Hard Starting 1998 Yanmar 2GM20

[Phil D.]

The initial start on my Yanmar 2GM20 is becomming increasingly more difficult. Subsequent starts are no problem. Runs very smooth once it gets going. Can running at low rpm or idlying for long periods of time be contributing to the problem? Any ideas would be appreciated? Thanks!

 

[Steve O.]

try this

Give it 1/2 to 3/4 throttle before you crank it, then back it down as soon as it starts. Don't over rev it.

 

[James Marohn]

Carbon deposits

If there's water mixed in with the fuel, it would be hard to start. Have you checked your water-fuel separator filter recently? Usually they come with a bleeding nut or plug on the bottom side so you can drain the water (since water is heavier than fuel, it accumulates in the bottom).Another common cause for hard starting is carbon deposits which accumulate on your injectors. When was the last time you cleaned them? Do you use any additives with your fuel?Cleaning the injectors aren't difficult at all. If you have got one already, I highly recommend the Solec Yanmar Inboards Repair Manual (available at amazon.com). Great pictures, step by step instructions, very thorough, and easy enough for the layman.Let me know if any of these helps. If not, maybe there's some other symtpoms..? White smoke? Sporadic drops in the RPM?Cheers,-j-

 

[Ralph Johnstone]

Carbon May be the Culprit .................

........... as suggested by James Marohn in the last post. According to experts (as well as Nigel) low speed idling is to be avoided at all costs due to carbon buid up and its associated problems.One problem is carbon build up on the valves. This will reduce compression on start up and cause hard starting. Try running your engine at 3500 for 5 minutes every hour the next time you are out and don't let it go below 2900 RPM which is recommended cruising RPM. This may get rid of the carbon.Hope this helps.Regards,Island Hunter

 

[Derek Rowell]

I just had a similar problem...

on a larger engine (Yanmar 4JH-TE). After a week of standing still it was very hard to start, and most often needed bleeding, but if it only stood a day or so it would start right up. I suspected an air leak in the fuel line, but I simply could not find anything. I had the yard do a "500 hour" inspection, and they found a small diesel leak in the fuel return line right at an injector. They replaced that portion of the line and it has worked perfectly ever since. They also adjusted the valves. Now it starts at the touch of the button (so far!)Derek

 

[Mark M Smith]

From Yanmar site

Do not operate for extended periods below 80% rpm. The cylinder bores will glaze causing an increase in oil consumption and blue smoke. Don't 'baby' your diesel engine!

 

[andy]

try PS (Power Service) additive, cetane booster

My 3GM30 was very hard to start. Crank for 15 seconds before 1 then 2 then 3 would blubble to life. She would start and run great the rest of the day.American Diesel fuel has a very low cetane rating. Yanmars need more. (Like premium gasoline) Since starting to use PS diesel additive (WalMart sells it) she starts with a jab of the start button, even when cold.  Try full throttle when cranking and back off after it starts.