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Roy M · 07-08-2008, 07:22

My 3GM30 F Yanmar moves the boat at 8+ knots at about 3600 RPM, throwing an 18 X 12 Martec Mark III folding 2-blade prop. The engine is mounted off-center in the portside locker of the centerboard trunk area, and uses a 17' long, 1" stainless steel shaft. It replaces an Volvo MD2b which I installed originally. It burns just over half a gallon of diesel per hour, and sounds like a sewing machine - virtually no vibration.

Luis Sa Figueir · 07-08-2008, 10:26

Roy
Thank you for your information. 8+ knots is very good although I was under the impression that cruising RPM was about 2800/3000. What is the maximum RPM of that engine ?
Luis

Jmolan · 07-08-2008, 23:27

Like Rossad I installed a 27 H.P. Yanmar in my 37' Searunner in the 80's. I put it at the bottom of the stairs right behind the centerboard trunk. The box that covered was the same height as the first step on the stairway. I used a folding two blade and had great results with the whole thing. Installed an Aluminum tank Fwd. of the engine in the space next to the board, and above the engine so I was able to fill from the cockpit floor and also use a dip stick to check the fuel level. Having the tank above the engine made it a snap to bleed injectors or change fuell filters.
I do not have any photos of the old boat. Nothing was digital back then of course.

rossad · 07-08-2008, 23:41

My 30HP Yanmar has just been installed so I am about to get the prop and make ready for the coming summer. I am hoping to do 6 knots at 2200 RPM . 8 - 9 knots at Full RPM 3600. with a clean bottom. I did have a Daihatsu 30 but a different configuration that was not good at all. That gave me 7 knots. I reckon with a 37 ft searunner the 30 is just right. The 43 footer has got a 40 HP which is ideal for that boat. But everything end the end comes down to the prop. This size, pitch and position.

manawa · 08-08-2008, 01:58

Hi Rossad
which series 30hp did you go for and what are your thoughts around the gori props,
M.

Roy M · 08-08-2008, 08:26

I have not run my engine at max RPM yet, other than a brief dash up to about 3700 for a couple seconds. The max is somewhere around 4000, I believe, for my combination of prop and hull. I just installed a Gori on a 43 foot catamaran, and if I find myself with an extra $4000 I might just pop for a new prop - it really is nice to have that level of control in reverse.

rossad · 09-08-2008, 12:46

Gori Props are as good as you can get. Only trouble is they are exspensive. 2 bladed are cheaper. 3 bladed are better. Keeping the cost down with a prop is not easy unless you can get a deal in the marine world. Once you order one you hope they have got it right size and pitch because if my engine cannot rev at pretty much 3600 then problems may occur. To get the prop repitched cost more. so you really have to do some homework and pray you got it right first time. It can mean the difference with labouring your engine and not getting maximum speed. I believe you should run my 30 around 2200. That way it will last forever..
Rest of my life. I also believe the Yanmar is the best. It took me 8 months to choose my 30 yanmar.

rossad · 11-08-2008, 15:39

Manawa: The engine Model is 3YM30 http://www.yanmarmarine.co.nz/_attac...0_TechData.pdf
I soon realised that reconditioning an older engine and looking at replacing the bits and pieces like pumps alternators etc I was better to buy a new one. I have included a pic for you to see.
Most importantly it should hit out at 3600 revs. That is part of the testing for getting one's warrenty with a new engine. Also to remember that with a new engine one needs to replace the oil and water soon after ..... I have heard new engines not having these changes and have major problems, peopling thinking its new.... nothing can go wrong.

Luis Sa Figueir · 12-08-2008, 06:22

Hello everybody.

