two hours. As far as cost of parts not really sure but probably around 200 bucks or so....work a deal with the seller...maybe split the cost. and yes if the timing belt goes so does the engine. pistons and valves will collide.