Beta 43 Engine, Perkins 4.108 bits….

[Chihili Q]

Last October my Perkins 4.108 broke when I repaired to the galley to serve up pasta puttanesca for my crew, failing to remind the helmsman to check the temperature gauge having also failed to open the raw water coolant stopcock (which generally I never close, but had thought I wouldn’t be sailing again that season). I had no audible or light alarm to indicate overheating, just the temperature gauge and I urge anyone in a similar position to install an audible temperature alarm without delay!
During lunch while on autohelm the engine over revved and spewed oil; at first I couldn’t turn it off; apparently such an engine may overheat to such an extent that it sucks up sump oil which serves for fuel instead of diesel and may even “explode”. I believe the answer is to stuff a cushion into the air intake but I stalled it and secured a tow to harbour, the wind having died.
I have now replaced the Perkins with a Beta Marine 43 (an opportune time with retirement due in six months) with which I am delighted; it is quieter and promises to be cleaner etc. At installation I took the opportunity of stripping out the engine bay and replacing the cockpit drain pipes with fire retardant hose and new stop cocks.
Just prior to this unfortunate incident I had bought from Electromaax a serpentine belt conversion kit and higher output 160 amp alternator, figuring that with a proficient regulator at low revs this would allow efficient charging of my battery bank. This system is now redundant since I have opted for a serpentine system on the Beta 43 with a 120 amp alternator and shall use the Balmar MC 614 regulator, bought with my conversion kit, which would however have fitted the Electromaax 160 amp alternator like a glove! If anyone would like to purchase the conversion kit at 50% of cost plus postage, with or without the alternator (which I intend to advertise on eBay shortly) I’d be happy to pass it on.
Nick Beard at Fowey Harbour Marine Engineers did a wonderful job installing the engine and is happy to remove any parts from my Perkins 4.108 for anyone, first come first served. A neighbour in Aberystwyth Marina has already availed himself of the fuel pump but if anybody would like any of the other components for a spares kit Nick would be happy to send them at cost of postage.
I cannot remember how to upload pictures but shall see if I can work it out!….

[Echopapa3]

We fitted the Beta 43 to Echo Papa last October and so far 16 hours later it has been a great addition. It replaced a Perkins 4-107 that was 43 years old. It took us a long time to change engines as the perkins was OK for getting you in and out of harbour but it was getting progressively quirky, overheating with the slightes pressure and sticking in gear as you approached the jetty. Used a manual lever on the gearbox but it was all getting like hard work. We did all the obvious stuff on the overheating and concluded it was narrowing in Heat Exchanger and BLOCK. I am sure there are folks out there that would be happy to continue to nurse it along but I want to do some serious cruisng around Scotland and Ireland this year and I wanted an engine and gearbox I can count on. Stirling Marine on the Island of Bute did the installation and I was and am very happy with it. 7 knots at
1400 revs and very little noise makes motor sailing a pleasure. Lots more power if I need it. Anyhow, will keep you posted on how it performs.

[Jeff]

EchoPapa3,
7 knots @ 1400 RPM.? Wow, I can’t get 7 knots @ ANY RPM.! What gearbox ratio did you get & what prop-size did you change to, if at all.?
Jeff

[David Phillips]

I’m joining this conversation about 10 years late, but following an incident in St George’s Channel between Wales and Ireland that resulted in a 6 1/2 hour tow from a volunteer lifeboat crew, who were dragged away from their homes for what was a 9 hour operation for them, I’m also considering replacing my Perkins 4-108 with a Beta 43 and wondering how happy people have been with these engines after such a long time.

This woeful tale is succinctly described on the RNLI website, complete with pictures – https://rnli.org/news-and-media/2025/april/08/nine-hour-yacht-rescue-for-st-davids-rnli. The incident was as undramatic as they describe. I was never in danger, but I was making only 1 knot in rolly but wind-free seas. Enough to stay out of the shipping lane, but not enough to get me anywhere. They and His Majesty’s Coastguard are professional, very relaxed, and have all the kit they need to make this sort of event ‘uneventful’. For people who are unfamiliar with the RNLI, this service is completely free and covers the whole of the UK and Ireland.

