auxillary power for a 1980 CD 28

[warrenescape]

I have recently purchased a 1980 CD 28 - located in SF CA - had a lot of work done by the boat yard - but the Volvo diesel is overheating - I am a bit at the mercy of the boat yard since I do not feel I can return to the slip w/o a better solution. While I am willing to go the overhaul or repower route - I would like a little time to think about it (shop around) and look into options w/o being pressured to have it done now.

I had thought about an o/b to have as a back up (if I do a little cruising) - before the overheating problem. Would appreciate some feedback about hanging a 15 hp o/b off the stern - to buy me some time in my reower decision - or is that just additional unneeded expenditure? What has been the experience folks have had with aux power?

Many thanks for the feedback - Warren

[tartansailor]

Warren,
I have a CD 25 with a 8 hp Honda.
IMHO the 8 hp is way more than is needed to push my boat at close to hull speed in even a most bumpy sea state..
If I were in a similar situation I would certainly go ahead with the outboard option, and defer a decision on the inboard until you can get a definitive diagnosis of your inboard.

Now having said that, if you go the outboard route, be certain to get
a propeller with less than a 7" pitch 5 would be my choice.

Dick

[Dick Kobayashi]

Before spending a penny on an ob. Check or have a good mechanic check all the most common reasons for overheating. Overheating usually means there is not enough water going through the system due to clogs, poorly performing pumps, bad hose connections or similar, all assuming this is a raw water cooled engine. The cooling systems in these boats are pretty simple and straight forward. I recommend starting at the water inlet and proceeding through the water cooling system. Tedious but not expensive.

[warrenescape]

Dick - thanks - I have taken off every line/hose - seems the blockage is in the engine - strong flow into and a mere trickle out - hard to "snake" around the engine to pull off parts to repair/replace - also a lot of rust on the back of the engine - don't know if that is normal - Warren

[Duncan]

I was thinking "muriatic acid", but when I googled it up, it turns out you could also flush with oxalic acid or even just vinegar.

Here's a "How-To" and some comments

From the sounds of the comments there, you might end up pretty happy with the results.

[CruiseAlong]

The outboard option is not inexpensive but certainly less than a rebuild or new diesel. Not knowing if the marina took a look at the diesel and had run a few tests it is hard to advise. Many small things can cause the overheating....making some personal observations may give some indications......some which come to mind is....temperature measurements of inlet/outlet water temperature should tell the tale....Once you know where the problem is then a decision of the outboard would be in order...

1. Observe a real good glup of water coming out the exhaust very couple of seconds......
2. Engine thermosat is opening up when warm. Remove and put in pan of water on stove and observe temperature it opens at.
3. Exhaust riser pipe is partially plugged with carbon....diesels do not like exhuast back pressure...will overheat....
4. Raw water pump impeler is worn or vanes are broken
5. Engine fresh water coolant pump is bad....
6. Plugging or scaling within the raw water to fresh water heat exchanger....most likely location.....
Dana

[sealark]

Warren,

Two months ago - I was in your EXACT same situation - kind of. I purchased a 1979 CD 28 in West Palm Beach, Florida. Unfortunately - I didn't even have a poorly working inboard - I had no inboard. The PO had removed it and it was gone.

The PO had installed a Garelick adjustable outboard mount. I went back and forth for quite some time debating my options. Unfortunately - I needed all new rigging and opted for the brand new rigging in lieu of a new inboard engine.

The PO had installed the bracket off to the port side - I moved it to exact midship - as low as I could possibly get it.

I purchased a 15 year old Yamaha 2 stroke 8hp with a 20 inch shaft from someone at the yard. I paid $300 for the engine. It is a pull start with no alternator.

Now the big thing - performance.

From my own personal experience now - the 8HP is more than capable of pushing a CD 28 in coastal waters (not a lake). I live in Saint Petersburg Florida and I sail in Tampa Bay and the Gulf of Mexico. Measured with a GPS - I have done 6 knots with the motor - and that was not at full throttle.

I will say one thing - I don't go out sailing when it is really rough - so I can't really speak to it's performance in rough seas - but dealing with tidal currents and other boats wakes has been a none issue.

