Yamaha 200 HPDI Problems

[Cregeis1]

My daughter bought a used boat with a Yamaha 200HP HPDI in February and has constantly had problems with the engine losing power. Her local marina mechanic has changed the thermostats, replaced the gaskets to the low pressure pumps and adjusted the cables. Each time he fixes something, the boat initially runs well but then develops problems. The motor sat for a while before she bought it and the engine has relation hours for a 2000 model.

She is getting very frustrated and starting to think she made a huge mistake buying an old boat. She just graduated from NC State last May and used most of her savings buying the boat.

As her father, I hate to think that each time she takes the boat out, she may get stranded.

Can a mechanic go through this engine throughly and replace whatever needs to be replaced and then expect this engine to be reliable again? Or is it just a matter of fixing things as they go bad? Or should she just buy a used 4 stroke engine?

I really appreciate your your advice!

Thanks, Chris

[99yam40]

hard to help without knowing what is wrong with a motor

[zenoahphobic]

hard to help without knowing what is wrong with a motor

If I understand it correctly, it is running fine at the moment.
It is hard to believe the three different things were all fixes for loosing power. If the thermostats were responsible then overheating seizing the engine would do it. Same, loss of fuel pressure would do it. And a loosening throttle cable would do it by not being able to get WOT.

But all three after one and other causing this loss of power.......unlikely. A decent diagnosis is needed. I'm inclined to think fuel blockage, I'd look carefully at the injectors.

I would not think why a second hand fourstroke would fare any better, there is more to go wrong.

[zenoahphobic]

If any outboard has been sitting for a while, the entire fuel system should be gone through...filters, hoses replaced; fuel tank drained and cleaned. And as stated previously the injectors should be cleaned and tested if not completely replaced.
Of course there are many other maintainance things to do. Time consuming and probably costly for a highly qualified mechanic to do.

[99yam40]

find a yamaha shop with a master tech working there to have a look at the rig.
Rodbolt17 is a master and is located in NC, but have no idea where the boat is located.

Bad gas/water (layered) or other stuff in the tank that gets stirred up when taken out on the water, could be the problem if screens/filters are getting plugged.

sucking air into fuel system starving the motor for fuel or maybe a bad connection that shows up in rough water( boat pounding) might also be a problem.

hard to say since we have no idea what has been happening.

Hooking the motor up to a computer and running it to see what is going on when the problem shows up is needed.

[boscoe99]

If I understand it correctly, it is running fine at the moment.
It is hard to believe the three different things were all fixes for loosing power. If the thermostats were responsible then overheating seizing the engine would do it. Same, loss of fuel pressure would do it. And a loosening throttle cable would do it by not being able to get WOT.

But all three after one and other causing this loss of power.......unlikely. A decent diagnosis is needed. I'm inclined to think fuel blockage, I'd look carefully at the injectors.

I would not think why a second hand fourstroke would fare any better, there is more to go wrong.

The complexity of an HPDI is about on par with a four stroke IMO. Five (5) fuel pumps, HP fuel pump driver, two fuel injector drivers, 750/1000 psi fuel injectors, multiple cylinder operation, etc.. seem to be every bit as problematic as a common four stroke.

[Cregeis1]

If I understand it correctly, it is running fine at the moment.
It is hard to believe the three different things were all fixes for loosing power. If the thermostats were responsible then overheating seizing the engine would do it. Same, loss of fuel pressure would do it. And a loosening throttle cable would do it by not being able to get WOT.

But all three after one and other causing this loss of power.......unlikely. A decent diagnosis is needed. I'm inclined to think fuel blockage, I'd look carefully at the injectors.

I would not think why a second hand fourstroke would fare any better, there is more to go wrong.

No, the boat is not running well at the present time. She took the boat out after work yesterday and the boat couldn't get on plane. She had the boat out just a few days before and it was fine. Every time it has a problem, the mechanic looks at it and made the previously mentioned fixes and the boat would run fine for a while but then develop the same power loss.

[Cregeis1]

If any outboard has been sitting for a while, the entire fuel system should be gone through...filters, hoses replaced; fuel tank drained and cleaned. And as stated previously the injectors should be cleaned and tested if not completely replaced.
Of course there are many other maintainance things to do. Time consuming and probably costly for a highly qualified mechanic to do.

I think you are right, the same issue keeps pooping up so we need to completely go through the engine one time and do what you said to do. I would rather do it all at once than to constantly have problems which is very disheartening. She is almost at the point of just selling it.

[Cregeis1]

find a yamaha shop with a master tech working there to have a look at the rig.
Rodbolt17 is a master and is located in NC, but have no idea where the boat is located.

Bad gas/water (layered) or other stuff in the tank that gets stirred up when taken out on the water, could be the problem if screens/filters are getting plugged.

sucking air into fuel system starving the motor for fuel or maybe a bad connection that shows up in rough water( boat pounding) might also be a problem.

hard to say since we have no idea what has been happening.

Hooking the motor up to a computer and running it to see what is going on when the problem shows up is needed.

We are at the point that we would trailer it to Japan and have Yamaha look at it!!! Do you know how to get in touch with Rodbolt17 so I can see if he would be willing to work on it?

[99yam40]

he does not do PMs so post you are wanting him to have a look at it and hope he will respond soon.

Someone might find the phone of where he works is all else fails

[FabricGATOR]

No, the boat is not running well at the present time. She took the boat out after work yesterday and the boat couldn't get on plane. She had the boat out just a few days before and it was fine. Every time it has a problem, the mechanic looks at it and made the previously mentioned fixes and the boat would run fine for a while but then develop the same power loss.

Yes, I would get a second opinion.

Joe's Marine Service, Wanchese, NC

[Operaman]

To rule out bad fuel in the tank of the boat, run with an portable tank, by passing the tank on the boat with fresh fuel.

[pstephens46]

We are at the point that we would trailer it to Japan and have Yamaha look at it!!! Do you know how to get in touch with Rodbolt17 so I can see if he would be willing to work on it?

Rodbolt is Tom Beachum. Hope I spelled his last name correctly. Joe’s Marine as we discussed.

[FabricGATOR]

When your daughters vessel gets all squared away, please return and describe the fault found and the cure.
Your feedback makes the forum archive complete and helps us to help others.
That, and it is a form of closure.
Cheers!

[Cregeis1]

When your daughters vessel gets all squared away, please return and describe the fault found and the cure.
Your feedback makes the forum archive complete and helps us to help others.
That, and it is a form of closure.
Cheers!

Thanks! I definitely will let everyone know.