I know that the Perkins is a wonderful engine that will run forever, but I’m thinking forever might have arrived for this particular 40-something-year-old engine. I know that I could replace the failed fuel injection pump, but at best, the replacement will be an expensive reconditioned 40-something-year-old replacement. It’s also entirely possible that some other part will fail at an equally inconvenient time, and I think it’s probably my responsibility to prevent that rather than relying on the Coastguard and Lifeboat crews. I know two other boats, not Nicholsons, who have had similar issues, spent large amounts of money on parts, mechanics and visitor fees in marinas they hadn’t planned to visit. Both have curtailed their sailing plans, and neither now strays far from their home port for fear of another breakdown.

For all of those reasons, the decision has now been made. And, in consultation with sailors and mechanics alike, I have decided to get a Beta 43. I’d love to know whether those of you who have already gone down this path are still happy with your Beta? Would you still have chosen the 43 rather than the 38 or the 50? Although the 4-108 is 50 hp, I understand the original 4-107 would have been 42 hp.

[Moderator]

We still have our original Perkins 4-108. We have faced the same dilemma several times ourselves – but have always decided the opposite course. That is – find the replacement parts and keep going. Last year, we did replace our fuel injection pump with a reconditioned one – it was starting to leak at the banjo bolts. The shop rebuilt the injectors at the same time.

Our engine itself has always kept running. It’s the peripherals that have let us down. We’ve had to replace the high pressure fuel lines, fuel injection pump, fuel pickup line (make sure yours gets all the way to the bottom of the tank!), fuel shutoff cable, bleed screws, raw water pump … But everything within the block just keeps working great and so we keep feeding the beast.

I would be very curious to learn how it turned out for you replacing your engine. Are you happy with that choice? Which engine did you choose? How many other parts did you have to replace at the same time, for example, raw water cooling circuit, water lift muffler, gearbox, prop shaft and prop? Does everything need to be changed to match the power capabilities and fuel/air requirements of the new engine?

Thanks – Marilyn

[Kev]

I’m looking at a 36hp engine is this enough power for a Nicholson 38 or do I need bigger?? Pic is happy dolphin

[David Phillips]

Hi Kev,

This was my question (and concern). I wanted to replace a 50 hp engine, and lots of people were scratching their heads and saying I didn’t need an engine that big, I didn’t need to spend that much money, or that I didn’t need to buy a new engine at all. As Marilyn’s post above demonstrates, some people can make the engine last forever. I don’t think I’m one of those people. I’m not sufficiently mechanically minded to be confident sailing significant distances with this old engine.

I was also worried that the advice about engine sizes was more about saving money rather than sizing the engine properly, so I was very pleased to have found this thread with other people having previously gone down the same path as me. Possibly because they had read this article about sizing an engine on Beta Marine’s website.

I was also pleased to discover the original engine would have been 42 HP (unless anybody knows better). I would be interested to know which manufacturer you’re thinking of?

Best wishes (and good luck),

David

[David Phillips]

Hi Marilyn,

I’m suddenly doubting myself. You refer to your 4.108 as the original engine. I thought the 4.107 was the original engine, and the 4.108 must therefore be the second engine in my boat. Caol Ila is Hull No. 22 and launched in 1969, so it is a reasonably early boat. Maybe the earlier and later boats had different engines. Or, maybe, I’m just wrong?

[Moderator]

As I understand it, the early hulls had a 4-107. Later hulls had the 4-108.

Rainshadow is hull #126 from 1974 and began with a 4-108. Not sure when the change was made.

Another difference I’ve noticed about people’s comments on engines
– Rainshadow has a Sherwood G65 raw water pump. I think it is more common that the 4-108 has a Jabsco water pump.
– Rainshadow has a front mounted heat exchanger. I’ve seen photos of other people’s Nic-38 that have the Bowman heat exchanger at the exhaust manifold.

Marilyn, moderator

[Author]

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