Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  Yamaha Z250 Malaise

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Yamaha Z250 Malaise
phoeker posted 06-29-2003 12:19 PM ET (US)   Profile for phoeker   Send Email to phoeker  
Hello to All in Whalerland,

Finished up restoration on my 1992 Walkaround and with great anticipation took her down to the local dealer for rigging of a new Yamaha Z250 HPDI (along with 9.9 kicker).

That was about a month ago.

Now, with only six hours on the motor, I'm waiting for yet another four-day transit of supposed fix-it parts. All on the verge of one of the year's biggest holiday / boating weekends.

Here's the situation:

Voltage readings on the gauge at idle are 13.8. When RPMs increase through all ranges, voltage readings decrease significantly to less than 12 @ WOT, causing the motor to cut out. This motor, with two, (maybe three?)fuel pumps requires vast amounts of battery power, so much so that I'm using a series 31 battery.

The first two fixes: replace ignition coil, and voltage regulator, failed. Now the service reps are telling us to replace the stator, which we'll do this week. If I said I was confident this third replacement would fix the problem I'd be lying.

At this point I have a brand new $15,000 motor that has been taken apart twice to repair a problem that should never have happened, and a third operation is scheduled this week.

This is my fifth Yamaha in the last decade so my expectations were extremely high. Now I may caution others to let new technology ripen on the vine a bit before buying the promise of "innovation & reliability".

Capt. Phil Hoeker
McAllen, TX

Jamie 20 outrage posted 06-30-2003 01:14 AM ET (US)     Profile for Jamie 20 outrage  Send Email to Jamie 20 outrage     
Assuming that your mechanics are working in conjunction with Yamaha tech guys over the phone, I would say that they are doing the best for you that they can. If they aren't on the phone, then you need to find a more modern dealership. You are right about being leary of new technology outboards. Remember, the outboard companies are forced into this and if Yamaha doesnt have the best patents, then they have to work in their own direction. Meanwhile, your standard outboard mechanic is asked to do alot more than was required a few years ago. Plus some service manuals really are poor. My mechanic friends tell me Yamaha manuals are lacking.
zx29b posted 06-30-2003 08:56 AM ET (US)     Profile for zx29b  Send Email to zx29b     
"never buy the first year of anything"
my engineer father
PMUCCIOLO posted 07-08-2003 09:26 AM ET (US)     Profile for PMUCCIOLO    
Capt. Phil,

Do you have an update for us on your 250 HPDI?

phoeker posted 07-09-2003 10:46 AM ET (US)     Profile for phoeker  Send Email to phoeker     

Yes, I do have an update.

We replaced the stator and added a lock washer to the motor's negative power lead. This fixed the high speed cutouts and steadied the voltage readings, but I'm still not certain the charging system is performing as designed.

At idle the voltage readings are 13.8 - 14. At speed throughout the RPM range, voltage readings drop to 13.4 - 13.6 indicating that the battery is getting a better charge @ idle, just the opposite of what should be happening.

My last motor, a Yamaha 225 EFI, showed 12.8 volts @ idle and increased to 14.2 volts @ WOT.

Yamaha tech says the voltage readings are acceptible and fall within spec, but I'm not certain the charging system is performing as designed, and in fact sent another email this morning reiterating this point.

Other than this charging snafu, the motor is superb. Originally designed for twin outboards, my 1992 23 Walkaround, 4050lbs, (w/o bracket) performs nicely with this powerplant.

Top speed fully loaded: 39 MPH @ 5200 RPMs
Cruising speed: 25-29 MPH @ 3700-4100 RPMs
Fuel efficiency: Optimum, 27 MPH, 9GPH= 3MPG+/
Time to plane: 4 seconds

All-in-all a good setup, but I'll be much happier to get the charging system running the way I think it should be.

phoeker posted 07-09-2003 12:06 PM ET (US)     Profile for phoeker  Send Email to phoeker     

Yamaha tech rep just called and assured me that the charging system is functioning properly. He explained that the 1000PSI fuel injection system utilizes two fuel pumps requiring a lot of battery power. Some of the power produced by the stator is diverted from the batteries to help run the motor, therefore the voltage readings will read slightly lower than a conventional EFI/DFI motor.

I think I'm in business.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.