moiuk

Thanks 👍

It's has 712/2 written on it..

Thank you. Getting things together to do this. Watching videos on how to reprime the fuel after changing the filters, obtaining a few large containers for the old fuel and trying to work out which new fuel filter to purchase.. Thanks for all the appreciated help. Will update after I have completed the cleaning...

Okay. I'll drain off a good amount and put that into a glass bottle to see how that looks to compare against the sample I took from the bottom of the tank.. On the left is the sample taken from the water trap and on the right the fuel taken from the tank yesterday.

So I just tried to drain the water trap by opening the tap underneath. Obviously I have a lot of water in my fuel, how how does it work normally? Will the tap under the water trap only capture the water so I drain it until it stops, or will it keep going effectively draining the diesel from the tank too? Is it worth draining the tap now before I drain the main tank?

I'll check it and replace it if needed. Don't want this to happen again if possible.

Yes it's is a flush fit fuel cap type, although I can't see how a significant amount of water could enter. I'm thinking that condensation is a likely culprit. In winter I keep the boat pretty warm and in the engine bay I get significant condensation on the outside of the skin tank which collects a good amount of water in the bilge that I need to pump out. If the same is happening on the inside of the fuel tank then that would be a good amount of water. I intend to keep the tank full over this winter, but any other suggestions if this doesn't sound right would be helpful. Thanks. I think I have found a few 25l containers so will get this done asap. My thinking is that once I have new fuel in the tank, to run the engine to clear the bad fuel through and then replace the fuel filter and drain the water trap. Does this sound a reasonable approach?

Thanks. I will Syphon all the fuel out. Is it okay to just let the fuel.settle and then Syphon the diesel off the top and put that back, or is it going to be better to just dispose of everything and replace with fresh? Is this likely to have done any lasting damage to.the engine?

Doesn't sound good! Okay, my water trap is below my tank, so I'm gonna bleed that and see what comes out.. I syphoned it out from the tank by putting a hose in from the top. I got the hose down as far as I could.. The tank is down to about 50 litres because I didn't want to fill up before fixing this issue..

An update to this topic/issue.. Not been crusing very much after I got off the Thames as well as holidays etc. However, I have now managed to Syphon off some fuel into a glass bottle to see how it looks (photo attached). I will leave it for a week or two and compare. Not sure what I am looking at, so opinions if this looks normal would be appreciated. I still need to locate an engineer to help do a service on the fuel line/filter etc. Chertsey meads marina sounded perfect after I spoke to them, but I was unable to stop as I went past at a time when they were free, so that job still needs doing. Considering learning how to prime it and do the job myself.

Wow that is sooo helpful. Thank you. I think I will find an engineer in London when I am off the river and watch/learn as he does it. No significant increase in the exhaust smoke when it happens.

Thank you. This certainly needs to be checked now then as many have suggested already. My faulty thinking and understanding has (incorrectly) asssumed that due to the correlation with temperature and how hard I'm running it that fuel was a low probability, but those that know better than me keep suggesting fuel so I wil need to get this checked next. Thank you. I will do the fuel inspections. Not done these before so will need to work out where they all are and how to do it. Will be simple after I have done it once. The fuel filter is probably due a change regardless. I'll check the rev counter connections. I have a separate ammeter measuring the alternator charging which looks to be charging correctly. I checked the alternator belt when I changed oil last week and looked to be fine.

So I measured the temperature with an infrared monitor again today and the water going into the skin tank is showing 60 degrees (which matches the temperature gauge) and out of the skin tank is 30 degrees. The revs monitor doesn't seem to be reliable (I think it st is sometimes) but when the problem occures the revs drop. Where is the water pump? Will that be on the back next to the alternator (assuming the belt that does the alternator also does the water pump? I can get a picture of that later if that is correct. Untried something else yesterday/today which was to run the engine a little less hard and it made a difference in that the problem didn't occur until 2.5 hours of cruising instead of just over an hour when running it hard. The problem still occured though although it was less drastic. I still had a reasonable amount of power but still significantly less than when I first get going with a cold engine. Consistently the problem seems to occur when the gearbox measures above 65 degrees. It seems repeatable for the problem to occur with how hard I run it/length of run time which indicates to me that it is a temperature issue ?? Any thoughts on this? Could fuel bug still be the culprit if it is consistent with time/how hard I run it? The large circular plate behind the gearbox (not sure what this is if you can advise) measures at just over 60 degrees which seems to match the water temperature so guessing this is also normal ?

