Join Date: Sep 2005
Location: New Westminster, BC
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Re: Full throttle needed to start Yanmar 2GM20F
Ran some tests, cranking and playing with the decompression lever with a cold engine does not feel like it changes anything, it only feels like the compression builds up after the engine warms up. This just might be explaining the hard start problem.
You should notice a distinct change in cranking speed between 'compression on' and 'compression off'... you'll also 'see' the engine shaking harder with the compression lever released as the starter tries to drive the engine through the compression phase.
If you're not noticing a difference, that's definitely something to look further into.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)