Help...I think my Bukh's just died!!

M

marksaab

Well-Known Member
Joined
18 Sep 2006
Messages
145
Location
London, Mersea
Visit site
Help...I think my Bukh\'s just died!!

After spending the last 8 weekends refitting our Seamaster 23 one last task was to descale the engine. Hose connected etc, warming up slowly then we noticed a change in engine note.

The engine has always had a pronounced diesel knock but now we think its the big end gone! Being a bit sad I recorded the noise, I will call the Bukh boys on Monday and replay it to them!

Anyone had a similar experience, parts are available but crank regrind, bearings, piston etc will come to over 700 notes!!! Could re power, any suggestions welcome.

Thanks Mark
 
Re: Help...I think my Bukh\'s just died!!

Now this might sound silly but....

If you have a faulty injector it can cause one hell of knock, which could be mistaken for a big or top end...just a thought before you spend a ton of money on it..
 
Re: Help...I think my Bukh\'s just died!!

Contrary to many people's opinion I don't think it makes economical sense to rebuild an old Bukh.I assume yours is old.Parts are hideously expensive and despite being a robust engine so are the more modern ones on the market today.An old raw water cooled engine is bound to have deposits clogging the waterways and that is tough to get rid of.One problem with these engines is the bearing area for the crankshaft seals.It can get pitted and then it'll always leak.If the engine needs a crank regrind that means taking it apart.You're bound to find other problems and the cost will soar.In the end you'll pay more than it's worth even if you do most of the work yourself.I speak from experience.
Unless your problem is a small one(doesn't seem to be) I think a new engine is the sensible way to go.
 
Re: Help...I think my Bukh\'s just died!!

Good advice.

I had an old very leaky Bukh 10, spent a grand on it to try to stop it leaking.

Wasted money.

Then spent £2500 or so on a brand new kubuto engine. Freshwater cooled, alternator, started first time every time, clean, etc.

Best £2500 ever spent.(year 2000)

Then I sold the boat the following year, and guess what, now have an old Bukh 20, which touch wood works just fine!!!!!


Bit the bullet....

Mj
 
Re: Help...I think my Bukh\'s just died!!

Thanks for all the advice so far! looked through the manual and picked up on most of the possible causes not done any serious fault finding yet.

Def agree about not spending too much on it, if the bearings are ok then I just want it to last this season then we are selling her anyway, already rebuilt the water pump and drive, which is why I suspect water in the oil may be the problem.

I have looked at a couple of Yanmar 10's, may go for this if it prices out to under 1K.
 
Re: Help...I think my Bukh\'s just died!!

I had a Seamaster 23 once called Freebird. I forget exactly how long I sold her. Where /when did you get her? I can't remember the sail number unfortunately. She was a mark 2 model with bilge keels. I'm trying to recall anything identifying about her.
 
Re: Help...I think my Bukh\'s just died!!

Hi
I bought her last June, she is at West Mersea now, when we were cleaning her stern we found an old name "For Leather"!!

Cant remember her sail number. Her SSR is 127547, bilge keels, all white, plastic rubbing strip.

It would be nice to chat if you did once own her.

She's a great boat, my first, having spent so much effort getting her ready we are a bit down about the possible engine woes!!

Mark
 
Re: Help...I think my Bukh\'s just died!!

Having spent most of today looking at options we have one possible solution, she has an outboard mounting bracket, we could use a 15/20 HP outboard, it would also give enough output to keep a battery topped up, I can have a bracket made to fix the fuel tank on the stern replacing the boarding ladder.

Anyone have any thoughts on the above?

Thanks Mark
 
Re: Help...I think my Bukh\'s just died!!

On the positive side you definitely won't need 15 to 20 hp. Outboard horsepower is measured at the prop not at the gearbox so a 10hp outboard has the same hp as a 8.5hp inboard. A 9.9hp high thrust will be more powerful than your present inboard. It won't give you any prop wash over the rudder though, so steering at low speeds will be more challenging.

On the negative side, the weight distribution will be a problem. Your boat wasn't designed to have 35kg hanging off the stern. It may not be a problem if she is a heavy boat anyway. If you take the inboard out, the weight distribution will be even more of an issue though.

Can you check if they were built with an inboard/outboard option? If so, the designer already factored the option in.

We have an outboard on our 27 footer and prefer it to a diesel inboard because it's cheap and easy to service and very light and reliable. A brand new replacement is £1400. And it doesn't leak water or oil into the bilges!

Good luck sorting the problem.
 
Re: Help...I think my Bukh\'s just died!!

I think it highly unlikely to be a bearing failure the way you describe it. Bukhs use plain shell bearings throughout, and these only 'go' after extended wear over a period of time. A sudden knocking will almost certainly have another cause - the most likely being an injector fault, or some problem with the valve gear. These engines always are very 'clattery' so when an injector starts knocking it can sound as though something dire has happened.

With the engine cold, watch the oil warning light when you start. If it goes out almost immediately (within < 2 -3 seconds from the engine firing), then the bearings are good. If it stays on for 7 or 8 seconds, or comes on on tickover, then that would indicate low oil pressure and a possible bearing problem. But there could be other causes of low pressure too, like a stuck relief valve, so its not necesarily conclusive.
 
Re: Help...I think my Bukh\'s just died!!

Hi
Really welcome the info thanks!

Dont think she was really intended for outboard power, we were thinking of taking the Bukh out, I think we will (if its U/S) but we can always use ballast if required.

The engines been knocking for a while, the oil pressure light has never worked, we thought it was just the dodgy electrics but its still not working even after the rewire, i will test the switch this week. The worrying thing is that the knocking continues even when the fuel is cut off when stopping.

Fingers crossed for good news from Bukh!
 
Re: Help...I think my Bukh\'s just died!!

The oil light switch is low down on the block just forward of the oil filter, and even from Bukh only costs a few pounds!

You could try rotating the flywheel with the decompressors on, to see if it turns smoothly. You may feel a resistance at the point where it knocks. It would only confirm the problem is not the injectors. But if there is no resistance it doesnt mean it is not mechanical though.

Is the knock a heavy thumping sound, or a sharp metallic click like a hammer on metal? If it sounds metallic then more likely to be a piston or valve gear fault than the heavy thumping of a crankshaft problem.
 
Re: Help...I think my Bukh\'s just died!!

Quick update, Bukh think the problem is that we used a hose pipe to feed the water pump the pressure was way too high and its probably gone past the seals and filled the sump!

Oil was going to be changed anyway so hopefully we will be ok after that.

Fingers and everything else crossed!!

PS The sound is more metallic but I played recording I made to Bukh and they think is ok
 
You must log in or register to reply here.

Share this page

Top