I don't know the history of the engine unfortunately. The previous owner seemed to know what he was doing and seemed to have taken care of it. It smokes a little when I first start it, but mostly runs fairly clean.

The fuel being the issue is starting to look more likely... it just seems so consistent with temperatures... I will need to get some siphoned off to test it. I'll check the bottom skin tank pipe just in case the temperature gauge is broken. Thank you. Engine seems to start fine after a short 5 min stop. One further observation from today's issues. When the issue starts I can hear the engine change so know when it happens. However I don't lose power straight away (a little, but not much). But when I then try and stop .. at that point I have very little forward or reverse power. (I get more from reverse than forward but both are significantly affected. A 30 minute rest and all is back to normal again.

Thanks for explaining that makes more sense now. If the pipes are too small, I'm assuming that the temperature of the gearbox would increase higher than good operating temperature and then cause issues. The 65 degrees seems to be within normal range, unless I am measuring it incorrectly??

Another angle. Later today, I will try running the engine at a slower speed to see the problem still occurs when not being run as hard. Not sure I understand what you mean by number 2.

When I open the boards to measure the temperature it feels pretty cool down there, so i would say that the air getting into the cooler is okay. Photo attached of the water connection. It seems to be connected to the lower skin tank connection (is that the feed or return?) Still need to siphon off some fuel to check this.

Yes I called PRM Newage and left a voicemail, not had a call back yet. If this is not too hot for the gearbox, perhaps I'm measuring it wrong. Infrared sensor on the top of the gearbox from about a meter away. So still could be a fuel issue? It seems linked to the temperature.. my simple brain would have assumed that if it was the fuel it would show itself earlier or at random intervals. The problem is consistently as the engine/gearbox gets hotter.

Tony Brooks identified it as a PRM hydraulic gearbox from the photo posted previously. The engine temperature gauge is showing in the middle of the dial around 80, but doesn't seem to increase too much after its up to temperature. The engine has an air cleaner rather than a typical air filter. Not figured out how this works yet, but there is a small reservoir of oil inside which seems to be at the correct level. (Will try to add a photo). Photo added. Air cooler is bottom right.

Hi Tony, I'm just about to pass Maidenhead later today, we were stuck in Henley behind the lock closure this weekend so not been moving much to be able to repeat the problem. The fuel being the issue I haven't dismissed, I just wanted to address the easier (for me) possibility first. Hi Brian, when I say I dismissed it, I still cleared the prop fully however the wire was small enough that in my experience this would not of caused the issue, and indeed when the problem occured again (with the prop now clear) it seems now unlikely to be the cause. However, it is still possible that something is jammed that I didn't find. So, now I have moved a couple of hours this morning, the problem has showed itself again and I can report that the prop moves freely by hand, however the temperatures look to be high. The gearbox temperature when the problem occurs is up to 65 degrees. Thrust plate is 43, bearing is 38 and gland is 32. So it looks like the gearbox is overheating? And the heat is spreading down the shaft. Does this sound right? Is 65 degrees too hot? When it happened, I let it cool for 20 mins when going through a lock and the temperature dropped to 55. All seemed to be working fine again, but the problem occured again when the gearbox temp reached 65 again. Does this narrow down the issue to the gearbox or could it still be one of the other options discussed? If it is the gearbox, what could be causing it to overheat?

I have a Syphon pump, can I pull some fuel directly out from the bottom of the tank?

My plan is to check a few easy things next time it happens.. the drive shaft still rotates by hand, and check the temperature of the parts when it shows itself.. If this doesn't narrow it down I'll look into the fuel which is a bit harder for me as I've not done that before. Appreciate your input 🙂

Not been very far in last few days so not had the issue again yet. I did take some temperature readings after running the engine for 30 minutes which are below and look kinda normal, so whatever the problem is it seems to start all of a sudden after an hour or two. Temperature readings: Gearbox 43 Thrust plate 32 Bearing 29 Gland 25

Yuck ... Where did tomorrows forecast come from !! Just above reading ATM.