yanmar b08-3 won't start

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sandbags89

Member
does anybody know what this is....

we were tracing wires to find out why the relay switch stopped working, come across this which was loosely sitting under the footwell. It doesn't look like it plugs into anything.... what might it be for?

IMG_20220616_123943.jpg
IMG_20220616_123952.jpg
IMG_20220616_123959.jpg
 
Mick-the-fitter

Mick-the-fitter

It’s what I do!
Just be careful operating the relay manually, as the timer relay is there for a reason! Although if you unplug the solenoid, on the cable from the machine end you would have earth, ignition 12v, and starter 12v through a timer relay.
 
M

Monkeybusiness

Well-known member
Will it start up with the solenoid removed entirely, so the fuel rack is definitely open?
 
S

sandbags89

Member
Will it start up with the solenoid removed entirely, so the fuel rack is definitely open?
yep tried this. same results.


Just be careful operating the relay manually, as the timer relay is there for a reason! Although if you unplug the solenoid, on the cable from the machine end you would have earth, ignition 12v, and starter 12v through a timer relay.
IMG_20220616_134935.jpg

machine side of the solenoid. so earth and then the other 2 must be as you said. That green wire runs to the electromagnetic relay switch shown below...

IMG_20220616_135023.jpg

in this pic we have the relay switch with the cover off (the one i manually operate for solenoid) and that on the left is a timer apparently, according to diagrams online:


so far im thinking that this timer may be the issue for not sending signal/power to operate the relay switch. can't see any breaks in the cable. I don't get why it suddenly stopped working :confused:
 
Mick-the-fitter

Mick-the-fitter

It’s what I do!
Ok there is a way round this to see if either relay is at fault, pull the plug that goes to the stop solenoid, do you have a volt meter?
 
V8Druid

V8Druid

do it as well as you can,but learn to do it better
V8Druid

V8Druid

do it as well as you can,but learn to do it better
yep tried this. same results.



View attachment 36636
machine side of the solenoid. so earth and then the other 2 must be as you said. That green wire runs to the electromagnetic relay switch shown below...

View attachment 36637
in this pic we have the relay switch with the cover off (the one i manually operate for solenoid) and that on the left is a timer apparently, according to diagrams online:


so far im thinking that this timer may be the issue for not sending signal/power to operate the relay switch. can't see any breaks in the cable. I don't get why it suddenly stopped working :confused:
big red is supply to the one side of the HD relay, green feeds it from there to the solenoid when it is energised ...
red/white is supply to the coil to activate the relay and green yellow will almost certainly be earth .... put a live to the HD relay red/white terminal .. if it actuates it's the red/white supply not functioning ... where is it coming from? ... if it doesn't, try adding an earth to the green/yellow terminal and try again ... if still non functional 99% it's ****ed
 
S

sandbags89

Member
Ok there is a way round this to see if either relay is at fault, pull the plug that goes to the stop solenoid, do you have a volt meter?
yes, i believe i have a multimeter...
IMG_20220521_094859.jpg


looks like a plug with a rubber bung in it ... prob.s for an option not fitted ?
yes i did manage to open the end up. It wasn't just a plastic/rubber end cap as I thought the same as you, seemed to have 2 metal prongs that plugged
into it...
IMG_20220616_211206.jpg


big red is supply to the one side of the HD relay, green feeds it from there to the solenoid when it is energised ...
red/white is supply to the coil to activate the relay and green yellow will almost certainly be earth .... put a live to the HD relay red/white terminal .. if it actuates it's the red/white supply not functioning ... where is it coming from? ... if it doesn't, try adding an earth to the green/yellow terminal and try again ... if still non functional 99% it's ****ed
had to read this a couple times :LOL: yes that sounds right. it seems that red/white wire is not doing its job in activating it. I will try putting a live feed to it as suggested. in the mean time here are some images of where some of the wires lead to...


starting with the HD relay as you called it (what does the HD stand for?)
IMG_20220616_210644.jpg

following the red...which is spliced and taped to 3 other red wires....
IMG_20220616_210729.jpg

2 lead over to near the battery...1 goes to this other type of relay thing
IMG_20220616_210821.jpg

and the other goes to this fuse
IMG_20220616_210834.jpg

the 3rd red dissapears into the footwell and im guessing goes up to igntion or something
IMG_20220616_210900.jpg
 
S

sandbags89

Member
now following wires from the other 'timer' relay
the back 2 go to the hd relay as shown in previous images. the black is just earthed to the body...
IMG_20220616_211008.jpg

the yellow w/red strip...leads to here where it is crimped with 3 otherswhite white
IMG_20220616_211016.jpg

white and black leads to mystery device


IMG_20220616_211040.jpg


the yellow and black on the rightside of the crimp goes to the solenoid connection...
IMG_20220616_211033.jpg


the yellow and black on the left side of crimp goes back up to this connection for the fuses
IMG_20220616_213453.jpg



i hope those images made it clear enough
 
V8Druid

V8Druid

do it as well as you can,but learn to do it better
the 3rd red dissapears into the footwell and im guessing goes up to igntion or something
View attachment 36653
probably the live feed to all those wires from the ignition switch .. one to the fuse is probably supply to that fuse and then on to whatever it feeds ..third to the "other type of relays thing" is almost certainly the switched supply from the ign. sw. to that unit, looking at the size of it.

is there any continuity across the two pins of that plug you pulled out ... try it both ways - if it's a diode will only be continuity one way .. if both could just be a link -- or possibly a fusible link, but doesn't appear to have any value markings on it

HD = heavy duty ;) as opposed to your average 30A, 5 pin std little relays

where is the red/white wire feeding from ?
 
