Volvo Penta MD1

[Chrisgus]

Hi Could anyone shed any light on our problem? we have an MD1 that although is 40 yrs old is still running perfectly, however when we start the engine from cold [applying the cold start facility] we get a large amount of soot emitted from the exhaust until the engine revs increase and the cold start is disengaged, as soon as this happens it runs clear and the engine runs cleanly and perfectly all day, with warm starts in between. This soot is emitted with the cooling water and forms a black film on the water. We have recently had the rings replaced and compression is excellant, we have swapped over the injector to our spare and it is still the same. We use standard road diesel, and we are not burning oil. This problem appeared before we replaced the piston rings and we thought by replacing them it would cure the problem. Any suggestions apart from the obvious such as use it as a mooring weight or scrapping, would be appreciated.

Many thanks C

 

[scottie]

the cold start allows extra fuel which is nor being burnt initially thus causing black smoke and soot until the engine catches up with the fuel supply
try sitting behind a lorry starting from traffic lights

 

[Chrisgus]

Thanks for your reply Scottie, this problem only started last year, up till then this didnt happen.
Regards
C

 

[mattnj]

post it on boatdiesel.com it is full of real experts there, i can post it for you if you want as i have a paid subscription....

 

[Chrisgus]

That would be good thanks very much.
C

 

[mattnj]

http://boatdiesel.com/Forums/index.cfm?CFApp=6&Forum_ID=82&Thread_ID=40211

 

[scottie]

cold start button may be sticking down

 

[mattnj]

has been updated

http://boatdiesel.com/Forums/index.cfm?CFApp=6&Forum_ID=82&Thread_ID=40211

 

[Bilgediver]

Hi Could anyone shed any light on our problem? we have an MD1 that although is 40 yrs old is still running perfectly, however when we start the engine from cold [applying the cold start facility] we get a large amount of soot emitted from the exhaust until the engine revs increase and the cold start is disengaged, as soon as this happens it runs clear and the engine runs cleanly and perfectly all day, with warm starts in between. This soot is emitted with the cooling water and forms a black film on the water. We have recently had the rings replaced and compression is excellant, we have swapped over the injector to our spare and it is still the same. We use standard road diesel, and we are not burning oil. This problem appeared before we replaced the piston rings and we thought by replacing them it would cure the problem. Any suggestions apart from the obvious such as use it as a mooring weight or scrapping, would be appreciated.

Many thanks C

The cold start allows the rack to move to a higher fuel position to improve the starting however it is still restricted in its maximum movement by an adjuster screw which on many Md 1 etc was just inside an odd shaped cover on the back of the engine just towards the exhaust side from the cold start button.

It is remotely possible this has either been tampered with or the locknut become loose. Adjusting this carefully could stop this. screw in is for less and out for more. If you screw in too far you will restrict the speed at which the engine accelerates. Keep track of what adjustments you make so you can return it to its original position if this is not the answer.

 

[Chrisgus]

Volvo MD1 sooty deposits

Many thanks will give this a look when im down there again.

Regards
Chris

 

[Jim Bell]

If its any consolation, my 50 yo MD1 does exactly the same (& has been doing so for about the last 200 hrs since rebuild)
Doesn't seem to do any harm. Doesn';t do it when we're sailing!
Jim Bell

 

[Chrisgus]

MD1 sooty start up

Thanks for your reply, like yours this happened over a short period of time and is a bit embarrasing when starting close to shiny gin palaces. Ours runs perfectly when warm.
Regards
Chris

 

[erich4898]

I find your thread very interesting, although done a while ago. I have an MD1 in a boat I aquired about 18 months ago, it had been sat for many years. I changed the oil, cleaned and reset the injector and managed to start the engine with a flow of fresh water from a hose pipe. (boat was on my drive).
I have run the engine for several hours, each time starting perfectly and running sweet.
After a great deal of work to the boat I launched it and took it out on sea trials. This is where the problems started to occure. on "just ahead" within the river estury she ran ok but as the power increased she started to give out black smoke and soot on the water, plus the oil presure started to decrease. I linped back to the mooring.
Two thoughts went through my mind, first a "BUG" in the diesel and blockage in the oil feed. I gave the diesel an anti-bug treatment and checked to see if the injector was operating. It was. I have now mixed oil and diesel (50/50) to clean out the oil channels + filter change. it now won't start. It also jams up as if the rings are getting stuck. This week (weather permitting) I am takeing the head off to check the rings and bearings. If I discover damage to the piston is there any one out there that has a spare they don't want??
One last thing, on other MD1's I have had the oil strainer is part of the dip stick housing which you unscrew and clean. This one doesn't have one but does have an external oil filter. Is this all that is needed to clean the oil?? many thanks. I am brand new to this site but find it most fascinating..

 

[Bilgediver]

Seems like either he cold start button is a bit sticky and n0ot releasing as soon as the engine comes under governor control or the fuel limiting screw might be coming loose and slowly unscrewing. This screw is usually accessed from the rear of the engine through an odd shaped hole covered by an odd shaped plated . this might be sealed with wire, Looking at the engine from the propeller it is on the vertical face below and to the right of the cold start button.

If this screw has loosend off you probably are also getting smoke when increasing the revs. The screw is secured by a lock nut,

If you only get smoke on start up and not when speeding up then it is more likely to be a sticky cold start button which is slow to reset.

 

[scottie]

One last thing, on other MD1's I have had the oil strainer is part of the dip stick housing which you unscrew and clean. This one doesn't have one but does have an external oil filter. Is this all that is needed to clean the oil?? many thanks. I am brand new to this site but find it most fascinating..[/QUOTE]

That is because it's a MD1B

 

[erich4898]

One last thing, on other MD1's I have had the oil strainer is part of the dip stick housing which you unscrew and clean. This one doesn't have one but does have an external oil filter. Is this all that is needed to clean the oil?? many thanks. I am brand new to this site but find it most fascinating..

That is because it's a MD1B[/QUOTE]

Cheers Scottie, you are right. I stripped the engine down and found that the bore is well bigger than the MD1 which makes it a 10hp MD1B. Trouble is now I discovered that the shell bearings had disintigrated causing a slight ovality of the con rod. This was also due to the loss in oil pressure. I am now trying to look out for another con rod, so anybody reading this in the UK and have one please let me know. The piston size is just under 3.1/2 inches across the top.