Need advice on Princess problems

[Guest]

I'm trying to sort out a couple of problems over this winter - and I need some advice. The boat in question is a (much loved) Princess 37 with twin Mermaid 175 Turbodiesels.

(i) Low Top Speed - Underway it's pretty much impossible to get it over 15 knots. At this, the engines are revving at about 1500 rpm. In neutral the engines rev clean out to about 2500 rpm, and at that speed I can hear the Turbos whine - but I see no boost at all on the Turbo boost gauges.

(ii) LOADS of smoke at start up. Both engines - plenty of grey smoke when I start them up. It goes away when they get heated up a bit - but it's a nightmare in the Marina.

OK - so I know I can cure both problems by replacing the engines - but that's a bit extreme as a starting point. I don't really want to spend 12 or 14 grand on new engines unless I really have to - at the same time, I don't want to spend 2 or 3 grand on things which only MIGHT solve the problems.... (know what I mean ?)

The engines appear to be ok. They don't use engine oil - and the oil is in good condition - no signs of milkiness. They start readily from hot or cold (obvioulsy very cold starts require excess fuel, and a couple of turns).

One marine engineer has suggeted that a change of props will help, and the props fitted are 'economical' . Does anybody know what the correct props for this boat should be ? Obviously this wont help problem (ii) though....

I wondered if the both problems might be related to the Turbos - and whether I should have them reconditioned. It seemed odd to me that I didn't see any boost when the engines were revving flat out - and I wondered if they could be seeping oil into the inlet manifold (and on into the engine) when they were cold - thus causing the smoke.. but would would worn turbo producce less boost ? - Maybe if they weren't spinning fast enough ?

Problem (iii)

Trim Tabs - the boat is fitted with tabs branded 'Seaflaps' - I have lots of problems with these - the ram seals are leaking, so it loses a lot of it's fluid, the actuators ob the fly bridge (push button) don't work any more, and the actuator from the wheelhouse (i presume wasa joystick) is missing (as in gone away somewhere) - does anybody know if parts for this brand are still available - or should I just replce the whole system ??

& (iv) (probably related)

In certain choppy seas, at low speeds (note problem 1) the boat bobbs about quite a bit. My suspicion is that this could be improved if the trim tabs were actually working. This was particularly bad on our last outing in October - however we had just filled up the diesel tanks for the winter, so she was carrying a lot of weight to the stern. On returning to the Marina I did notice that the boat was actually lying to the stern a bit - the exhaust outlets were below the water level. The paintline was just about at tthe waterline on the stern, but quite high on the bow. The bilges are dry, so there isn't any water weighing the stern. So my question is is this attitude normal - and will the trim tabs improve the ride - or should I also try and trim the boat with some ballast to bring the bow down ??

All info/advice gratefully received...... either to this forum or direct to louisc@tinet.ie.

Would also like to hear from other Princess37 owners to compare experiences/stories etc




louis

 

[miket]

From memory Princess 37 either had small engines 120hp (usually in Y hull - displacement) or 180 or 210 hp Mermaids in Planing hull.

If yours is displacement (no spray rails showing at front, only the turned up chine) I think you have done well to get 15 kts. If planing you have a problem.

I would attack in this order:
1. Trim tabs - as you are light on hp, the tabs are more important. Sort these first.
2. Props - check these. (CJR propulsion will run it through their model) You will need: Length waterline, beam waterline, max design revs, unladen & laden weight, hull design speed (max')
3. Smoke - normal at start up. All Ford based engines of this era are same.
4. Engines - Speak to Mermaid - a. what is designed max rev's? b. Is it possible to tweak your engines up to higher hp rating? Mermaids are usually very helpful. Ask to speak to their technical department.
5. Ride - if marginal on power/ speed, will tend to wallow. Tabs working may help to lift stern and add extra few knots.
6. Bow up at rest - Do you have heavy RIB on transom davits? Do you have a lot in your lazarette (under rear cockpit floor) Where is water tank and was it empty?
All these will contribute to bow up and difficulty in lifting stern at speed.

Hope this helps.
Godd solid boats.

 

[longjohnsilver]

Smoke is normal for those engines. Don't know about the trim tabs.
The engines should pull up to full revs, probably the props or fouling, is the problem the same when just launched?

I know that Mermaids have a good knowledge of your boat and engine combination. Suggest you phpne thsm and ask to speak to Steven, Chris or Cyril - tel 01202 891824. They are very pleasant and helpful.

Let us know how you get on.

 

[hlb]

Doubt if theres very much wrong. 15 knots sounds about right for a 37. Clean bottom and mend the trim tabs will help a bit, but otherwise it sounds fairly normal.

Haydn

 

[longjohnsilver]

Ah but haydn, there must be something wrong if 1000 revs down on maximum. If this is so then should have loads of black smoke when trying to pull full revs.

 

[oldgit]

Re:Weed ? NM.

?

 

[longjohnsilver]

Re:Weed ? NM.

Please don't call me a weed, I'm not really!!! Come to think of it I'm not even any sort of plant, most of my mates call me a brick, or they say I'm *something* as a brick, but they always whisper the first word so I can't hear.

Am I missing something??

 

[david_bagshaw]

Blocked air filter?

Blocked fuel filter?

no boost pressure sensor pipe connected / blocked at injection pump?

If engine only reaches 1500 & no black smoke it very much suggests either 2 or 3

Hope this helps

David
www.yachtman.co.uk

 

[mike_kolling]

Definitely sounds like you are overpropped, should get 2500 rpm out of these engines.
I have got the original spec sheet from princess at home (as I own a 37 with 120s)
I will dig it out tonight and get back to you tomorrow as it has the exact propsize that Princess originally supplied it with.
If you email me direct with your fax number I can fax it to you.
Fouling on the bottom will also reduce speed by 15%.
As the other guys have said, most of the ones I know of only get approx 16Knots out of 180s. I get 11K out of my 120s.

best regards
Mike
Where are you based, we are on the Thames?

