New boat running slow

Plymsea

Plymsea

Member
Joined
12 Aug 2020
Messages
37
Location
Plymouth UK
www.brayesea.com
Hi all, I have been reading the fora for a while and found them a great resource. But cant find anything on this topic, so here goes....

Just bought a 26' Westerley, seems in great condition for her 1973 vintage and love the roominess!

The engine is a 23HP Beta and runs nicely but has little impact on progress through the water, flat out 3k RPM and 1.5kn. Have not got the sails set up properly yet, so not tested under canvas.

She has been kept on a tidal river, there are no visible signs of weed but my first thought is that the hull, prop or both are heavily fouled. So drying her out and having a look is job 1, but keen to know if anyone has suggestions as to what else to look for?

I would have expected the engine to comfortably manage 4kn.

Thanks in advance for any pointers.
 
I would expect a 26' boat with 23hp to plane, well, almost. I'd go for gross prop fouling. Even a small amount will knock 3/4 knots off my boat's motoring. If that is not the case, it may be the engine, but 3k revs sounds healthy.
 
I but a Meta Marine 13.5 into a 27 Ft trapper 500 some years ago and it would cruse at 5.5 kn at 2200 revs.
I wonder have you a folding pro that is fouled and not opening properly.
Has she a damaged prop?
maybe you have an old rope or plastic bag wrapped on the prop. I had a woven plastic sack wrap itself around my prop last year and it halved the the drive speed.
Or something may be slipping as suggested. How does she go in reverse? Is there any difference in the power output?

Kinsale 373
 
Our just sold westerly pentland, 31 ft but much the same hull shape as centaur 26ft, did obout 6.4kt in calm water on a 25/28hp so you should get comfortably over 5kt with 23hp on a 26ft. Chop will slow you but you should make 5kt unless banging into headwind.

So something wrong.

On the other hand our LM27 went from 5kt to 3.5kt due to over winter fouling in River tamar and much better after we removed the 2 inch thick mussel bed with resident crabs. We got caught out as upper bristol channel mud berths for our Westerly only get a barnacles. LM27 now does just under 6kt on re-engine to 24hp and shes a tubby thing with less sleek lines even than an early Westerly

So where was the OPs boat kept? Is heavy fouling likely?

Does the OPs boat rev up to at least 2500rpm ?

If reving ok and no fouling, I fear undersized prop or damaged/fouled prop.

If not that more likely bad cone clutch slip. If revs increase and its makes little difference to speed at upper mid range, or it takes time to get properly into gear and move away thats what Id most suspect.

However I got similar symptoms due to poor clamp on prop shaft after rebuild. Gear box was turning but prop shaft not as fast. Lucky I didnt damage things but quick spanner, allen key work in the entrance to Cardiff barrage sorted it. But this symptom would only be transient before complete failure
 
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Something very wrong, I get about 5.5kt from my 13HP Beta in my Sadler 25 at just under 3000 revs,, my previous boat an Invicta26 had a Beta 10 and would easily reach 6kt.
Sounds like a prop' problem, hopefully not gearbox trouble.
 
My 24 footer gets hull speed at about 3/4throttle from 13hp. My last 26 footer had plenty of power from a 20hp Bukh, so theres definitely something wrong. Firstly if the boat is badly fouled, chances are the log is well under reading? Bad weed fouling might knock 2 - 3 knots, but not down to 1.5kts unless its exceptional (and probably visible!). You can get 3000rpm at the engine, which means its unlikely to be overloaded, but is the shaft turning fast? (prob around 1500rpm) If its only going slowly then its a gearbox/transmission problem. If it is turning, then theres a problem with the prop. Damage, fouling, sheared key etc. A mini waterproof video camera cheap off fleabay might give you some idea of whats not happening if drying out is an issue! But you will have to dry out anyway to sort anything external!
 
[QUOTE.
Just bought a 26' Westerley, seems in great condition for her 1973 vintage and love the roominess!

The engine is a 23HP Beta and runs nicely but has little impact on progress through the water, flat out 3k RPM and 1.5kn. .
[/QUOTE]
Pedant alert! Just to avoid future confusion, Beta don't do 23 HP, it's either 20 or 25 (unless there's one that goes back to earlier times).
 
Welcome to the forums. Like others I suspect a heavily fouled propeller. If you can safely get into the water with the boat tied alongside and the engine off you should be able to look at the prop and see if it is badly fouled. It does not take much fouling to ruin the efficiency of a propeller. Your best bet may be to find out where you can safely dry out at low tide. If its a twin keeled Centaur it will happily sit on the ground and you can clean the prop, and check or replace its anode before you float off again.
 
Welcome to the forum and becoming a boat owner.

My thought is are you sure your boat is only doing 3 knots. If the log is fouled then it will grossly under read. Your Centaur should be able to motor at 4½ to 5 knots - a fast walking speed. If it does not seem right then I do suspect the propellor is either fouled with barnacles or something like a rope or polythene wrapped around it. The final one is it has the wrong size propellor fitted. Beta will be able to advise on what should be fitted and you will find the propellor will have the size stamped on it.

My final advice is to join the Westerly Owners Association (£15. p.a.) and the WOA forum (free).
– Stay safe! Your 3128 friends at WOA
https://westerly-owners.co.uk/peepso-activity/
 
Thanks for all the great responses so far! :)

And the warm welcome. Have already tagged the WOA and heard they are a helpful bunch too.

Like Oldmanofthehills the boat was on the Tamar so heavy fouling looks like a very good possibility! Another indicator for this is that there is plenty of water moving around aft when in gear.

The boat was definitely making slow headway, not a log issue.

Reverse works about as well as forwards and both select smoothly and without delay, so fingers crossed on the gearbox side of things. Also there is no undue noise/vibration so a sheared key does not seem too much of an option.

I stand corrected on the HP, boat originally had a 23HP but this was replaced with the 20HP version.

Plan is still to dry her out and have a look/scrape/cut etc. Was going to dive but SWMBO put the brakes on that plan.

Thanks again all
 
You know crime is on the increase due to covid.
I reckon someone's nicked your prop. :)
Joking apart- if the prop shaft is spinning at the stern tube then it's got to be a prop problem as said before.
 
I was given a cheapo waterproof video camera. It has been very useful on a few occasions, lowered alongside the prop on a cord. Local water is a bit murky but I have got usable pictures, just about. There are places with clearer water, such as Goldhanger creek, if you look around.
 
Greeny, the prop is definitely doing something - there is a lot of water moving but not as coherent thrust. The water here is a balmy 17-12ºC at the mo! :)

Johnalinson, genius! I have a waterproof bore-cam that is easily long enough to get a look - thats now my first job tomorrow :D
 
It may not be just the prop that's fouled. In the first year we had Osprey (our first, and so far only, boat) she just got slower and slower , until she would barely get over 2 knots under either sail or engine. She had been on a swinging morning for lord knows how long pre-sale. I went to have a look with a mask and snorkel and found that not only could I not see the propeller due to the huge amounts of growth around where it (presumably) was, the whole underside of the boat was towing what looked like a long furry carpet around.
 
PS - if you do dive down, even if just to have a look, wear gloves and long sleeves (or a wetsuit). Barnacles are bloody sharp and will rip your skin up nastily even on a glancing touch.
 
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