Yanmar 2GM20f may have cranked too long
- Thread starter Dean Strong
- Start date
Thanks for all your comments and input to my problem of why my 2gm20f stopped running.I guess to start by bleeding all my fuel lines. And see how things go from there. Need to start some place. As I'm not having much luck finding a Yanmar service person here Hartwell Ga. area. So I am kinda on my own.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,829
You have us. We may not be on the boat with you. but for the basics we can often help a fellow sailor get back to sailing.
Thanks, I replaced fuel separator. the old one was really in bad condition, with water and dirty, drained the diesel fuel tank, the bottom of the tank had water and brown slug. what a mess. removed and cleaned injectors. primed all the fuel lines. and to my surprise it started and run good. Also found out the heat exchanger did not get any raw water. took pump apart and the impeller was shot, so I put in a new one, pumps water fine now...most of the help I found on you tube...but thanks for you guys help ...
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,829
I’m curious - I have a 3GM30F. How much cranking does it take to risk backflow and hydrolock? 30 seconds? More? These engines seem to hard start and I don’t want to overdo it. I know I can shut off the sea cock, just wondering how long I can crank without worrying about it.
Even cranking 30 seconds is way too long for the good of the starter ! You might fry it !!! And that is also risky for possible hydro-lock. On the cold days of Fall & early Spring, my 3GM30F will start fairly easily with one...or two cranking of roughly 10 seconds. Providing the fuel control is pushed about halfway up. If yours still doesn't start, stop trying, wait a while to let water in the exhaust hose drain down, then close the water intake valve and have someone decompress the 3 cylinders. Run the starter 5 to 10 seconds and compress one cylinder. That one will fire up and will automatically bring the compression on the other 2. Let engine warm up a bit and take her out for a spell to make sure you have everything running right. Good luck.
30 sec. is hard on the starter as per @Claude L.-Auger.
Flooding will depend on how large your muffler is. Be sure to close your raw water inlet if your engine is feeling cranky.
Don't worry about the pump running dry as some people here have decried. That would be nothing short of a trip to the "twilight zone" as there is no way for air to enter the pump if the inlet valve is closed. It will overheat eventually as you are putting work into the pump (think friction) and will eventually cause problems but not within 30 seconds.
Cold days I won’t do more than 3 separate 10 second cranks, and if it doesn’t start up by then, I’ll close the seacock and do the cold start process (open compression valves for 5 -10 second crank, point a hair dryer in the air intake, and then give it a go with one closed, close the other 2 once it fires up).
Now that it’s warmer, I’m able to start up in about 5 seconds without using ether. I did find that the compression levers did not automatically engage once one cylinder fired - I have to manually close them if I open them.
It depends on your exhaust setup. Some have a straight down mixing elbow, others have a U shaped mixing elbow. The height difference between the muffler and the exhaust manifold will affect the amount of water it can hold.
Typically, you would not have any issues with 2x 15 second cranks. If it hasn't started by then, something is wrong. Time to close the water intake and investigate.
Are you using 2/3 to full throttle every time? Is the transmission in neutral? Is it below 10 deg C ? if it's below 10, you probably should follow the cold start procedure listed in the manual( close water intake, pull fuel shut off, open decompression levers, start for 10 seconds, open water, close decompression levers, push in fuel shutoff, do a normal start).
Do you have low compression? Stuck rings? A clogged exhaust elbow? Corrosion on the starter wire terminals? These will all affect starting performance.