C-302 Performance

[Rocky Lou]

I'm curious to learn what others are seeing for performance running with the standard config. Yamaha 300s, 15.25 x 19 props and 89 octane gas.

I'm not getting close to numbers published here: http://www.cutwaterboats.com/Userfiles/ ... 30_OWA.pdf with similar water and load conditions.

Specifically, I can’t get: Optimal Cruising: 3500rpm; 24.9mph; 18.6gph; 1.34mpg. I got: 3500rpm; 20.1mph; 20.1gph and 4100rpm; 27mph and 26gph...so about 4100 seems optimal to me.

I typically get best performance with the engines (and tabs) trimmed all the way down, however, no matter the trim, the speed changes more frequently than other boats I’ve driven that stayed fairly constant, with +/-3-4 mph.

 

[Kevin Lamont]

I'm curious to learn what others are seeing for performance running with the standard config. Yamaha 300s, 15.25 x 19 props and 89 octane gas.

I'm not getting close to numbers published here: http://www.cutwaterboats.com/Userfiles/ ... 30_OWA.pdf with similar water and load conditions.

Specifically, I can’t get: Optimal Cruising: 3500rpm; 24.9mph; 18.6gph; 1.34mpg. I got: 3500rpm; 20.1mph; 20.1gph and 4100rpm; 27mph and 26gph...so about 4100 seems optimal to me.

I typically get best performance with the engines (and tabs) trimmed all the way down, however, no matter the trim, the speed changes more frequently than other boats I’ve driven that stayed fairly constant, with +/-3-4 mph.

Hey Rocky,

I noticed at the end of your post you said you get the best performance with the engines and trim tabs all the way down, typically when I am out testing the C-302 I will start to trim the engines UP at about 4500-4800rpms till they are about half to little more then half way up also I only use the trim tabs to level out the boat if it is leaning to one side or the other. With the engines all the way down the props have a lot of drag but when raised closer to the surface there is less drag and allows the engines to achieve higher RPM's. I would ask to have you run the boat with the instructions above and report back what you found. You can reach me direct at kevinlamont@rangertugs.com and would be happy to discuss this more.

Thank you,
Kevin Lamont

 

[Captain Blok]

Rocky,
It has been my experience that fuel efficiency is not as good, and does not change much until after you hit about 25 kts unless you are really pushing it closer to WOT. I don't think I have ever gotten much over 1 mpg at causing speeds. It does seem to be a little more efficient with the motor tilted up at higher rpms. I have a picture i took last summer 2019 of the instruments when heading across the bottom of San Juan Island on the way to Victoria BC with flat water, full tanks, 4 adults and loaded with gear including a kaboat and 2 SUPs on the roof. At 27kts (about 31 mph) we were burning about 33.4 gph which was about.82 Kpg or .94 mpg. Not sure but we may of had a little current against us.
The numbers I use for calculating my fuel consumption for a trip is 31 kts at 32gph with give us a range of about 260 km and still keeping a 10% reserve.
She is a thirsty boat but a lot of fun!
I could send some pictures of my instruments at different speeds but I can figure out how to upload pictures here.

Captain Blok

 

[Rocky Lou]

Hey Capt. Blok,
Thanks for the comeback. Yes, the Tugnuts website is one of the more primtive out there, particularly for a boating/fishing site where we are all 'gaga' over boat and fish pics. In any case, I know you can use IMG if you have a small sized picture from the web with an http address (hover over for syntax) and g21mg requires you to create a gallery post, after requesting via your control panel, and access pictures posted in gallery. Now, back to boating...

I was on the boat recently and ran some trials. Overall, I get the same results where trimming the engine up degrades performance. The only exception was when I ran WOT and got a slight improvement by trimming up.

To start: the engines were trimmed down, the trim tabs untouched after start up and I confirmed by sight both tabs were all the way up.
- Smooth acceleration to 4600 RPM, 35 MPH, 34.9 GPH:
- Move to 50% Engine Trim: 4600 RPM; 26 MPH, 36.8 GPH
- Backed the Engine Trim to 0: 4900 RPM, 34 MPH, 43 GPH

Second trial moved to 61% Engine Trim:
Again, it slowed way down: 4300 RPM, 16 mph, 28 GPH

Back to Engine Trim down:
Performance improves: 3700 RPM, 19 mph, 23 GPH

From what I’m seeing, Optimal Performance comes from Engine Trim down and
4100 RPM, 27 MPH, 26 GPH

Finally, with WOT, I got:
5600 RPM, 42 MPH, 53 GPH

It's a great boat choice for me...my wife wanted nothing to do with a Grady White 330 express with a cramped forward cuddy. However, I agree that the Yamaha Outboard report is misleading and I called Yamaha to let them know my view on it. They said they would report back to their team.

