HELP! Hatz 1b40 engine on my Cherry Picker

[Treeman123]

Hi Guys

 

Just wondering if anyone can help please! The Hatz engine on my cherry picker starts great when cold but when its hot it just turns over. I have to let it cool down before I can start it. I have put a new battery and stater motor on it. Anyone had a similar problem?

 

 

[Ratman]

Does it have the oil level cut out circuit/switch? Some times and it only needs to be as much as an egg cup full when the engine gas run and is still warm some of the oil is still clung to the engine internals higher up than sump level and obviously registers as low oil level and hence the no start till its all dribbled back down and topped the sump up. Honda do a similar thing too.

[woody paul]

Have that engine got an auto decompression set up maybe sticking open so no compression. 

[Treeman123]

22 hours ago, Ratman said:

Does it have the oil level cut out circuit/switch? Some times and it only needs to be as much as an egg cup full when the engine gas run and is still warm some of the oil is still clung to the engine internals higher up than sump level and obviously registers as low oil level and hence the no start till its all dribbled back down and topped the sump up. Honda do a similar thing too.

I think it does have oil sensor, I will check that out cheers 

[Treeman123]

20 hours ago, woody paul said:

Have that engine got an auto decompression set up maybe sticking open so no compression. 

Not sure about a auto decompression, I wondered if the valve clearance could be tight and its sticking? 

[openspaceman]

39 minutes ago, Treeman123 said:

I think it does have oil sensor, I will check that out cheers 

I've only worked on the 4 cylinder Hatz, that has a fuel cutoff which is held open by the fan drive belt tension, if the belt goes slack the plunger cuts off the fuel to the injector pumps (One per cylinder IIRC).

[Treeman123]

1 minute ago, openspaceman said:

I've only worked on the 4 cylinder Hatz, that has a fuel cutoff which is held open by the fan drive belt tension, if the belt goes slack the plunger cuts off the fuel to the injector pumps (One per cylinder IIRC).

This engine is just one cylinder jobby, No belts etc

[openspaceman]

11 minutes ago, Treeman123 said:

This engine is just one cylinder jobby, No belts etc

OK I've just looked at the manual and it seems there is a temperature sensor:-

"Stop signal from monitoring elements that are associated with the au-
tomatic switch-off (optional):
▪ No oil pressure.
 Check the oil level.adding oil if nec-
essary,
 
▪ Faulty AC alternator. Contact Hatz Service.
▪ Engine temperature too high.
 Check the cooling air guides for contamination or other im-pairments.
 8.2.8 Clean the cooling air area,"

 

If this is at all similar to the old air cooled lister diesels then it will be dust on the fins. Also after har work never shut the engine down directly, leave it running at part speed so the fan removes residual heat in the head. Once the engine has stopped the head is still conducting heat from the inside but there is no longer any air flow to remove this and maybe the heat sensor has tripped.
 

 

[Treeman123]

18 minutes ago, openspaceman said:

OK I've just looked at the manual and it seems there is a temperature sensor:-

"Stop signal from monitoring elements that are associated with the au-
tomatic switch-off (optional):
▪ No oil pressure.
 Check the oil level.adding oil if nec-
essary,
 
▪ Faulty AC alternator. Contact Hatz Service.
▪ Engine temperature too high.
 Check the cooling air guides for contamination or other im-pairments.
 8.2.8 Clean the cooling air area,"

 

If this is at all similar to the old air cooled lister diesels then it will be dust on the fins. Also after har work never shut the engine down directly, leave it running at part speed so the fan removes residual heat in the head. Once the engine has stopped the head is still conducting heat from the inside but there is no longer any air flow to remove this and maybe the heat sensor has tripped.
 

 

Thank you for that, I will try clean the fins out as I haven't tried that. If the engine is over heating when its running would it not cut its self out? as mine only wont start after it being hot 

[openspaceman]

20 minutes ago, Treeman123 said:

Thank you for that, I will try clean the fins out as I haven't tried that. If the engine is over heating when its running would it not cut its self out? as mine only wont start after it being hot 

Yes it would cut out whilst running if it is blocked fins but see what I wrote above. Once the engine has stopped the  airflow from the fan stops. So any residual heat from the engine continues to be conducted from the combustion area to the outside and fins but there is now no air flow, so the sensor (assuming it has one)  over heats and trips. It then has a hysteresis such that it has to become much cooler before it resets and you can star again. This was what happened on our lister 3cylinder powered Dosko.