 

[byron]

Re:Weed ? NM.

What has urinating got to do with anything?

ô¿ô

 

[hlb]

No need be nothing wrong. Try running on one engine and see if you get full revs. Revs go up with boat speed cos faster boat goes, makes it easier for props to go round.

It might have mucky filters and alsorts wrong. I dont know, sat on my arse here.

But clean the bottom and have ago again.

Last spring I jumped on my boat just after it had gone back in water. It shot up to 25 knots with engines reving wildly. I thinks, bloody hell and slows down a bit.
Gets September and its full throttle and 18 knots and about 5000 revs short.

Haydn

 

[Guest]

Can't be 5000 rpm short haydn, youve got too many oooooooo probably like youre bank balance!

Paul js.

 

[Guest]

These old mermaids always smoke so start up no probs, is she on the south coast as I have looked at many 37's when I was looking to buy one.
If the engines rev in neutral, flat out you should get 2600, if not then alter throttle lever on pump, check that cable is puling pump to max position.
Turbos dont kick in till sbout 1600 rpm, so you wont see any boost although gauges are electric so check terminals wires etc., you wont get any boost out of gear only when engines are under load, prop I think are 3 bladed 19/17 but thats a guess from memory.
Change all filters and check for air leaks at joints, this boat by any chance has had a BSS certificate because sometimes the wrong bore flexi pipes can be fitted, see me post further back about BSS ranting on etc.
Do you get black smoke under load, you should if the turbos are not working correctly, this shows that the engines are getting fuel.

Check injection timing, too much white smoke is retarded pump timing.
Last resort will be strip down injectors and pump removal for recalibration, set timing etc, test compressions to check if pistons etc are ok.

Send me a private email if you like for my phone no.

Paul js.

 

[hlb]

Ok,so I'm prone to exaggerate! Well, its lots and lots.
Are you some sort of perfectionist?
Whats an odd 0 between friends anyway.

Haydn

 

[ArthurWood]

Similar prob today: set out to head 50nm S to our fav island. Got out of marina and into Sarasota Bay, wound up the throttles and boat just about climbed on plane. Realised had had bottom/running gear cleaned month ago, had been out once since but stuff grows fast on props here. Said %&)/$# and turned back into F3. SWMBO upset cos spray came over her (no flybridge) and because she had been looking forward to nice 3-day trip.
Told her think herself lucky she's not boating over there. Not amused. Back in marina I umed and ahed about putting on wetsuit and going under to clean props, but water only 16C, so had beer instead. Called diver to come tomorrow.

 

[Guest]

Wow - what a lot of replies - thanks for being such a helpful bunch of sailors.

I'm at home now, and have looked up some boat related docs - it appears that the props fitted to her are 20 X 22 X 3 - which is bigger that suggested by one of the replies - I'll check that with Princess.

Small correction - the engines are rated at 180 hp - not 175 as I originally stated - and I presume its the V hull - because of the engines. I'm not sure how I'd know without having seen both versions. It has a flybridge - was the Y hull built witha flybridge option ?

I expect the bottom was reasonably clean, no more than 6 months since an antifoul.

I'll also be changing the fuel filters as part of the winter duties so that will be ruled out - the boat, interestingly enough doesn't have airfilters - the turbos draw air directly through a coarse wire mesh in the inlet throat - I guess dust isn't usually a problem at sea (but is that really so in the Med at certain times ? - well it's not an issue for me - as the boat is based in Ireland - now dust at sea is definitely not a problem here!)

Re whether it's blowing black smoke underway - I can't say that I've noticed that so much - but I definitely noticed that the transom is being blackened by the exhaust, as I've had to wash it off several times this year - so that could be a pointer....


And on to the seakeeping/attitude & trim tab issues:

The lazarette is empty except for a 5hp Yamaha outboard - and while the boat does have davits - the tender is a light inflatable. However the diesel tanks are mounted in the lazarette and are both full - so I guess that's possibly in the region of 150 gals each. The water tanks are further fwd - and are less than half empty - I've no doubt that this is contributing to the attitude - but should I contribute this much - and should I trim with ballast to compensate ?

I'd like to get the tabs sorted - but have no idea where to begin looking for parts.

thanks again for all the help - it's much appreciated!


louis

 

[longjohnsilver]

Mermaids didn't fit air filters, as you say probably not needed. If it was your fuel filter causing the problem the engines would run to max revs for a short while and then splutter, so although changing them is good practice almost certainly they are not the problem. Also your hull will be the V version - no point fitting your engines to a Y hull. Also if it was blowing black smoke you wouldn't miss it. Dirt from the exhaust is normal on almost any boat.

You say 6 months since antifoul, thare could be a lot of fouling in that time, well worth checking as this would make a big difference.

 

[miket]

At Shamrock Quay, Southampton, 6 months fouling on a boat with marginal reserves of power and innoperative trim tabs would be terminal.

Check the prop size whilst she is out of water.

 

[ArthurWood]

If the boat has been in the water for 6 mo. check for prop fouling. As indicated above I had v. similar symptoms yesterday (petrol engines) after 1 mo., ie only 3200rpm vs normal 4200 max.

Question for the BB experts: do I understand that you only clean your props once per year in the UK/Med? Don't you have a gradual but pronounced performance degradation over time or is fouling less of a problem with hi-torque diesels vs petrol engines?

 

[Guest]

Props sound far too big but IMHO.

Paul js.