"Del Cecchi" wrote in message
...
Yamaha problems? Are they having HPDI problems? The information is still
not reaching the general public. There was just a 300 HPDI article in
Bass and Walleye boats, and I don't recall so much as a hint of any
problems.


Like the '98-'99 FICHT problems, the Yamaha 300 problems only affect certain
applications, mostly offshore fishing boats. It does not affect the
freshwater bass boat motors. Part of the problem is salt water intrusion,
but the "fix" takes 12 to 15 hours to do, and it is a whole series of
changes, including wiring harness, ECU, adding a reverse switch, etc. and
can only be done by factory approved locations. They are not fixing all at
this time, just the offshore folks on certain makes of boats. You can read
all about it and some horror stories (as usual) on various web sites and
forum. It is also known in the trade journals. Use Google.




FOR 2000, the FICHT system was improved quite a bit and called FICHT
Ram, and really did well. It was quieter and smoother than the earlier
series, and was better on fuel use. In 2001 they came out with a new
block, the 3.3L and it is still used today, and that really made the
motors perform even better while the hp increased to 250. These
versions are still being produced today.

So what did they change? As an engineer I am interested in stuff like
that.


The combustion process at 15% power was changed so all cylinders did not
switch over from stratified to homogenous mode all at once. This smoothed
the engine operation in that range (while the boat is plowing, and not on
plane yet) and cut down on the sooting of the rings which caused most of the
engine problems. There was a lot written about the re-engineered FICHTS and
the new EMM's that replaced older ECU's, 40 volt systems vs. 24volts,
exhaust pressure sensors, etc. Look for back issues of various boating
magazines in the library or do a lot of searching with Google. There was a
lot of information put out back then. An Australian boating magazine had a
very good article about the technical changes, but of course Karen didn't
believe any of it.

Bill Grannis
service manager