1401D Compression Release

[MichaelDee]

I’ve recently purchased a rebuilt gray market Yanmar YM1401D, and the seller told me to use the Compression Release to stop the engine. I’ve just acquired a translated manual, where it explicitly states NOT to use the Compression Release to do this. I don’t know enough about diesels to know exactly how the Compression Release works or what damage I might have done by using it for engine shut-down (I’ve put about 6 hours on the tach). In addition, this manual is a little unclear as to the use of Compression Release when starting. It indicates to pull the lever out, turn the key to the start position until the engine starts running, but not when to stop using the Release … it sure won’t run with the Compression Release on … I need a little diesel savvy here …

 

[Ozarker]

I doubt that you have done any damage but the proper shutdown is to simply push the throttle lever all the way in to shut off the fuel. Then turn the key off.

The compression release is to allow you to spin up the engine without the starter having to work against the compression of the engine. Makes things easier on the starter. Diesel engines are compression fired and have significantly more compression than the ignition fired engine in your car.

Once you spin it up for a few seconds, release the lever and it should start. It is actually the momentum of the flywheel that helps overcome the compression and start the engine.

When I lived in Germany back in the 70's, my German neighbor rented a plate compactor to compact an area he was replacing the cobblestones in. It was a one cyl diesel unit with no starter. I had to help him start it after he had tried three or four times and it had kicked his butt.

The process was to open the compression release, set the fuel lever to half throttle and then hand crank the flywheel. Once you got it spun up, close the compression release and pray that it started.

He couldn't get it spinning fast enough by himself so we both cranked it to get the engine spinning.

 

[Soundguy]

Don't use the compression release to stop the engine.. all that leads to is diluted oil....

The manual for both my diesels has big bold 'caution' / atchung! words stating not to do this.. or bad things will happen to you.. etc..

Soundguy

 

[hosejockey2002]

If yours is anything like mine, it will continue to run with the key off. Mine has a shutoff button just below the throttle lever. I close the throttle all the way, let it slow idle for a bit, and push the button and turn the key off. I do use the compression release when starting it cold. I crank with the release pulled until the oil light goes out, push it in and it fires right up.

 

[MichaelDee]

Thank you. You gave me a pretty good picture of what's going on. Starting up should be a lot easier now that I can picture the sequence of events. The comments from Soundguy about oil dilution make sense as well. I'm guessing the compression release holds the exhaust valves open (?), and, without compression, the fuel won't fire, so you'd have diesel fuel washing the lube oil off the cylinder walls. And, re the comment from Hosejockey, I'll be looking for that stop button somewhere around the throttle lever. You guys are better 'in three JD salesmen put together ...

 

[Soundguy]

Some units don't have the stop button. On my 1700... you throttle al lthe way back.. and then there is just a bit more 'give' to the throttle, as the injector pump is starved. I did have to adjust the throttle linkage/stop to get good shutdowns when i first got my tractor.

And like hosejockey said.. only units that have electric operated fuel puimp solenoids are key shutdown..
And also comp release is a great way to get oil pressure befroe starting..

Soundguy

 

[rich1010220]

I don't know if your 1401 shuts off the same as my 1610, but mine was having problems shutting off. I found the problem to be the foot throttle. It was sticking and even though I pushed the hand throttle to shut it off, it would not. After checking and lubing the foot throttle, it shuts down propertly.

Rich

 

[DavesTractor]

The 1401's and 1510's are the only ones I know of with the little stop "button". It is there so you can quickly run the lever all the way to low idle without accidentally shutting down. It is sort of a stop in the throw of the lever. Some people remove the button and then they act like the rest of the Yanmars, save for the ones that shut off electrically.