I've tried every imaginable throttle position, and nothing seems to make a difference. The manual says to use full throttle, and I've read that the full throttle position actually has an injection pump retard to it. Full throttle does seem to work better when cold, but after having started once, any throttle position seems to work fine, especially idle.
Have not checked compression or valves yet, hoping that someone can tell me what the magic problem is. I don't have an adapter to fit the injectors for compression check. I can't imagine that valves are too tight, as they would become tighter with a warm engine and then even less compression, but could check. Still hoping that someone has cracked this egg before. Richard Arper rtar...@wavecable.com -----Original Message----- From: Dave S [mailto:syerd...@gmail.com] Sent: Friday, June 6, 2025 6:50 PM To: Stus-List Cc: Stus-List; Richard Arper Subject: Re: Stus-List Yanmar 3GM30F starting Do you give it a bit of throttle when you cold start? (I know it’s not actually a throttle) Have you adjusted the valves? Have you checked the compression? My 2gm20F was bulletproof but it preferred if I cracked the fuel open a bit when cold. It also was noticeably …. Crisper… when the valves were adjusted correctly and after a good long high rpm run. Dave Sent from my iPhone > On Jun 6, 2025, at 8:59 PM, Richard Arper via CnC-List > <cnc-list@cnc-list.com> wrote: > > This issue may have been discussed previously before I joined the group, but > I wanted to throw it out there. > I have a 34+ with a Yanmar 3GM30F and its terrible to start when the > temperature is maybe 50-60 degrees or less. > That's a problem in Puget Sound where we sail all year. > Once started, however, it starts perfectly all day after that with just a > couple turns. > > I've read online about others having the same problem and offering starting > procedures such as turning over with compression levers open to lubricate, > then turn over with no fuel to heat up the chambers. > There's even an air preheater that tractors use. > But this doesn't solve the problem, and it's to the point where I'm ready to > rebuild or repower. > > However, what's the root of the problem? Is it poor compression? (engine > only has 1600 hrs.) > Is it bad injectors? Other issues? Trait of this particular engine? > > My 34 had a 2QM20 that started flawlessly under any conditions, so I know > that it's not a lack of glow plugs. > > Richard Arper > rtar...@wavecable.com > C&C 34+ > Your contributions help pay the fees associated with this list and help to > keep it active. Please help by making a small contribution using PayPal at: > https://www.paypal.com/paypalme/stumurray All contributions are greatly > appreciated. Your contributions help pay the fees associated with this list and help to keep it active. Please help by making a small contribution using PayPal at: https://www.paypal.com/paypalme/stumurray All contributions are greatly appreciated.
