07 Honda 90 with fuel injection

[mcolp]

Hello out there!

Our new (06) CD 22 is getting rigged with the new 07 Honda 90.
I haven't seen any posts on anybody that has one on their CD22.
I've read all of the specs and info I can find. Even the dealer will
have to experiment on which prop to use. Aside from being a
re-design the gear ratio is now a 2.33:1 vs. 2.30:1 on the
previous BF90's. I'm assuming that the new 90 will theoretically
be able to swing a higher pitch prop due to the slightly lower
gearing. (maybe a 17?)
Any thoughts out there?

Mike

[Sea Wolf]

Mike-

The change in gear ratio from 2.30 to 2.33 is only 1.3%, very small indeed!

The change from a 15 to a 17 inch pitch prop is 12%, or about ten times as great as the gear ratio change!

The gear ratio change won't itself make any real difference.

The only possibility for change in this area would be if the new Honda 90 were to put out 5-10% more (or less) horsepower than the older one.

Several have suggested that the new Honda 90 is, indeed, stronger than the older one.

I personally doubt that the new engine will allow a 2 inch increase in pitch across the board to most owners over the old one.

If it is measurably more powerful, a change of 1 inch in pitch, or to a cupped prop, or to a prop with more blades (or some similar option), would be more likely in order.

Let us know how it works out!

Incidentally, here's a LINK to an interesting article on the new motor.

Joe.

[Wefings]

The Honda is definatley more powerful and responsive than the old carb 90 . I was with the Honda techs at Miami with a C Dory 22 rigged with the new 90 . The prop that they chosen was the Solas/Honda 15 p. It workied well with light load or heavy load . The new motor is 6300 RPM redline , which sort of negates the gear ratio change . We saw 36 MPH trimmed all the way with 2 aboard [light] and Boatttest.com got 32+ with a load . The boat was in the correct range for the RPMs in all conditions . The boattest.com video should appear on their site soon .
The motor has a very snappy midrange , and is a good match for the CD 22 .

Marc

[Byrdman]

Thanks for your input Marc for the particular use on the CD22.

It does look like initial reports are very favorable on this motor. While in Miami at the boat show, just kinda cross the docks from where the CD22 was in a slip, near a food stand, while waiting in line for stuff...I heard two guys talking about how strong this particular motor would be in the market once out in dealerships and on some local boats... Interesting point, is of course that they were each factory folks....from Suziki and Yamaha having a discussion. Ya gotta love good ol competitive markets.

I do not think there are any bad new 4 strokes out there...but, for sure will be fun to watch this motor get onto the transoms and do its work.

I loved my pair of 90 carb'd Hondas on my TC24.... Never a minutes problem, always reliable, always faithful.

Byrdman

[jlastofka]

Hi,

I finally got about six hours on my new 22 cruiser with the VTEC 90 and got on some sort-of-smooth water in our outer harbor area. I can leave the trim tabs up and the engine trimmed all the way down and just launch up to plane like that. The bow doesn't head for the moon, and friends who were on shore said the boat rides nice and flat and they commented on the bow not rising too much, also. (It's nothing like a Malibu ski boat, for instance, but much better than a lot of deep V fishing boats).

I ran wide open for a bit and just topped 27 knots on the GPS (31 MPH). About 6000 RPM I think I remember.

I'm not usually a wide open throttle kind of guy, but I wanted to check it out after it had a little running time on it. I'm pretty impressed.

I haven't tested trim tab and engine trim carefully, but leaving them alone seems to work quite well. I'm running with the starboard tab down just a touch to level out my solo driver's weight.

Jeff Lastofka

[dogon dory]

Sorry, Folks - Post Deleted By Author

[tpbrady]

Jeff,

I started with a 3 blade 15P Honda Solas which got up 6300 RPM but the motor was too low. Raised the motor one hole (the last one) and put on a 4 blade Solas 15P. WOT was pushing past 6300 when I ran out of water. Cruised 95 miles on the Solas 4 blade but got pretty poor fuel economy on a very heavy boat. At WOT 6200 rpm got 31.8 mph. Switched to 17P 3 blade Honda Solas, WOT 5400 and 30.5 mph on heavy boat. Fuel economy on the return trip of 170 miles was 3.8 mpg. Started out with heavy boat and lightened up as fuel, water, beer, and food got consumed. At the end of the trip, WOT was 5600 with speed of 31.5 mph into an outgoing tide of about 1 mph.

Best cruise was at 4300 to 4500 rpm 20-22 mph. The motor just sounded right at that rpm. It does squat at the stern a little more and I am still suspicious that the motor is a hole low with no more holes to go and no more transom left to raise it. At most speeds the cavitation plate is about 3/4 to 1 inch below the surface of the water. When trimming up for best speed/rpm you can tell when it comes out the water.

Overall, the 17p propeller did a better job. It didn't have the raw acceleration of the 15p, but it was more than adequate and the fuel economy improvement was immediately noticeable after I put it on.

I'm considering a Permatrim as a way to improve the performance in the 14-18 mph range, as I have to use trim tabs to get the most efficient combination of motor trim and boat trim to get best economy, which is less than the economy I see at 20-22 mph or even see at WOT. Not that I run there very often, but the boat wanders all over the place at 30+mph. There is just not enough hull in the water to track straight. I understand the permatrim helps tame that characteristic.

Tom

[thataway]

My experience with the older Evinrude on a 22 was about the same as Tom's--we could get a little over 30, with a light boat. However, at that speed the boat was "dancing" around a bit--not a control problem, but not positive steering I have had with most other boats.

