Yanmar 1gm 10 starting backwords!

[lexi]

There are some previous threads. This isssue only came about this season. Once started runs fine for 8 hrs no problem.
1/ I suspect an air or fuel issue not starting it on the button as should. It is as though I am having to bleed it every time I start from cold. Can this cause it to not catch and then bounce back to start?
2/ it seems as though enough power is there as it can be "force started" with speed on the starter. It may be an idea to boost it with an added battery and jump leads?

Any thoughts appreciated.

 

[Stemar]

It it actually running backwards? I could see a two stroke doing that, but I can't see how a four stroke diesel would manage it.

Does it have a decompressor? If so, could you spin it up with the decompressor open then close it when it's turning fast?

If it's turning on the starter, but too slowly to go normally, it sounds as though it's one or more of
1. Tired/discharged battery.
2. Poor contact somewhere - look for a warm connection on the main starter lead and the earth lead after turning it over for a few seconds
3. Dodgy starter (worn brushes?)

Check the battery voltage at rest and when turning the engine over. It should be >12v at rest; with the starter running, less than about 10v is probably a battery issue, around 12v suggests problem 2 or, much less likely, 3.

Good luck!

 

[MontyMariner]

The subject line doesn't relate to the questions asked.
When I had a 1GM, I used to turn it over with the decompression leaver up to get it going when the engine was cold or the battery was low.

 

[Buck Turgidson]

If it happens often enough it will kill your impeller so best check that whilst doing the trouble shooting or you could be in for more problems!

 

[Tranona]

If it happens often enough it will kill your impeller so best check that whilst doing the trouble shooting or you could be in for more problems!

Why would that be? he is not shutting off the water.

 

[Tranona]

There are some previous threads. This isssue only came about this season. Once started runs fine for 8 hrs no problem.
1/ I suspect an air or fuel issue not starting it on the button as should. It is as though I am having to bleed it every time I start from cold. Can this cause it to not catch and then bounce back to start?
2/ it seems as though enough power is there as it can be "force started" with speed on the starter. It may be an idea to boost it with an added battery and jump leads?

Any thoughts appreciated.

Not unusual with 1GM. Don't think it is fuel/air, although worth bleeding and checking there is good flow at the injector. Common way for air to get in is poor sealing of the fuel filter casing at the back of the engine. Turning over for 10 seconds or so with the decompressor lever up before starting is useful to get oil flowing and help the rings seal. On the electrical side as suggested check all the connections to battery and starter motor, plus the multi connector in the wiring loom. There is also an in line fuse that can have a poor connection, although this is more related to intermittent operation of the starter.

 

[VicS]

Why would that be? he is not shutting off the water.

If the engine runs backwards so will the pump and it will be trying to pump water from the engine to the sea.

 

[dukeofted]

My 1GM10 was easier to start backwards than forwards when cold! Solved it by getting the injector serviced, it was dripping and had a terrible spray pattern. After that was sorted it started on the button every time. The other thing it could be is injector pump timing.

 

[Cariadco]

The answer is simple. use the Heater Plug, every time.
Regards.

 

[dukeofted]

You might struggle to do that on these engines!

 

[snowbird30ds]

Why would that be? he is not shutting off the water.

The vanes will be switching direction which causes far more rapid failure at the vanes bases.

 

[MontyMariner]

The answer is simple. use the Heater Plug, every time.
Regards.

Is there a mod kit to put a heater plug ona 1GM?

 

[Buck Turgidson]

Why would that be? he is not shutting off the water.

As the others have said it will wobble the blades the wrong way each time it happens. There is a warning in the operating manual for exactly this reason about turning the engine by hand.

 

[snowbird30ds]

Is there a mod kit to put a heater plug ona 1GM?

You can put a heater plug into the inlet manifold surely (I have no knowledge of a 1GM) and the rest would just be a wiring job.

 

[lexi]

Thanks for all replies! I am thinking it is starting backwards as it is only starting from cold when you stop the pressure on ignition key spring. As it loses turning momentum and almost comes to a halt, it seems to start and reeks smoke out of engine compartment. Sound rough as. Killing engine and then trying again it will spin up on key and if you keep going 10 seconds, it might fire reluctantly and then it is smoke free and running. Always spin it up with decomp to get oil up initially. The trick of spinning up and dropping decomp, only encourages the rough starting, as it starts at the end of flywheel rotation. It seems to bang against the compression as flywheel nears stop of rotation..........then rough as hell running and smoke.
Get it started and fine all day. I better check oil levels and see if they are raised with fuel dilution.
One thing I have realised now I may have been doing wrong, is I am not giving any throttle on start up. This is my second full season with this engine and all last year it started from neutral in tickover speed. Will try in 3/4 throttle along with the other things. Water impeller was first thing I feared for as I know how easy they get fins broken. I thought of oil pump gear too. The speed it is spinning at on the starter motor should start it I think..........sounds about same as last year.

 

[MontyMariner]

Will try in 3/4 throttle along with the other things

I would suggest that 3/4 throttle is high. 1/3 should be enough.

 

[LiftyK]

I had this happen during a spell when I had an alternator problem and mistakenly used an alternator with an overly heavy load due to incorrect pully size. Could your engine be experiencing unusually high load at start up?

 

[Cariadco]

The reason I recommended using the Heater plug (although I wasn't aware they aren't fitted to the 1GM) is a few years ago, I helped a mate ,service 20 charter boats. Some had single cylinder engines and he instructed me to use the glow plugs as they are notorious for starting backwards. He also instructed me what to do, if one did start backwards.

 

[JVL]

There are some previous threads. This isssue only came about this season. Once started runs fine for 8 hrs no problem.
1/ I suspect an air or fuel issue not starting it on the button as should. It is as though I am having to bleed it every time I start from cold. Can this cause it to not catch and then bounce back to start?
2/ it seems as though enough power is there as it can be "force started" with speed on the starter. It may be an idea to boost it with an added battery and jump leads?

Any thoughts appreciated.

3/4 throttle is the cold start for the gm10 , it’s in the manual

 

[scottie]

Is advice without experience sometimes dangerous?