Yanmar yse 8 diesel engine

[wilky47]

I have a yanmar yse 8 diesel engine which has decided to pour out lots of black smoke and has lost power I have been told it may be that the piston rings have gone any body had experience of this and is it an easy job to do yourself Thanks

 

[dickh]

Before stripping the engine, check that the exhaust water injection elbow is not carboned up internally. A common problem with a lot of engines. But make sure you remove the elbow completely to examine it on the bench. Mine, on a Perkins Perama, had the bore reduced to about ½" diameter when it should have been 1½" diameter! Like a new engine when replaced - I did try chipping the 'coke' out but my chisel went straight through the casting!

 

[l'escargot]

If you need a workshop manual, PM me and I will email it to you. Haven't done that job myself but they are reasonably easy engines to work on, I have stripped one down for parts.

 

[wilky47]

Hi
Thanks for the reply could you e mail me the workshop manual my e mail address is clive.wilkinson8@btinternet.com thanks

 

[pvb]

Or download it...

Or you can download the YSE8 manual here.

 

[sailorman]

the yse 8 & 12 are prone to water laying in the bore ( always in the same place as horizontal cylinder ).

it might be worth checking the height of the injection bend + anti-vac arrangement when you have fixed the immediate prob

 

[l'escargot]

Clive, I will sort that - may be an idea to edit your e mail address in your post so that spammmers don't collect it, just chnage the @ to at or take out the dot.

 

[earlybird]

As said already, the YSE8 is fairly straightforward to dismantle. A cover plate held by 6(?) setscrews gives access to the big-end bolts, and as I remember, the big end itself passes through the bore, after removal of the head. If you have reasonable space either side of the engine, you could do this in situ. Further strip-down would probably require engine lift-out, but beware, removal of the flywheel from the crankshaft taper is not for the faint hearted! However, before you go to these lengths, are you sure that the rings are at fault? what is compression like? Is there blow-by into the crankcase? Is starting poor? Lots of black smoke could be the fuel system, I suggest checking this out especially the injector, before going further.

 

[sailorman]

if removing the injector you MUST replace the washer / gasket , its a flat material with a hole ( just like a washer infact ) the face of the injector is flat.

 

[wilky47]

Hi
Thanks for the reply . The injectors were done quite recently by the prevoius owner so I dont think it is the injectors . When i removed the oil fill / dipstick smoke came out of here would this be blow by ?
On a diesel engine how do you test the compression know how to do it on a petrol engine .
Thanks

 

[sailorman]

on the yse 8 & 12 there is a crank case breather on the port side this would have an oily discharge if there is "blow-by"

 

[cgaa186]

We had similar problem with an old YSE12 engine and as dickh said
was due to the exhaust elbow being almost completely blocked. Worth looking at that I think before more serious dismantling.

 

[earlybird]

Turning the engine over with the starting handle will give some idea of the compression. If the piston, rings & valves are in reasonable shape, then turning over TDC will be very difficult. If continuous turning is possible by hand, (with the de-compressor shut ), then something is wrong.

 

[davey]

Yanmar Problems

Turning the engine over with the starting handle will give some idea of the compression. If the piston, rings & valves are in reasonable shape, then turning over TDC will be very difficult. If continuous turning is possible by hand, (with the de-compressor shut ), then something is wrong.

I know that this is an old thread but there are other things it can be. Barnacles on the propeller for example! This applies to all makes. If you are ever lucky enough to get to tropical waters the barnacles may grow faster. Good luck!

 

[johnjfrake]

I have just bought a second hand one of these and will be running it up shortly so may find similar issues to yours. I can pop a cdrom of manual and parts list in post if you want them. If you have the time a photo of the mounting arrangements would be appreciated.

regards

john

 

[l'escargot]

This is a 4 year old thread - the original poster hasn't been back to the forum since October 2010...

 

[fishing_billfish]

can you get spare parts for yanmar yse 8 engines like head gaskets engine gaskets and engine parts thanks rob

 

[fishing_billfish]

hi can you still get parts for yanmar yse 8 like head gasket and engine gasket all so engine parts thanks rob

 

[johnjfrake]

hi can you still get parts for yanmar yse 8 like head gasket and engine gasket all so engine parts thanks rob

Ys they are available if you do a web search: French Marine is one source, Pro-Rig Marine another! Also comne up on EBay and boats and otboards from time to time.

Regards

John

 

[fishing_billfish]

thank you john i will have a look thanks a lot rob

Ys they are available if you do a web search: French Marine is one source, Pro-Rig Marine another! Also comne up on EBay and boats and otboards from time to time.

Regards

John