<![CDATA[Cruisers & Sailing Forums - Engines and Propulsion Systems]]> https://www.cruisersforum.com/forums/ Gas, diesel, hybrid and electric en Thu, 30 Apr 2026 02:59:50 GMT vBulletin 60 https://www.cruisersforum.com/forums/images/misc/rss.jpg <![CDATA[Cruisers & Sailing Forums - Engines and Propulsion Systems]]> https://www.cruisersforum.com/forums/ Help! Yanmar fuel lift pump bad?? https://www.cruisersforum.com/forums/f54/help-yanmar-fuel-lift-pump-bad-299992.html Wed, 29 Apr 2026 19:25:38 GMT Stuck in harbor. Looking for advice. Here is the situation: -New-to-us sailboat. Yanmar 4JH4AE diesel. 700 hours, or so the panel says.... Stuck in harbor. Looking for advice.

Here is the situation:

-New-to-us sailboat. Yanmar 4JH4AE diesel. 700 hours, or so the panel says.
-Diesel was leaking oil (I am near certain) out of the front main seal. Not bad but leaking.
-Replaced it (3 days to move plumbing and wiring out of the way so I could cut a large access hole in the bulkhead right in front of the engine, 2 hours to replace seal. Why the builder of the boat did not consider access to the front of the engine critical I have no idea—but that’s a question for another day).
-Drained and replaced engine oil.
-Test run engine. No leak that I could see.
-Started our trip down the US east coast
-Checked the engine, including oil level, several times over the first few days. No problem.
-Went into the engine room to check something else as we were motoring all day. Oil spattered all over the place. Looked like again coming from the front seal.
-Immediately shut down engine.
-Checked oil level. WAAAAY high. Way. Several inches ABOVE high mark. Oil looks clean and nice. Not milky or issues.
-Sailed into harbor, where I now sit.

My theory: Fuel life pump went bad, allowing diesel to get into the oil. Also caused the brand new front seal to fail, throwing out the oil/fuel.

Ideas? Opinions??

Thank you! ]]> Engines and Propulsion Systems Phish https://www.cruisersforum.com/forums/f54/help-yanmar-fuel-lift-pump-bad-299992.html Engine and Gearbox Control Cables https://www.cruisersforum.com/forums/f54/engine-and-gearbox-control-cables-299989.html Wed, 29 Apr 2026 16:55:25 GMT I had a misadventure with my engine control which resulted in some drama, fortunately damage-free, in one harbor as I was trying to dock. I now... I had a misadventure with my engine control which resulted in some drama, fortunately damage-free, in one harbor as I was trying to dock.

I now finally have the spare parts to do a permanent fix, but now I'm thinking about the control cables.

They are over 4000 hours old so surely time for some maintenance, or replacement. They have been working fine and never noticed a problem until the connecting part broke recently.

How often do you guys replace them?

Do you lubricate them? How?

I note that you can buy "cable lubrication tools" in different places, used by motorcyclists.

Grateful for tips. ]]> Engines and Propulsion Systems Dockhead https://www.cruisersforum.com/forums/f54/engine-and-gearbox-control-cables-299989.html 4JH3E-HTE Alt mount hole wallowed https://www.cruisersforum.com/forums/f54/4jh3e-hte-alt-mount-hole-wallowed-299969.html Mon, 27 Apr 2026 21:25:31 GMT Good Day All! Have an issue with the mounting hole on the gear case for the saddle mount alternator on a 4JH3E-HTE. A previous bad install left... Good Day All!


Have an issue with the mounting hole on the gear case for the saddle mount alternator on a 4JH3E-HTE. A previous bad install left the hole wallowed out. I was wondering if anyone had a good solution / fix for this. It was overlooked during our engine overhaul by the shop. We are running a high-amp alternator with a balmar serpentine pulley kit now and last season it slipped into the wallow and caused the ear on the saddle mount to bend and then break.


The hole was filled with JB Weld, tapped and so far so good but we don't like that as a final solution.


Open to suggestions
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]]> Engines and Propulsion Systems Capt.Go https://www.cruisersforum.com/forums/f54/4jh3e-hte-alt-mount-hole-wallowed-299969.html Can’t find a dang airleak!!! https://www.cruisersforum.com/forums/f54/can-t-find-a-dang-airleak-299963.html Mon, 27 Apr 2026 15:48:56 GMT Hi! I’m a girly with a sailboat and getting overwhelmed with an engine problem please help!!! I’ve spent a few days trying and kinda gotten to the... Hi! I’m a girly with a sailboat and getting overwhelmed with an engine problem please help!!!