Because I have the mount so low now - even with only the 20 inch shaft - the prop never comes out of the water. With a 25 inch shaft - you would have even more depth.

Steering with the tiller on the outboard when it is very low is impossible. The outboard I have locks in place - so I lock it and use the boats tiller to steer. This set up works pretty well. I made an extension for the forward/reverse - so I can shift from the cockpit. They make extensions for the throttle - but I just hang over the stern to throtte up or down.

I think the outboard setup is a perfectly viable and economical choice if your primary use will either be temporary movement or daysailing. Even if I had to purchase the bracket - the whole thing could still have been done for under $600.

I will say this - I am not convinced the outboard is a permanent solution for me - simply based on looks. While it works - I simply hate the way it looks.

I am looking at the Electric Inboard with a diesel generator as a permanent solution - but until I can afford it - I will continue to use my current set up to get me out every weekend.

Sorry for the long winded response - hope all this gives you some better insight. Feel free to email me if you have any specific questions.

Kevin

[Sea Hunt]

I recently looked at a Cape Dory 27 in the Florida Keys. It had a Yanmar diesel that allegedly worked (we did not start it at owner's request - suspicious ) and a 9.9 hp Mercury O/B hung off the stern. Broker could not explain why the O/B was there and suggested it was for "back up". I concluded either the Yanmar did not run or ran only intermittently and thus the O/B "solution".

I guess I am a purist, but it just did not look like a Cape Dory 27 with that "thing" hanging off the stern. I spent about an hour inspecting her and was always turning around to look at that "thing" hanging off the stern. It's one thing to hang a small 2.5 hp O/B off the stern rail to be used for a tender. It looks like it belongs there. It is something else to hang a huge 8 or 9.9 hp (or 15 hp) O/B off the transom with a large bracket bolted to the transom.

Cape Dory sailboats are true classics. In my opinion they should be maintained as close to original as possible. Safety upgrades are good. Interior cabinetry teak work upgrades are also good. Sticking an O/B off the stern is not good.

I have a small 6 hp O/B Suzuki off the stern of S/V Tadpole (a Ty Weekender). I need it for safety but recently started learning to sail off of/on to my mooring. The O/B was at home. It just felt different - a good different

CD 28s (as well as CD 27s, etc.) were designed by Mr. Alberg for a small diesel auxiliary. I vote to keep it that way. As suggested by others I would first spend the time (not necessarily money) to determine the cause of the overheating. I think Dick K. has it right. Get a reputable diesel mechanic to assess the motor and determine the cause of the overheating. It may well be a simple fix. Having a mechanic look at your motor just to assess it should not cost much.

I agree with taking time to decide about a repower, rebuild, etc. Lord knows, I have taken my time on everything involved with S/V Tadpole. Not sure how far your CD 28 is at present from your slip. Perhaps you can have someone motor with you in their boat and do a "hip tow" or similar if the Volvo overheats too much.

Warren, I am very old fashioned in my ways and my thinking and apologize in advance to all for this long winded response.

[bill2]

I agree that if there's no obstructions on the intake and little coming out that you're looking for restrictions inside the engine or the exhaust manifold/muffler(?) if not the water pump ( impeller would be suspect ) . Muriatic acid or oxalic acid being the typical solvents ( though vinegar also ) may prove to be simple ( inexpensive ) fixes before you go through the expensive solutions .

I have seen other Alberg designs ( Tritons for example ) that the owners had hung ob's on - though not elegant they seemed to be functional ( Chesapeake Bay boats mostly ).

Good Luck


Robert - very suspicious asking you NOT to start the engine on a boat you're buying if told that it works !

[Joe CD MS 300]

Warren, I'm kind of with Dick on this. The thought of an outboard hanging off a CD, yuck. Has the heat exchanger been "boiled" recently? I think that need to be done every few years. I know from my PO's log it was done every three-four years.

You might want to invest in Don Casey's book or another diesel maintenance book. What does the trouble shooting guide in your manual suggest?

Joe

[M. R. Bober]

A couple of thoughts: 1) Is the transom "strong enough" to cope with the load/thrust of an OB, 2) Putting 70-100 pounds at the extreme aft end of your boat will effect trim, and 3) How will you safely carry gasoline?