I wonder if the new engine has more low end torque--and that would allow a decent hole shot with the larger pitch prop. Although "over propping" can give slightly better fuel economy, it may be harder on the engine; tend to lug it at lower speeds.

I suspect that the Permatrim will decrease the planing speed, but in my experience on other boats, fins tend to slighly decrease the fuel economy. As long as the boat is trimmed properly, (and the 22 we owned did fine without any fins or trim tabs--but it would have been nice to get the bow down in chop) you will get better economy with less metal or plastic dragging in the water. Even though the Permatrim sits on top of the water when at planing speed in the Tom Cat, it seems to slighly increase the fuel consumption. It does put up quite a stern wave at specific low speeds--enough to avoid these speeds--in the 8 to 10 knot range.

[tpbrady]

Bob,

The WOT throttle range on the new Honda is 5300-6300 RPM. At 5600 I am at the low end but still in the recommended operating range. I may try a 4 blade Solas 17 pitch. On my old ETEC, there was no difference in WOT rpm between the 3 blade stock prop and 4 blade Solas both of 15P. The Solas 4 blade was .75 inch smaller in diameter so that's probably why it didn't affect it. The four blade gave better acceleration and fuel economy was about the same.

The main differrence on the new Honda I have noticed is the low end. If you hit it hard out of the hole, the motor gives a noticeable boost in acceleration (kind of like nitrous on a car) that you can feel. On my typically loaded boat with the 15P 3 blade, and the motor a hole too deep, it would only perform decently with the engine in full down trim, but it would come up on plane in what seemed like a couple of boat lengths.

The jury is still out on props, but I'm leaning toward 17P as the right pitch in 13.75 diameter Solas prop. I gained almost 1 mpg after the switch. That was a nearly 30% improvement that translates to a lot greater range.

Tom

[mcolp]

Tom,
I finally got the hull wet for the first time on my CD22 with new
Honda 90 VTech. I purchased the boat from Stateamind Water
Sports in St. Louis. I know it sounds insane but this is the first
time I've had to get our new boat out. The boat came with
a Honda Solas 15 pitch 3-blade. Due to the altitude being around
5000 ft here I'm immediately down to 72hp. I decided to order a
Solas 4-blade with a 13 pitch.
Note: Assumption was 4% power loss per 1000 ft = 18hp power loss.
The 90 is mounted in the lowest hole and the anticavitation plate
appears to be even with the bottom of the hull.
The boat was lightly loaded (The Wife and I) and after I put
approx. 2 hours on it trying to follow Honda's Break-in recommendations
I decided to try WOT to 5800 rpm which it got to fairly quick.
The GPS showed 25mph@5700rpm. The boat appeared to be
very stable but here's the rub. The boat seems to squat in the stern
for sure. In order to keep the bow from pointing at the sky I had to
trim the engine all of the way in/down and the Lenco 12x9 trim tabs
were all the way down. I guess I'm not used to the attitude of a
C-Dory in the water. My last boat was a Sea Ray 210 cuddy w/Bennett
trim tabs and when getting on plane I put the trim tabs down the boat would level out immediately I would run the trim tabs all the way up and trim the lower unit up and presto, the boat was level.
After much experimenting with engine trim and trim tabs the bottom
line is that my CD22 seems to run fastest with the engine trimmed
all the way in and the trim tabs all the way down. Is this typical?

Thanks,
Mike

[tpbrady]

Sea Wolf, if you are there you might want to chime in, but here goes my shot at it.

Mike,

I think your motor is too low. As the water leaves the stern of a boat, it tends to rise up. Because of that mounting a motor with the cavitation plate even with the bottom generally results in a motor that is too low. When my motor was first mounted it was like that and I would run fastest with the motor trimmed all the way down unless I was at WOT in which case I kept trimming it up trying to make the prop cavitate. In my case I couldn't make that happen at all in the testing I did (I was limited by rough water, but got up to WOT at 6300 with a 15P three blade prop. At nearly WOT throttle I handed the helm over to a friend and and looked over the stern. The cavitation plate was at least 2 and probably 3 inches under water at 22 mph (4900 rpm). If you look at the black plastic cover over the bolt where you adjust steering trim, that was underwater.

In addition I had limited trim control with the motor. Generally you raise the bow by trimming the engine up allowing the stern to sink. When I did that the boat would slow down noticeably with little bow rise but as I increased it the bow came way up and the boat slowed way down. I could run unless it was at full motor down trim. I suspect the reason behind that is I was trying to lever the cavitation plate out of the water and the resistance slowed the boat down significantly and eventually drove the bow up.

At that point I went back to have the motor raised until the upper bolt is in the lowest hole. Now when you place a carpenter's level on the stern and look at it in relation to the cavitation plate, the plate is a little less than an inch above the level. Now it acts more normally in regard to raising the bow. In fact as you trim the motor up from the full down position at moderate to high throttle settings the rpm increases which is what you would expect to happen. The black plastic cover over the steering trim bolt is now visible at the the water line. The cavitation plate is still underwater, but that was at a moderate power setting of 4300 rpm.

Now in a speed run to determine WOT throttle, I can finally make the prop cavitate, but only when I go past the level trim indicator on the trim meter. My method to determine WOT is to go to full throttle, and then trim the engine up (no trim tabs deployed) to maximum rpm that is the engine can sustain without the prop cavitating. This is obviously determined by boat loading and water conditions, so I did it with a heavy boat on as flat a water I could find. I got 5400 in the first test and with a lighter boat at the end of the trip, I got a hair more than 5600 rpm.

I have never seen the proper method discussed to determine WOT RPM on the site, so I will defer to Joe on Sea Wolf or anyone else to correct my test procedure.

My judgement is the motor is too low in the water.

Tom