I’ve spent a few days trying and kinda gotten to the end of what I know how to do myself. I have a universal Westerbeke m18 diesel engine it’s 2 cylinder.

So the facts in the case:

I have an air leak that I cannot find for the life of me!!! When I bleed from my injectors there’s non stop bubbles. When I bleed from the bleed screw on my fuel filter sometimes it can take a min for the fuel to start coming but it will be bubble free when it does come. Which makes me think the leak is between fuel filter and injectors but idk. I can get it to start sometimes but it’ll die again shortly after. All the normal things didn’t work so I just started trying everything.

I Changed my Racor filter and fuel filter and I even changed my 12 v fuel pump and none that work. It’s not an issue at the tank because I took the fuel hose from the tank and put it in a cup of diesel and was still getting bubbles. I replaced the small fuel hoses that go from the fuel filter to the injectors with brand new hose and still bubbles. I only had a small piece of my bigger hose but I used it to replace each section of fuel hose in the rest of the system from the tank onward one at a time and tested it each time I replaced a section to see if anything changed each time and I would still get bubbles at the injector fuel bleeds each time. I took the filters off and on to make sure they were sealing and they appeared to be sealing just fine.

another fact about this case is a few days before my engine started dying I did notice my injectors weren’t fully tight and I actually could see diesel bubbling out of them ((like out of where the injector is seated into the engine I’m not talking about from the injector bleed screw here)) so that was the first repair I thought to do is reset them. I took them out and cleaned everything but the problem is I couldn’t find the exact injector washers my Manuel asks for to replace the ones that came out but a mechanic gave me a washer of the same size and said it would work fine for this so I put it in there for now ((got the right one ordered already tho to replace)) and torqued it to the correct setting and didn’t see the bubbles from where the injectors were seated anymore but there were still bubbles when I cracked the bleed screw and my engine was still dying after this repair so not sure if that’s cause it’s still related to the washer or not.

I also noticed that in some places in my system the fuel hose slipped on the nipples a little more easy than other places. I’m wondering if maybe that’s not normal and if they’re supposed to be a tight to get on and air is slipping in and I should downsize but still doesn’t make sense as to why it’s run fine up till now but now all of a sudden keeps dying frequently. The metal injector lines themselves I didn’t notice any leaks when I sprayed soapy water on them but could be hard to tell. Oh and don’t think my alternator is charging my batteries right now seems like I’m only charging from my solar idk if that’s relevant but just throwing that in here.

Anyways that’s so much information but I’m struggling man, if anyone has any leads or ideas that could help me Id greatly appreciate it!

*forgot to take a pic of them bubbling but when these screws are loosened this is where I see all the air bubbles come out from ]]> Engines and Propulsion Systems Clairebear https://www.cruisersforum.com/forums/f54/can-t-find-a-dang-airleak-299963.html Yanmar 3GM30F exhaust mixing elbow https://www.cruisersforum.com/forums/f54/yanmar-3gm30f-exhaust-mixing-elbow-299950.html Sun, 26 Apr 2026 16:07:16 GMT I am replacing my mixing elbow and have a couple of questions I am hoping someone may have an answer to. Firstly the existing elbow used spring... I am replacing my mixing elbow and have a couple of questions I am hoping someone may have an answer to. Firstly the existing elbow used spring washers instead of flat washers on the bolts. Is this normal and sensible, or should I replace with flat washers?

Secondly, how tight should the M8 bolts be? The torque is not mentioned in the Yanmar service manual.

Any other hints and tips would be welcome. ]]> Engines and Propulsion Systems Sailing Paul https://www.cruisersforum.com/forums/f54/yanmar-3gm30f-exhaust-mixing-elbow-299950.html <![CDATA[First boat with traditional Diesel inboard. Maintenance basics & tools. Read 1st post]]> https://www.cruisersforum.com/forums/f54/first-boat-with-traditional-diesel-inboard-maintenance-basics-and-tools-read-1st-post-299927.html Sat, 25 Apr 2026 03:51:44 GMT Hi,


we have our first boat with Diesel inboards.


Two, a bit aged, but recently overhauled Perkins Perama M35.
I'm told in itself they are relative simple (non electronic) engines.


Please don't get hung up on if they are good or bad engines.
They are what we have.


Hürth 100 gearboxes.


Traditional shaft lines, ceramic face seal style shaft seal.


We live aboard and I'm wondering, what are the basics we need to know to keep them well and not in need for a mechanic in the near future.


We aim to do most things ourselves.


So what skills should we focus on to aquire, what tools and spares are the most important ones we should get?


What are essential engine emergency procedures we need to know?
I know of the air intake blocking in case of a run away, but not much more..