Mitchell Bober
Sunny Lancaster (where just because something is a bad idea doesn't mean that a sailor won't try it, )VA

[Boyd]

Its generally cheap and easy to fix overheating problems. Your problem could be nothing more than a clogged fitting at the exhaust elbo or a bad impellor. Until you have diagnosed the extent of your engine problems dont give up on the Volvo and put on an OB with all its inherent problems.

The OB will come out of the water and lose bite when your in any kind of seas. It was a marginal means of propulsion on my old Hunter 23 which was designed to be OB powered. Sure it works in fairly calm situations, but when you really need it the prop is just spinning in air or the power head is half submerged.

Boyd
s/v Tern
CD30 MkII
Fort Lauderdale, Fla.

[Michael Abramson]

Warren

I have had all sorts of overheating problems on my Volvo MD-7a and they are usually easily repaired.

Remove the water inlet into the water pump and then open the engine seacock. If you get full flow to the pump, it eliminates the water jacket around the transmission being clogged.

Remove the 4 screws that hold on the cover of the water pump and check the impeller is intact and that no old vanes or debris is stuck in the outlet to the engine. Make sure the cam (lump of metal inside the pump) is intact and attached, it is screwed in place and can come dislodged. If you don't know the age of the old impeller, replace it with a Volvo or Jabsco one and save the old one if intact as a emergency spare. The Volvo one comes with a gasket for the cover, you will need at least one of these.

Next check the thermostat , I have found in a raw water engine, the stat itself can corrode to the point of total failure. There are only about 3 bolts holding the housing in place. Buy the Volvo part, it should come with the main rubber perimeter seal, and 2 of the small square section o-rings that are also used. Clean inside the t-stat housing too. It is a 3 handed job to refit this while keeping the o-rings in place and pushing it onto the metal water pipe but you will manage it.

While you have that off, there are only 4 main bolts, the 4 bolts for the exhaust elbow flange, and some plumbing holding the exhaust manifold to the cylinder head, and it can be significantly plugged as well. You will need the main manifold gasket, exhaust elbow gasket, and more of the o-rings above once the manifold comes off. You can take the manifold home and thoroughly clean the passages and also use muriatic acid from Lowe's etc to remove deposits and corrosion. Be careful not to damage the water temp sending unit or its threaded hole, they are expensive to repair, but if you do, let me know and I'll tell you the cheap fix.

It is still possible after doing all of this that there remains corrosion or deposits inside the cylinder head or block. If after reassembly you still have the overheating, that would be the time to try circulating muriatic acid in the engine.

I would do all of the above before considering repowering. You would spend less than $200 for all the parts mentioned and I think there is a good chance of success.

Happy to answer any questions, but please confirm you have the same engine.

Michael

[sgbernd]

The cheapest and most seaworthy solution is to fix the old diesel if possible, assuming nothing is catastrophically wrong with it.

You probably have a MD7A or MD7B which, in my experience is a robust and reliable engine, but, as you have discovered, prone to heating troubles when they age. Search the archives. There is a lot posted on these and heating troubles. Then methodically start at the most likely (clogged inlet screen, scale and rust buildup in manifold, clogged passage in the inlet by the thermotsat, etc.) and work your way thru to other side (run a wire brush thru the mixing elbow). I found a drill bit, hydrochloric acid, and aggressive work with sharp screw drivers worked pretty well. The cast iron is strong and hard enough you won't damage it with some aggressive working but the rust and scale will come out.

While you may not be able to completely resolve the problem (I wasn't), you still ma get many more years of reliable service out of it (mine still runs happily if a bit hot under full load). Probably you will find lots of things that each help a bit, until suddenly it is good enough, if not perfect. Good Luck

[warrenescape]

Thanks for all the good information and helpful advice - I am due to speak to the boat yard tomorrow - on repairs vs replace - I have had both a Beta & Yanmar dealer' give me quotes for repower - not pretty. So we will see - while I am anxious to get it fixed - don't want to break the bank either - I'll keep you posted - BTW the hull number is 260 - and the engine is a Volvo MD7A - Many thanks - Warren