How long til your 3GM starts?

Feb 16, 2021
389
Hunter Legend 35.5 Bellingham
I’m curious, how long does everyone have to crank til their cold Yanmar 3GM30F starts?

I’ve heard everything from instantly to three solid 10 second cranks, plus using compression levers and heat in the air intake, etc.

I’d just like to know what the norm is.
 
Apr 25, 2024
378
Fuji 32 Bellingham
I can't speak to that engine, but with my Universal M-35B, I preheat for 5 seconds and crank about 3-5 seconds. If it doesn't fire right up, I continue to hold the preheat button a few more seconds, then try again. She always fires up within a second or two - no matter how cold or how long it's sat. Because of this, I wouldn't crank for 10 seconds at a time, on the assumption that, if it doesn't fire up in the first 5 seconds, something else is wrong.
 
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Likes: JoeWhite
Jun 14, 2010
2,290
Robertson & Caine 2017 Leopard 40 CT
If it doesn’t start within about 5 seconds something is wrong. 2 or 3 short cranks should be enough. If not stop and trouble shoot. Repeated or extended cranking can pull water into the cylinders and cause hydro lock, and if that happens it’s game over for your engine.
 
Last edited:
Nov 6, 2006
10,055
Hunter 34 Mandeville Louisiana
3gmf ... a couple of seconds. But it is never really cold here. Even when the outside air temp is pretty cold, the engine compartment is close to water temp, not below around 50F.
 

degas

.
Aug 14, 2023
26
Tanzer 29 Lake Ontario
Is that with the Yanmar recommended cold start procedure or not ?

For a 2GM20F with cold start procedure, about 3 - 5 seconds.
The same for my 2GM20. The 2GM20 doesn't even have glow plugs. The manual's cold start procedure is pretty simple, and it works every time.
 

wpatch

.
Apr 8, 2022
19
Hunter Hunter 36 Baltimore
When temp above 60 and she has been run within 2 weeks 2-3 cranks and once she catches some throttle. If cold and not run for a bit I usually give it too much fuel and it takes about 4 tries. I am impatient. I have been told I should let it crank a little longer and not give it throttle early.