Thanks. ]]> Engines and Propulsion Systems Catamarangirl https://www.cruisersforum.com/forums/f54/first-boat-with-traditional-diesel-inboard-maintenance-basics-and-tools-read-1st-post-299927.html Yanmar SB8 Engine stalls https://www.cruisersforum.com/forums/f54/yanmar-sb8-engine-stalls-299869.html Tue, 21 Apr 2026 20:20:50 GMT Hello everyone, I am new to boat ownership, having recently acquired a Tomahawk 25, which came with the original Yanmar SB8 engine from the mid... Hello everyone,
I am new to boat ownership, having recently acquired a Tomahawk 25, which came with the original Yanmar SB8 engine from the mid 70's.
My problem, is that whenever the engine has been running for a while, when I go back into neutral, it just dies. Similarly when I try to shift into reverse. After this, it takes a good few seconds of cranking at full throttle before it will start again.
My thoughts are that it is something to do with the pump, but does anyone have any insight that could help me overcome this problem.
I have done some searching through the site, but could not find this specific problem.
Many thanks from a complete newbie. ]]> Engines and Propulsion Systems iowgav https://www.cruisersforum.com/forums/f54/yanmar-sb8-engine-stalls-299869.html VP 2003 - Circulation Pump https://www.cruisersforum.com/forums/f54/vp-2003-circulation-pump-299864.html Tue, 21 Apr 2026 18:22:11 GMT After rebuilding the circulation pump(new seals , shaft, gasket etc.) on my VP 2003(fresh water cooling) and 2-3 hours all was fine including the... After rebuilding the circulation pump(new seals , shaft, gasket etc.) on my VP 2003(fresh water cooling) and 2-3 hours all was fine including the water heater was heating water normally and the engine was working normally suddenly whne I started it today after 30 minute of working teh engine overheated!!!! The house to the water heater ware cold and the heat exchanger was cold e.g. this point to not working circulation pump, the belt is oK and the pump is turning ... e.g. now it looks like something is wrong with the pump either the propeller in the pump is nor turning for some reason or something else ...

Any suggestion how to diagnose more in details without taking the pump out ???

As taking it to pieces etc. as the whole process of removing and refitting the pump is a nightmare to arrange all the bloody pipes and seals and fix all the potential leaks ..... ]]> Engines and Propulsion Systems vtomanov https://www.cruisersforum.com/forums/f54/vp-2003-circulation-pump-299864.html Two-stroke rotary exhaust valve (REV) engines https://www.cruisersforum.com/forums/f54/two-stroke-rotary-exhaust-valve-rev-engines-299817.html Sat, 18 Apr 2026 23:34:25 GMT I just saw this on YouTube about an ingenious new two-stroke engine design that is not yet in production. According to the presentation, it can... I just saw this on YouTube about an ingenious new two-stroke engine design that is not yet in production.

According to the presentation, it can burn gasoline, heavy fuels, CNG, or even hydrogen equally well, and can switch between them on the fly.

The video is very well produced, with the usual explanations of 4-stroke vs. 2-stroke and their disadvantages, which everyone here likely already understands. The explanation of the actual REV engine begins at about 11:26 into the video.

The Engine of Our Dreams Exists. It's a Clean, Powerful, Supercharged and Rotary Valved Two Stroke
https://www.youtube.com/watch?v=5czHDU6pK8E

It's not yet in production, but I think it has great potential for marine applications.

I think that for diesel it would be best to have the fuel injector in the cylinder head instead of in the intake.

Your opinions? ]]> Engines and Propulsion Systems Michigan_Eric https://www.cruisersforum.com/forums/f54/two-stroke-rotary-exhaust-valve-rev-engines-299817.html SD20 saildrive part https://www.cruisersforum.com/forums/f54/sd20-saildrive-part-299813.html Sat, 18 Apr 2026 13:40:43 GMT Hi , Does anyone of you know the dimensions of the circlip (spacer) that is between two seals on prop shaft? Part number is 196315-02880 circlip... Hi ,
Does anyone of you know the dimensions of the circlip (spacer) that is between two seals on prop shaft? Part number is 196315-02880 circlip needle 52

Thanks ]]> Engines and Propulsion Systems Milos https://www.cruisersforum.com/forums/f54/sd20-saildrive-part-299813.html Lewmar/Whitlock Single Engine Control Broken https://www.cruisersforum.com/forums/f54/lewmar-whitlock-single-engine-control-broken-299777.html Thu, 16 Apr 2026 12:50:20 GMT This happened to me just as I was manuevering into a berth: Attachment 309743... This happened to me just as I was manuevering into a berth:


Attachment 309743

Attachment 309744

Attachment 309745


That was interesting! The situation was resolved without damage, miraculously, but that's another story.


