Megafugle

Ok. Im back, but not in a good way...! Raw water system definitely working as it should. Water flowing very well from the exhaust. Coolant levels in the heat exchange were appropriate. Took her out for a couple of hours. All went well. Left her for the night, checked coolant level in the heat exchange in the morning, and its empty again. Something is definitely amiss. Earlier on in the thread it was mentioned that there may be a puncture in the heat exchange core/manifold which might cause a leak. Considering I can all but confirm the raw water system (and ive checked the sea cock, water pump, impeller, belts and oil levels) is working as intended, would this now be something I need to consider? Is there any way to test for this? Thanks again.

I cant claim credit for this, but I managed to get a friend of mine to remove the water pump and the brass plate today. It was attached to some kind of belt/pulley thing so well above my level of expertise (I also do not have many useful tools). Ive attached pictures of the inside below. To me, the impeller looks in pretty decent condition? There was a nice tight seal around the brass plate. The good news is, after we fiddled and put everything back together, we are now seeing a good flow of water from the exhaust. I am still going to monitor the coolant level in the heat exchange next time we take her out for a spin, but at the moment, I am hoping we are all ok....... (If im wrong about the impeller looking ok, please tell me by the way!) If the coolant levels in the heat exchange drop, I might be back..... Thanks again for all the assistance.

Thanks again everyone for your replies. Im going to attempt to take the water pump off this weekend. Will keep you posted!

Hi both, Thanks again for your helpful comments. I think this might be starting to get a little above my level of expertise/ability. Checking for leaks and replacing an impeller, will this require a trip to a marina for a proper job, or is it something a marine engineer can do in situ? I appreciate this is a bit of an open ended question but having just purchased the boat and having had it transported here, im trying to reduce any unnecessary expense. Id rather get it properly done so I dont have to worry about in the future. Thanks

Apologies, to clarify. The water in the heat exchange is low/empty once we have been out for a drive, come back, waited for the engine to cool down and then checked the coolant levels. I dont open it when we are underway. Ive also now noticed that the raw water exhaust is not spouting out any water. It was yesterday I promise! As such, most people have suggested I check the impeller. For my understanding, I presume the brass plate in the pictures below is the impeller? Ive looked at a few videos and they seem to suggest I simply remove the brass plating, pull out the fan part and then replace. This looks easy enough in the videos I have seen yet my impeller seems to be in a position where I cant possibly unscrew the screws due to proximity of the black metal plate. Im not sure how to proceed.

Hi both, Thanks for your replies. Can confirm there is water coming out of the exhaust from the raw water. Its been checked for any blockages and the weed catcher has been emptied and cleared. Interestingly, the water in the heat exchange only drops a little when the boat is left overnight, but a lot when she is moving. Presume this leads further weight to the argument the coolant is leaking into the raw water system? The raw water impeller has been mentioned a couple of times so I will check this next and if necessary replace. Is this the sort of thing I need to buy? https://www.asap-supplies.com/products/jabsco-flexible-neoprene-pump-impeller-spline-drive-12-blades-jab-1210-0001-p I can youtube a video of how to replace it, but for my guidance, would this be considered a fairly simple job or am I better off calling someone in to do it for me? I would estimate my level of expertise as about a 3/10... Thanks PS Thanks again for the observation regards fuel filter mounting. It looks like my list of things to do is growing!

Hi, Was hoping someone might be able to assist me with an issue I am having. Ive recently bought a new cruiser and inherited a 1.8 BMC marine diesel engine. I am having an issue with overheating and I think this is related to the heat exchanger. The issue I am having is that the heat exchanger requires a top up of nearly 3 litres for every hour or so of being used. This clearly seems excessive to me but I can not see the problem. The engine starts fine first time but I am assuming it has a leak somewhere? There also appears to be an oily substance in the heat exchange itself which would seem unusual as I am topping it up with water only at the moment. Was hoping someone might be able to assist me with diagnosing the issue, I have a rudimentary knowledge of this engine but please treat me as a layman! Thanks

Thanks for all the suggestions, will try this out at the weekend and see how it goes.

Hi Tony, Thanks for your email. We had the idle speed tuned by RCR and when sitting in neutral at rest, the engine ticks over fine. It only seems to encounter difficulty when we have been underway for a short while and then come to a stop. Could this still be linked to the mixture? Thanks,

Hi, Am hoping someone could help me/point me in the right direction. We have a Honda 15A BAAS 1203567 petrol outboard engine attached to a Dawncraft 25 boat which we use on the Grand Union canal. The engine has been recently serviced and passed with no problems. Carburettors are fine, thermostat is fine, oil levels are fine and under test conditions everything checked out ok. However, when we use the boat, when coming into land, or to turn around, we are having issues with the engine stalling. This seems to happen when we are moving from forward throttle into neutral, particularly when doing this at low speeds. The engine always starts up again immediately, and moving forward or backward when cruising at a constant speed is fine. Does anyone have any idea why when we move from forward to neutral we are experiencing this stalling? We have had the engine turned up so that it idles at high revs but this does not seem to have helped. Weve replaced the fuel with brand new fuel and this also doesn’t seem to have helped. Any ideas most welcome. My favourite toy is currently sat outside not moving and I miss it! Thanks.