Here I am again. As I mentioned before I went to see the CC44 this last Saturday. It was a said visit because as expected the “small” repairs mentioned by the seller is NOT small at all. It is enormous. Around all the hatches and the hatches themselves there is rot. As suggested by Roy I took some pictures,
Those are just a few examples. In side the boat I did not fid any rots. The hulls seems to be ok. I made him an offer subject (if accepted) to take the boat out of the water for a final examination of the 3 hulls Let us see what is going to happen.
I would like to take this opportunity to make another question. The rudder/helm system of the boat it not like the other photos of the sea runner that I saw here I the internet. The last picture is what I saw.
Is this ok ? Can somebody tell me how it is the system utilized by the sea runners ?
Thank you.
Luis

Roy M · 12-08-2008, 08:37

Luis, Although it is difficult to understand where the damage is located, relative to its position on the structure of the boat, it appears small, not major. Did you try tapping the perimeter of the damage with a solid object, as described earlier? Where, precisely, is the dry rot damage?

Though unusual, having the quadrant external to the hull, the rudder control hardware looks serviceable. The narrow tab, facing aft, appears to support a possible trim tab. All of this can be changed, if you prefer. Write John Marples to obtain plans for the Searunner rudder hardware layout.

The addition of the quadrant, normally inboard, at the terminal end of the "wiggler", was a new improvement which I will be using when I install my autopilot. My steering was originally designed for the Morse/Teleflex single control cable. I converted a couple years ago to an Edson, dual cable control. I was unhappy with how the cables terminated at the rudder hardware, so John Marples set me up to make things much better.

rossad · 12-08-2008, 14:28

Luis
This boat has got rot. You need to see how exstensive it is. So it must come out of the water. It would be a good idea to have somebody else go over the boat with you that knows about tri's and where to look. Relaxed second looker is comforting.
thats my view.

**Steve Rust** · 12-08-2008, 15:03

This page details the original design of the "wiggler" using the single cable steering. I have hydraulic steering so mine is similar. It is attached to the forward end of the rudder and extends inside the transom. It looks like the rudder quadrant has just been designed inside out on that boat. For dual cable control this would be modified by adding a quadrant. The quick release mechanism is for windvane self-steering and could be omitted if you did not have plans for a windvane. As Roy states, contact John Marples for plans on the newer version. I would also check with the owner and see if the building plans come with the boat. I am not sure if the Searunner Construction manual came with the Constant Camber designs, but ask the owner if he has this also. I have seen copies on E Bay from time to time. It is well worth having.

Some boats have 4 chainplates attached to the main bulkheads (2 forward 2 aft) for lifting the boat by crane using a wire bridle. Check where these pierce the deck and also the area around where they bolted to the bulkhead. They have never cause a problem on my boat but I have heard of one instance where they did.

manawa · 12-08-2008, 15:21

Hi rossad,
thanks for the photo. The Ym series is the one I'm looking at. Very sweet motors, got a price of around A$9000 for the motor. Your placement makes sense too as far as access for instal and maintenance.

As far as the rot goes, you either walk away, or get it out of the water and go right over it with someone else you trust will be honest. The rot in the photos is all fixable but it all takes time. With the ply boats there is process you have to go thru to protect the ply and there are really no short cuts. having just spent 2 years doing what I thought was going to be a basic repaint and a repair here and there and my boat didn't really have any rot issues. The CC44 is a hell of a big boat so you have to really want to spend a lot of time surrounded by dust, noise and sticky stuff and weigh that up against the asking price.

If you love all that then you'll be in heaven.

M.

Roy M · 12-08-2008, 15:32

Guys, I'm afraid I have to disagree regarding the rot. Unless the boat has been sitting on the hard for some time, holding freshwater in the bilge, the likelihood of there being rot below the floorboards is low. The chance for rot would be where there is a crack or leak, above the waterline, where freshwater can accumulate over time without getting a chance to dry out very much. With the boat in the water you can still use the tapping technique to "sound" out the potential rot areas, then determine the extent of damage before conducting more destructive testing, say, with a drill bit. BUT MOST OF ALL, get us some photos of the damaged areas showing where they are relative to bigger, identifiable sections of the boat. Whether the damage is structural or cosmetic is impossible to determine from the pictures you have given us already.