The question is whether I should wait two weeks to get that Lewmar/Whitlock part, or whether I should try to have a more robust part machined.


In either case, I believe it would be good to replace the cables.


I was horrified to see that what can be a life or death control depends on a tiny plastic part like the one depicted. I could have something more robust, machined out of alu or SS.


On the other hand, the original part lasted 25 years.


What do you guys think?
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]]> Engines and Propulsion Systems Dockhead https://www.cruisersforum.com/forums/f54/lewmar-whitlock-single-engine-control-broken-299777.html Anyone added a Fuel Flow Monitoring System to older diesel eng? https://www.cruisersforum.com/forums/f54/anyone-added-a-fuel-flow-monitoring-system-to-older-diesel-eng-299762.html Wed, 15 Apr 2026 17:32:25 GMT I have a 1993 Yanmar 4JH2-TE, all mechanical. Id like to be able to monitor fuel flow more accurately, but it seems like with fuel flow about 1 gph... I have a 1993 Yanmar 4JH2-TE, all mechanical. Id like to be able to monitor fuel flow more accurately, but it seems like with fuel flow about 1 gph its on the very bottom end of the range that most commercial add-on fuel monitors operate. I question if it will be accurate if its on the edge of its operating range.

Something like this Maretron FFM100 unit- https://www.hodgesmarine.com/marffm1...BoCqmkQAvD_BwE

I would be interested to hear from anyone that has done this mod and what unit was used.

Is it neccessary, no. Would I like to have it, sure. ]]> Engines and Propulsion Systems CrispyCringle https://www.cruisersforum.com/forums/f54/anyone-added-a-fuel-flow-monitoring-system-to-older-diesel-eng-299762.html Oil for Volvo saildrive https://www.cruisersforum.com/forums/f54/oil-for-volvo-saildrive-299754.html Wed, 15 Apr 2026 13:29:45 GMT I have an ancient Volvo 110S sail drive and want to replace the oil. The manual recommends using CD oil with a SAE 20W viscosity. Pretty much... I have an ancient Volvo 110S sail drive and want to replace the oil. The manual recommends using CD oil with a SAE 20W viscosity. Pretty much impossible to buy single weight oil. Which multi-weight oil makes most sense? Apparently viscosity matters with these units. ]]> Engines and Propulsion Systems AiniA https://www.cruisersforum.com/forums/f54/oil-for-volvo-saildrive-299754.html Teflon packing, who would thunk,… :-) https://www.cruisersforum.com/forums/f54/teflon-packing-who-would-thunk-299724.html Tue, 14 Apr 2026 06:31:11 GMT So I replaced the stuffing box with a new one on my 38ft. Blue water cruiser . I packed it with normal packing with a layer of teflon impregnated... So I replaced the stuffing box with a new one on my 38ft. Blue water cruiser . I packed it with normal packing with a layer of teflon impregnated packing in the middle. Have sailed and motored this baby for 28years now since then. A few times I’ve opened it and checked the shaft and bronze to make sure it’s all good. Sometimes it drips. some times it’s just damp on the shaft, never warm or hot. I’m very thankful it has been doing its job so faithfully and reliably for so many, many miles and years with no issues. Knocking on wood.
Andy
SV Soy Libre
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]]> Engines and Propulsion Systems akopac https://www.cruisersforum.com/forums/f54/teflon-packing-who-would-thunk-299724.html D2-55 - Copper oxide corrosion on surface of raw water stopcock https://www.cruisersforum.com/forums/f54/d2-55-copper-oxide-corrosion-on-surface-of-raw-water-stopcock-299718.html Mon, 13 Apr 2026 23:25:25 GMT Hi all Just commissioning the boat for this season. I noted strong copper oxide corrosion on the adapter directly connected to the raw water... Hi all


Just commissioning the boat for this season. I noted strong copper oxide corrosion on the adapter directly connected to the raw water stopcock from the saildrive.


I think I have a few options:


1. Ignore it, its a boat, it'll be fine.
2. Clean it up, and keep an eye on it over the following months
3. Replace the brass(?) adaptor
4 Replace the adaptor and stopcock
5. Nuke it from orbit, it's our only hope!


Currently, I think option 2 is what I would do. The saildrive zincs were replaced toward the end of last year. There is no sign of water ingress. We lived aboard for a cold winter 2024/25, so there was likely condensation that caused this. Keep an eye on it, and be ready to replace it next haulout.


Any advice much appreciated!


]]> Engines and Propulsion Systems BirdBrain https://www.cruisersforum.com/forums/f54/d2-55-copper-oxide-corrosion-on-surface-of-raw-water-stopcock-299718.html