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Dialing in the twin 2007 BF225’s

B

beantown

New member
I bought a 1993 Grady White 252 Sailfish near end of boating season last year.
On its maiden voyage, it had tired twin 200 Yamaha 2 strokes, that were so tired
I ripped the block almost in half when a rod in the port motor gave up the ghost.
While limping back on 1 motor, it also died, but with less violence.
After about an hour stranded I found the second motor simply ran out of gas.
Turned the valve to use the main fuel tank (boat was new to me) and we continued the limp back.

Determined to get some boating in late in the season I found two Coast Guard take off 2007 Honda BF225’s with a far better price than new. :cool:

I repowered myself and got back on the water.
Motors stuffed the stern way down with the added weight.
The boat drove like crap with the drives way too low and bow to the sky.
Was still fun, but got researching to try to get her as best dialed in that I could.

Got a a pair of jacks to raise the motors. Added about 500lbs of sand ballast up front. Did some homework for prop selection. Each change made her improve.

Still boated while researching and tweaking as the season came to an end.

With the heavy work completed, just had to do the routine stuff before this season.
Took her out yesterday and what a difference.

The outboard height seems just about perfect now and made a huge difference.
Went from cheap aluminum baseline props to stainless best guess size and pitch.
The extra ballast up front tamed the bow almost completely.

I’m by no means a qualified motor guy, but google helps.
Check out the video and see if there is anything that you think could be improved.
She felt great to me and we were able to get her to 49.x mph and an ego busting wall refused to allow 50mph. Determined to get to 50 we finally found the perfect trim and made us cheer like 10 year olds.

So freaking fun. Check out the video:
[FONT=&quot]252 Sailfish Grady White with twin Honda BF225 - QuickSilver Thunderbolt 15.3” x 19p stainless
[/FONT]https://youtu.be/-Zt9DIjlAvA
 
OUTSTANDING! Those old girls were humming. It looks like everything is mounted correctly and operating well - anti-cavitation plates appear to be correct -riding right on the surface at WOT. I could not see what rpm's you were turning at WOT. It should be in the 5800 to 6000 range.
 
Yes, WOT is in the 5800 to 6000 range.
Obtainable, but not with ease.
I had some 4 blade alum. props on for a few trips. 0-30mph(WOT) in like 3 seconds. haha
I'll see how she runs with varied loads/occupants.

Probably slightly over-propped. I'll know better as the season progresses.
 
I agree with Chawk, that they look and sound pretty good.

I did notice that the starboard engine rpms were at 6200 and the starboard was at 5600. Looking at the engines, it looked like they were trimmed pretty close, but the trim gauges differed....indicating that the starboard engine was trimmed lower than the port.

Assuming that the tachs and the trim gauges are correct, trimming up the starboard engine a little might be all it takes. However, if you do not have trim tabs on the boat, that will affect the balance of the boat. Getting the engines in sync will also just sound even better, although, I did not hear any oscillation indicating that they were not in sync.

If you do have trim tabs....then playing with those also could help you get a little more efficiency.

Mike
 
I was wondering if someone was going to notice the rpm difference. Thought my brother zoomed by fast enough. This was actually one of the last runs after about 3 hours of trying to confirm all systems were good. Kinda playing around. The trim indicator on the port motor needs attention.

The boat does have trim tabs. They were all the way closed on this run. They have minimal impact on this boat and are very slow, but this hull runs really nice and list is minimal if any. (My last boat trim buttons were worn paper thin)I will be swapping them for sure. The stern definitely wants the 2 strokes back and I’m hoping tabs that have more travel will help. I think these are on their last leg. If not, then they are going anyway.

Everything is almost there, but the stern weight vs. bow. Coming off plane can show the light bow and heavy stern still need attention. Even if it stays like it is, I will be happy. Last year I was convinced the Honda’s would never work. The thing looked like a message in a bottle trying to get going. Haha. Now she’s sweet and nimble.
 
I would suggest that you get the biggest trim tab plates you can. Personally, I'm partial to the Lenco electrics. Mounted them in 2008 and not a single problem with them to date. I have the two switch setup and one of those switches is always exposed to the weather. Still no problem.

Also, you should avoid fast deceleration - that tends to push a lot of water up your exhaust tubes - even the revised ones - which can blow you HO2 sensor. Keep your rpm's up until the bow settles down on the water.
 
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