looking at a small 20' catboat w 03 yanmar IBD in a few days, can anyone give tips on starting ? in particular--whats' the choke position for a cold start ? i'm bringing my jumper pack in case the batteries aren't fully charged. (and YES i need another boat.)
tips on starting an old yanmar 1GM ?
- Thread starter MitchM
- Start date
Diesels do not have chokes.
Make sure there is oil in the crankcase. Turn it on and hit the start button.
Make sure there is oil in the crankcase. Turn it on and hit the start button.
When cold, our 1989 2GM required a half throttle setting and a long (five to ten seconds) crank before it would begin to fire. After warmup it only took a short (one second) crank to fire. As Dave mentioned diesels do not have a manual choke; all automatic by the injector system. Unsure about the 1GM thumper, but Yanmars typically do not have glow plugs, but worth a check. If so, they need a brief (less than 30 seconds) warmup before cranking. Check for s toggle switch near the ignition switch that indicates a glow plug.. Our 4JH has no glow plugs and, whether cold or warm, always starts on the first short (one second) crank to fire.
Make sure the batteries are good, there is good fuel, the cooling water thru hull is open, check for engine oil.
if all is good, give her some throttle, on my 2GM20 I go 1/4 or 1/2, turn on the key and press the starter button.
Don’t crank it too long if she doesn’t start. You could hydro-lock the engine. If she turns over but won’t fire up, try heating the air at the air intake with a hair drier or something.
Fuel, Air, Compression...if she wont start, it has to be one of these.
Greg
if all is good, give her some throttle, on my 2GM20 I go 1/4 or 1/2, turn on the key and press the starter button.
Don’t crank it too long if she doesn’t start. You could hydro-lock the engine. If she turns over but won’t fire up, try heating the air at the air intake with a hair drier or something.
Fuel, Air, Compression...if she wont start, it has to be one of these.
Greg
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,028
I've had excellent success preheating the air as Tally Ho suggests. I keep one on the boat just for cold starting. FYI, my engine is a 1980 and on its last legs and the hair dryer start still works!
Pretty sure 1 GM has a compression release. After verifying that the fuel stop valve is open, and that there is plenty oil, pull the release and spin it a bit ( maybe like 3-4 seconds) to circulate the oil then turn off the compression release while the motor is spinning. She should fire up pretty quickly. Careful with cranking time because if you have to spin it (without it firing) more than about 90 seconds, you could flood the engine with water through the exhaust .
The 1GM diesel engine does not have a carburetor, hence no choke. It utilizes fuel injection. It also does not have a "glow plug" to help starting. As the engine is cranked it builds compression through a small number of successive revolutions. Compressing the air fuel mixture heats it up to the point of detonation. So in essence to be able to start the engine you need good fully charged batteries, a starter in good running condition and for the engine to have adequate compression. Off course a clean delivery of the air /fuel mixture is also necessary. Cold Weather starting is a little harder on the components as the batteries may loose a little power and the cold oil on the engine will add additional drag on turning the engine to build enough compression. Usually slower cranking will be experienced and few more revolution will be needed before it fires. There are a few tricks to help these engines start, Open the throttle 1/2 to 3/4 to allow a larger volume of air/fuel to build up. In hot weather with a worn engine it may be necessary to increase engine compression and that can be done by using a thicker engine oil 15W40 with a thickening additive (in cold weather a thicker oil may hamper cranking speed). In the eventuality of slow cranking your engine comes equipped with a compression release lever where you can get the engine cranking at a continuous higher speed before closing the lever and allowing full engine compression. Good luck.