32+2 Speed

[Farmer38]

Hi there,

So glad this community is here - thank you. I have been the proud owner of a 2000 32+2 since November, and have put many enjoyable hours in.

I am noting that many 32+2 owners are achieving speeds upwards of 16-17 knots. I'm wondering what I'm missing?

I'm topping out about 12 - 13 knots, with current I may get to 14, for a brief minute or two.. I've got a solid Yanmar 350HP 6LYA-STE, recently serviced and running well. Had an engine survey done at purchase and all came out "normal."

I am seeing a bit more blackish smoke than I would like at 2400 RPM, but it isn't too bad. Steam starts to appears at 2400 and up. Engine sounds good, starts up and behaves really well. She likes to run!

So, while mostly I love to trawl with my trawler boating friends, there are times I want to get up and go to catch up with them ( I still have a day job....) and would love to hit "cruise at 14-15 knots at say 2700-2800 RPM.

Thoughts?

[Mark Deeser]

Noticed motor just serviced, did that include injectors and valve set? Is that a recent picture of prop and bottom? Have you seen any change in engine operating temps? Thanks, Mark.

[Farmer38]

Thanks Mark,

This photo is from the haul out in November at the sea trial. We achieved the same top speed then, as now. I have kept up with monthly bottom cleanings.

Excellent question re maintenance. The tech did NOT do any work on the valve set or injectors. . . instead did "the real world 2000 service" had my turbo rebuilt and replaced the zincs and riser that was rusting. I suspect from your questions I may have a repeat 2000 hour service in my future...?

[Sanatee]

Our 96 32+2 with a 315HP Cummins cruises at 16.5-18.3 kts at 2400 rpm (full fuel and 2 aboard). We have a canvas enclosure (think weight!).

We have compared performance with other owners of 32+2's and we're usually faster by 2-4 kts. But many of them have hardtops and some also have hard cockpit covers. So I think weight is the most common culprit. Another possibility is wrong prop or prop pitch. What kind of bridge enclosure do you have?

We keep Sanatee on a lift so the bottom is always clean. But yours looks clean in your pictures.

If you can maintain 2400 rpm under load, I wouldn't suspect an engine or fuel filter issue.

[Farmer38]

Thanks!
I have a canvas enclosure and a bimini over the cockpit. Some extra weight on-board, but not too much.

[Sanatee]

Thanks!
I have a canvas enclosure and a bimini over the cockpit. Some extra weight on-board, but not too much.

The black smoke could be injectors or air cleaner, but if you can maintain 2400 rpm you should get more speed unless prop is not right and/or your trans gearing is different. Puzzled!

[Farmer38]

Hi, Thanks for hanging with me on this!

I am excited at the prospect of gaining top end speed and increased fuel efficiency to speed ratio. Fresh off a bottom cleaning we went out for an evening cruise. At 2900 RPM I can still only make 12 knots. Engine sounds great, can hold easily (so it feels) at any RPM it is brought to.

The sunset was beautiful, and we beat the rain back to slip.

[Sanatee]

Hi, Thanks for hanging with me on this!

I am excited at the prospect of gaining top end speed and increased fuel efficiency to speed ratio. Fresh off a bottom cleaning we went out for an evening cruise. At 2900 RPM I can still only make 12 knots. Engine sounds great, can hold easily (so it feels) at any RPM it is brought to.

Ugh....at 2900 (WOT for the Cummins) I would be doing 22-23kts. Does the boat get up on plane at all? Trim tabs will help but not 8-10 kts worth. Either you have a lead keel (not really!) or it is propped wrong or.....???? I would find a good mechanic and/or prop person and take them for a sea trial.

[Farmer38]

Met My diver at the boat today had him read the prop numbers to me.. 20L20 NI. Looking through the threads I see most 32+2 are running what I believe to larger props than this.. I need some prop expertise.. Is there any way to find out what the boat shipped with from the factory?

Best,

[Sanatee]

Jim

Our boat came with a 22x25 from the factory (I bought 2, one for spare). I did have one computer tuned a little by Black Dog Props. But it sounds like you are seriously under-propped.

[Farmer38]

Thanks - I very much appreciate this info. I must keep in mind the motor differences between our boats I'm sure.. Any ideas why would a past owner consider such a serious under-propping?

[Sanatee]

Guess you need to check with other owners powered by Yanmar. Maybe Yanmars can't sustain optimum rpm with the bigger props. But that's a poor trade if it degrades your speed that much. You might get some help from Yanmar if you describe the boat, hull shape, displacement, etc. Or find a really good prop shop with good software and tools...they may be able to figure it out. We used Black Dog in MD, but there are bound to be some good ones in FL.

[Farmer38]

Hi - An Update. Well not much of one but some new info.

Interestingly, the transmission is not one of the marine transmission ratios listed on the Yanmar engine table.. Looks to me to be 1.882/1

I have a prop shop running all the info and hope to have his recommendation back shortly...

Thanks!

[Farmer38]

Well here is what the prop guy said...

"Sizing shows 20 x 22 four blade, should max out about 19 knots. You obviously can't turn that-20 x 20 won't even get 3300, so optimal size is 20 x 18 or so to get 3300. That won't get you more speed. If you could turn the 20 x 22 you'd get better speed--but you can't, so you won't.

My guess is that the boat is a good bit heavier that it was when new. Or maybe less HP than new, or combo of both. It's a pretty common problem--speed is directly related to HP and weight. And once you start adding weight and reducing HP the results tend to be pretty dramatic.

So unless you can get more HP or less weight (or there's another easy problem--like dirty bottom, or propeller that's in such poor condition that it's not efficient) you're probably stuck with a fast trawler."

Thoughts? I think I'll do some more research.. knots at 2900 with 1/2 fuel and 1/2 water tank and not a lot of extra stuff or people on board just seems pretty below the norm fr this vessel..

[Farmer38]

I've been a bit leery of going to WOT, should I be?