Yanmar 1GM10 starts but can take up to 5 mins to 'pick up'

[colinH1954]

Hi, I wonder if anyone can help me with my 1GM10 starting problem:
It fires fairly quickly but can take up to 5-6 minutes to 'pick up' & run. Once running, it's fine & will then start & run easily when still warm.
Engine was rebuilt approx. 140 hrs. ago & this problem has gradually worsened. Am told it sounds like a low compression problem. (Fitted exhaust anti syphon valve when rebuilt). Any advice would be welcome. Thanks.

 

[davidbfox]

Could it be a sticky governor?

 

[Bilgediver]

Hi, I wonder if anyone can help me with my 1GM10 starting problem:
It fires fairly quickly but can take up to 5-6 minutes to 'pick up' & run. Once running, it's fine & will then start & run easily when still warm.
Engine was rebuilt approx. 140 hrs. ago & this problem has gradually worsened. Am told it sounds like a low compression problem. (Fitted exhaust anti syphon valve when rebuilt). Any advice would be welcome. Thanks.

Is it possible it is high alternator load. These engines can be reluctant to rev after starting sometimes if there is excessive demand on the alternator.

 

[Storyline]

Sounds like it is knackered - best take it out, cut a hole in the bottom and stick an outboard in.

(Sorry - could not resist - hope you get your engine sorted soon )

 

[sailorman]

oil grade, might be too thick ??

 

[Mel]

I do not think it would start easily if the compression is down
Diesel needs a good compression to fire especially when cold
Low compression should show with smoke due to poor combustion

 

[rotrax]

I would take the fan belt off to eliminate high alternator loading. If it makes no difference at least that is eliminated.
Too heavy an oil is possible, low compression is unlikely if it starts readily.
Good Luck.

 

[JumbleDuck]

Mine had a bit of that until I changed the head. Everything possible was wrong with it, but I think the germane issue was probably a bent exhaust valve stem, binding slightly until everything heated up. Compression test, cold and hot, I'd suggest.

 

[GaryE]

Taking the belt of is a good place to start.
If I remember rightly these engines have an oil temperature switch in circiut which prevents the alternator loading up until the oil has reached a certain temperature.
Does the engine sound as if it's working hard as soon as it starts? Black smoke from exhaust during this time? Not sure what you mean when you say, "it fires fairly quickly but can take up to 5-6 minutes to 'pick up' & run". Is the starter still cranking the engine for the 5-6 mins?