Anybody running a single G2 Etec?

[grady_22]

I have a new 200HO G2 on my 244 Grady Explorer and still trying to dial in my setup with motor height and propeller selection. I have had it out a total of 4 times with 28 hours on it thus far. The mounting dealer started high on mounting position and worked their way down to the present mounting position, which is one hole from the lowest mounting position. I had received a 15 x 16 RX4 prop with the motor from the boat show sales promotion and that is what I have been running.

The first three runs with the motor were on relatively calm water striper fishing back in the spring. Motor ran great, pulled 5450 for WOT RPM, no noticeable ventilation, could trim the motor substantially before inducing ventilation into the prop. Thought I was good with this setup.

This past week I took the boat offshore for the first time. Seas were smooth (2ft @9s), however while cruising, occasionally I was noticing the RPMs would rise from 4200 to 4400 or so while the speed simultaneously dropped 2 - 3 knots, indicating some ventilation was occurring. After paying attention closely, I realized this would happen after hitting rougher patches of water which would make sense.

I have a 15 pitch Rebel prop that I am switching to in an attempt to see if the RX4 is to blame, before I start to look at motor height. It seems strange that this would be a motor height issue though, as I am coming from a Gen 1 ETEC and had played extensively with motor height on that setup and found that there was a sharp cutoff between the right height and too high. With the engines current position, all clues indicate that I am at the correct height.

Is there anyone else running an ETEC G2 in a single application currently? I would be curious to hear your experience with motor height and prop selection.

Thanks

 

[artodea]

Your ventilation with that prop is not a motor height issue. I believe it is an unfortunate characteristic of it's aggressive profile and going lower won't eliminate it. I get the same thing with my RX4 (16 pitch) when I'm running in rough seas into the wind - it's almost that the resistance/load just overwhelms the prop. If I fall off the wind, the revs drop, speed increases, and mpgs go back up. Also try increasing your speed to see if the prop can get a better bite. It is weird. A prop shop suggested that I add a little cup to the prop at the expense of some top end speed - but I haven't done that yet. Try your three-blade Rebel and report - 5450 is right at the low end of the proper WOT speed and a 15 could get you up into the upper end of the range (which you want).

As for mounting height, with someone else driving the boat, look over the transom at the position of the anti-ventilation plate relative to the surface of the water when running on a plane and properly trimmed. It should be fully exposed, right at the water level. If it is submerged, you are too low. The G2 wants to run high for best efficiency.

This is where mine was installed (one hole up) which was too low. It's now all the way up, and I'd go more if I could:

 

[grady_22]

Thanks for the thorough reply. I am at the proper motor height as the next bolt hole up the prop was ventilating very badly with anything beyond being trimmed down all the way, and ventilating badly in turns as well. I was hoping someone posting back saying it was a prop issue, because what was strange to me was that if I tucked the motor all the way down, the issue persisted, if I had the motor mounted too high, tucking the motor should have helped. I am hoping to get offshore again next week, so hopefully will be able to report back.

 

[grady_22]

Well, ran my 15.75 x 15 Rebel yesterday. Ran 160 nm and got 2.4 nm/g combined for the trip, including 50 miles of some sloppy seas. The issue did not show up with the Rebel, so I am glad it is just related to the RX4. The G2 turns the Rebel much better than my G1 200HO did. Glad I had not sold the Rebel yet.

 

[family affair]

I know the 200 HO is based off the 300g2, so it likely makes a lot of torque. A 200 4 stroke would struggle to move that boat. How does the 200 HO do?

 

[grady_22]

I know the 200 HO is based off the 300g2, so it likely makes a lot of torque. A 200 4 stroke would struggle to move that boat. How does the 200 HO do?

My old g1 200HO would turn a 15 pitch Rebel to 5450 rpm at around 32-33 knots. In the slop it used to struggle turning that prop to stay on plane below like 21-22 knots , so I had switched to a Cyclone 15 pitch 4 blade and had slightly better hole shot and it would turn 5650 with the same load and easily maintain a 16-17 knot planing speed.. With the G2 200HO the low end torque and midrange blows the G1 out of the water so to speak. I easily was turning that same Rebel prop at 14-15 knots planing speed in the slop on Tuesday. With a full offshore load I was able to hit 5450, so I am assuming with a more normal load, I should see 5650-5700 rpms.

What is interesting about the G2's is for the most part the lower horsepower versions of the big block are just detuned, you still maintain the low RPM torque and midrange up to the point where they start to pull fuel and timing out of the ECM. On my motor I would say that point is around 4000 rpm. Power feels decent up to around the 5000 rpm, and then it just feels kind of flat beyond that. Speed still increases, but I never run up in those RPM ranges, so to me spending extra money on a 250 or 300 doesn't matter.

 

[family affair]

Impressive. There is a lot more to engine performance than the hp rating.
What is 4k rpm speed? Please let us know when you run wot and what your numbers look like. Curious because the g2's dont seem to lose much efficiency wot compared to 4-strokes. I'd love to have an efficient fast cruise (35-40) for days that allow it without sucking down a ton of fuel.