S

sandbags89

Member
probably the live feed to all those wires from the ignition switch .. one to the fuse is probably supply to that fuse and then on to whatever it feeds ..third to the "other type of relays thing" is almost certainly the switched supply from the ign. sw. to that unit, looking at the size of it.

is there any continuity across the two pins of that plug you pulled out ... try it both ways - if it's a diode will only be continuity one way .. if both could just be a link -- or possibly a fusible link, but doesn't appear to have any value markings on it

HD = heavy duty ;) as opposed to your average 30A, 5 pin std little relays

where is the red/white wire feeding from ?
which red white do you mean?
 
Mick-the-fitter

Mick-the-fitter

It’s what I do!
1- with the solenoid lead off the solenoid socket, with volt meter switch to volts, put the red lead to the battery pos, with the black find the earth on the lead plug to the solenoid.
2- now turn on the ignition,,keep your meter on volt’s put the black lead on your battery earth, with the red lead you should find the solenoid positive ign supply.
3- the remaining wire to the plug is the timed throw in current to the solenoid when starting.
Make sure you never get a continuous 12v to the throw in side of the solenoid as it will melt internally, make a note of where your lead plug wiring is,
4-with the solenoid socket fix an earth wire to the terminal (could be white or black, depending on the manufacturer of the solenoid) the with a 12v pos wire touch one of the two remaining terminals, if there’s. Loud click and the pin flys in, this is the throwing current terminal (let go) the remaining terminal is the holding current, touch a live on this one, with the earth in place you can push the pin in and it will stay in.
 
S

sandbags89

Member
right, a long over due update. Apologies to those who have been following the thread.

So good news, managed to get the solenoid working. Ending replacing both these 2 relays, it was the left one that was the culprit. The other one needed changing anyway where i pryed open sealed unit.
IMG_20220616_135023.jpg

So the solenoid was operating as it should again, so we were just back to the issue of non-start, and since we were convinced on lack of compression i was working up the courage to open her up. However before we got to that, our mechanic gave us the number of someone who works on lorries and other diesel engines so we gave him a call and got him down to have a look.
Turns out he works with these engines and similar lot for generators and other machinery. He turned it over, done the usual checks, had a listen, sprayed some easy start and fairly quickly came to the conclusion that it was a piston ring (or related to that). Was quite a relief, he seemed to know more what he was talking about than the other engineers that came down, and seemed to come to the same conclusion that we did (us in the forum).

Few days later he came down, ripped out the engine...
IMG_20220707_145015.jpg
IMG_20220707_152932.jpg
IMG_20220707_153001.jpg
IMG_20220707_152953.jpg

gave the chassis a good clean out, as you can see was full of dirt, oil and muck. Don't have the after photo unfortunately.

He took it away, opened it up further and confirmed it was the piston rings, there was a crack. Gutted i forgot to take photos of it to show, think i was just relieved that we had diagnosed the problem. Had to wait a week or so for the replacements piston kit to arrive. He swapped out the parts then brought the engine back to refit...

and there she goes, finally back to work.
A huge thank you to all of your input, seems like one of the few remaining forums that still offer genuine advice and support.
Much appreciated, and sorry again for the delayed updates.
 
diggerjones

diggerjones

Well-known member
right, a long over due update. Apologies to those who have been following the thread.

So good news, managed to get the solenoid working. Ending replacing both these 2 relays, it was the left one that was the culprit. The other one needed changing anyway where i pryed open sealed unit.
View attachment 38783
So the solenoid was operating as it should again, so we were just back to the issue of non-start, and since we were convinced on lack of compression i was working up the courage to open her up. However before we got to that, our mechanic gave us the number of someone who works on lorries and other diesel engines so we gave him a call and got him down to have a look.
Turns out he works with these engines and similar lot for generators and other machinery. He turned it over, done the usual checks, had a listen, sprayed some easy start and fairly quickly came to the conclusion that it was a piston ring (or related to that). Was quite a relief, he seemed to know more what he was talking about than the other engineers that came down, and seemed to come to the same conclusion that we did (us in the forum).

Few days later he came down, ripped out the engine...
View attachment 38784View attachment 38785View attachment 38786View attachment 38787
gave the chassis a good clean out, as you can see was full of dirt, oil and muck. Don't have the after photo unfortunately.

He took it away, opened it up further and confirmed it was the piston rings, there was a crack. Gutted i forgot to take photos of it to show, think i was just relieved that we had diagnosed the problem. Had to wait a week or so for the replacements piston kit to arrive. He swapped out the parts then brought the engine back to refit...

and there she goes, finally back to work.
A huge thank you to all of your input, seems like one of the few remaining forums that still offer genuine advice and support.
Much appreciated, and sorry again for the delayed updates.
I like the sound effects 😂
 
D

Danoc

New member
Only just read all these posts last night.
My Takeuchi tb007 with same engine as this has not been running right.
Read through all these post which were very useful.
But someone said about the hammer control pedal being stuck on.
Went to my machine this morning and played about with pedal and it sorted out my machine. I would have never figured this out.
Thanks thanks for this
 
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