View Single Post
  #6   Report Post  
posted to rec.boats
HK HK is offline
external usenet poster
 
First recorded activity by BoatBanter: May 2007
Posts: 13,347
Default Yamaha F150 break-in

wrote:
On Thu, 12 Mar 2009 20:47:58 -0400, DK wrote:

wrote:
I am about to purchase a Hydra-Sports 202DC with a Yamaha F150 4
stroke.
I have read the beak-in procedure.
1hr at 2000 rpm , 1hr at 3000 and the next 8 hrs no full throttle for
more than 5 mins.

My question is; When pre-purchase water testing, how much or little
damage is sustained while the sales guy or I run a new motor at full
throttle for a few minutes to see full speed and other handling
characteristics of the boat

None. A few short WOT runs are in order to make sure the motor was
mounted at the right height and the correct prop was installed.

When you reference 2000 and 3000 rpms, you are talking about the max,
right? You should vary your speed during the break in process.


I didn't know for sure I had the wrong prop on my new engine until
about 10 hours because I wasn't willing to firewall it.
That is why I still have a virtually new 14 7/8 x 15 SS Michigan Match
hubbed for a merc
Anyone want to make me an offer ;-)

I agree you should avoid WOT until it has ruin a while and everything
is seated well. The reality is, if it seems OK it probably is but I
wouldn't do that speed test on purpose for several hours.
.
I am at 2550 or so on the clock and I bet I don't have 60 minutes of
WOT in all of that time. I like 4000-4500 if I am going somewhere. It
just sounds better to me and only takes a few MPH off of my speed, at
a significant fuel saving..




Yamaha publishes performance bulletins for Hydra-Sports. The boat in
question will touch 40 mph at WOT with a 15-1/4 x 15 aluminum prop at
5850 rpm. I have a similar prop (in stainless) on a boat about the same
size and weight, and I can pull 6000 rpms and get a few hairs over 40
mph with the same engine, full fuel, and a few guys and gear aboard.
The Hydra-Sports boat is heavy for its length, just like my Parker. No
lightweight crapola used here. My Parker is a bit heavier, actually.

Therefore, approximately 40 mph will be the WOT full speed with this
boat, motor and prop. The Yamaha performance bulletins are accurate.

I'm sure the Hydra-Sports boat handles well. The manufacturer has been
making the model for some years.

I would not run the boat at WOT outside of the stipulations of the
break-in procedures.