One other interesting comment someone made on another thread is that CW added two feet to the C302 to improve performance. I have no expertise in that area and it's academic to me in any case since I doubt they are selling an upgrade kit :lol: :lol:

~Paul

 

[Captain Blok]

Nice Paul thanks for the info.
Yeah we were looking at the Gradys too. I always wanted one but definitely too cramped for the Admiral. Plus we like to take friends with us. I love the boat and more importantly she really loves it. Making plans right now to go up to Bella Bella Area in September and stop to do some fishing at Haiki pass where they catch the 60# Chinooks ( they call them Springs up there in BC.) and nice size Butts.
We have a couple that are going up with us and we are looking for someone to make the trip back with us. We have a house in Powell river BC and will take off from there.
Where do you like to go with yours? Do you keep her on a trailer. We're in San Diego during the winter and would love to get out tuna or Yellow tail fishing sometime when it picks up.
Let us know if your in the area.
Captainblok@ganil.com
5417536395

 

[Captain Blok]

 

[Rocky Lou]

Sorry, I don't think I had the chance to reply to earlier. I just moved the boat from Brisbane Marina to Pillar Point, Half Moon Bay. Salmon seasoned opened on the 1st May and I plan to move the boat back and forth depending on the seasons. On the way down south, I fished a bit and caught one nice King. It was not a hot bite and fishing alone is never easy, not to mention they were mostly biting bait and mine was ruined due to a freezer issue.

I gave up trailering some years back. We do plan to do some cruising, but, the range will likely be limited to somewhere in southern California. Fishing BFT in San Diego would be awesome. I only tried there once on a long range party boat and didn't care for that type of fishing, plus it was fairly slow and didn't get a Blue Fin...I think they owe me 😀 I'd love to fish there on a private boat where you are not fighting traffic on the rail.

Regarding performance, the boat ran nicely on the 50 miles trek under the Golden Gate and I mostly ran about 25 knots, getting 0.9MPG ~26 GPH. I'm still baffled that I consistently get best performance with engines trimmed down and trim tabs down also. Do you see the same or do you get improvement trimming up the engines as one would normally expect?

 

[Captain Blok]

I don't trim down the tabs at all except to balance the boat. Motors always all the way down I have tried to trip up the motors and it shoots the rpms up but I don't see any increase in efficiency. After about reaching 25 knots to 35 the efficiency seem to stay the same and not change much. If the conditions are good I figure you might as well go faster and get there sooner.

We're up north now and hope to get the boat in the water soon. Except that fishing is shut down until July. The pawning is supposed to be good though. I am in the process right now of wiring Hot water heater to the inverter so we can heat water while under way.
Still no manual but they say it will be out anyway ( for the last few months)

Have you been watching the webinars? I have gotten a lot out of them.

Catch one for me
B

 

[Rocky Lou]

Well, that sounds pretty consistent, I rarely use the Trim Tabs at all, except in the rare case to balance (correct list) and the engine (tilt/trim) is always down (0%). I agree that the 25-35 knots is about the same, running at 0.9 GPH. The only difference may be that if I do trim up the engines, the speed will decrease, unlike any other boat I've driven.

Yes, I'm watching webinars and like them. I'd like to watch some while on the boat so I can try things in real time. Sometimes you have to translate what they are presenting to our C302, like on the Garmin 101. My auto-guidance does not generate a message to auto-pilot...I have to go into the menu and request that separately. I used it coming down to Half Moon Bay and it was OK. The maps didn't seem to realize that you don't want to get close to the Cliff House as that area is famous for sinking boats due to San Francisco Bar.

Sorry about the fishing restriction, but, I do love prawns. Good luck with the H20 heater project. Most of my interests are in tweaking the fishing capabilities. I've installed the down riggers, some additional rod holders, mountings for gaffs and considering how to best put a cooler on the swim platform. I'll probably just put my rolling Igloo bungeed in. I need a better place for fishing nets than rocket launchers...lots to do.

Cheers,
Paul